OLD | NEW |
1 | 1 |
2 /* pngrtran.c - transforms the data in a row for PNG readers | 2 /* pngrtran.c - transforms the data in a row for PNG readers |
3 * | 3 * |
4 * Last changed in libpng 1.2.53 [February 26, 2015] | 4 * Last changed in libpng 1.6.22 [May 26, 2016] |
5 * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson | 5 * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson |
6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) | 6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) | 7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
8 * | 8 * |
9 * This code is released under the libpng license. | 9 * This code is released under the libpng license. |
10 * For conditions of distribution and use, see the disclaimer | 10 * For conditions of distribution and use, see the disclaimer |
11 * and license in png.h | 11 * and license in png.h |
12 * | 12 * |
13 * This file contains functions optionally called by an application | 13 * This file contains functions optionally called by an application |
14 * in order to tell libpng how to handle data when reading a PNG. | 14 * in order to tell libpng how to handle data when reading a PNG. |
15 * Transformations that are used in both reading and writing are | 15 * Transformations that are used in both reading and writing are |
16 * in pngtrans.c. | 16 * in pngtrans.c. |
17 */ | 17 */ |
18 | 18 |
19 #define PNG_INTERNAL | 19 #include "pngpriv.h" |
20 #define PNG_NO_PEDANTIC_WARNINGS | 20 |
21 #include "png.h" | |
22 #ifdef PNG_READ_SUPPORTED | 21 #ifdef PNG_READ_SUPPORTED |
23 | 22 |
24 /* Set the action on getting a CRC error for an ancillary or critical chunk. */ | 23 /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
25 void PNGAPI | 24 void PNGAPI |
26 png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) | 25 png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action) |
27 { | 26 { |
28 png_debug(1, "in png_set_crc_action"); | 27 png_debug(1, "in png_set_crc_action"); |
29 | 28 |
30 if (png_ptr == NULL) | 29 if (png_ptr == NULL) |
31 return; | 30 return; |
32 | 31 |
33 /* Tell libpng how we react to CRC errors in critical chunks */ | 32 /* Tell libpng how we react to CRC errors in critical chunks */ |
34 switch (crit_action) | 33 switch (crit_action) |
35 { | 34 { |
36 case PNG_CRC_NO_CHANGE: /* Leave setting as is */ | 35 case PNG_CRC_NO_CHANGE: /* Leave setting as is */ |
37 break; | 36 break; |
38 | 37 |
39 case PNG_CRC_WARN_USE: /* Warn/use data */ | 38 case PNG_CRC_WARN_USE: /* Warn/use data */ |
40 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; | 39 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
41 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; | 40 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; |
42 break; | 41 break; |
43 | 42 |
44 case PNG_CRC_QUIET_USE: /* Quiet/use data */ | 43 case PNG_CRC_QUIET_USE: /* Quiet/use data */ |
45 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; | 44 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
46 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | | 45 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | |
47 PNG_FLAG_CRC_CRITICAL_IGNORE; | 46 PNG_FLAG_CRC_CRITICAL_IGNORE; |
48 break; | 47 break; |
49 | 48 |
50 case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ | 49 case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ |
51 png_warning(png_ptr, | 50 png_warning(png_ptr, |
52 "Can't discard critical data on CRC error."); | 51 "Can't discard critical data on CRC error"); |
53 case PNG_CRC_ERROR_QUIT: /* Error/quit */ | 52 case PNG_CRC_ERROR_QUIT: /* Error/quit */ |
54 | 53 |
55 case PNG_CRC_DEFAULT: | 54 case PNG_CRC_DEFAULT: |
56 default: | 55 default: |
57 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; | 56 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
58 break; | 57 break; |
59 } | 58 } |
60 | 59 |
61 /* Tell libpng how we react to CRC errors in ancillary chunks */ | 60 /* Tell libpng how we react to CRC errors in ancillary chunks */ |
62 switch (ancil_action) | 61 switch (ancil_action) |
(...skipping 19 matching lines...) Expand all Loading... |
82 | 81 |
83 case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ | 82 case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ |
84 | 83 |
85 case PNG_CRC_DEFAULT: | 84 case PNG_CRC_DEFAULT: |
86 default: | 85 default: |
87 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; | 86 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
88 break; | 87 break; |
89 } | 88 } |
90 } | 89 } |
91 | 90 |
92 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ | 91 #ifdef PNG_READ_TRANSFORMS_SUPPORTED |
93 defined(PNG_FLOATING_POINT_SUPPORTED) | 92 /* Is it OK to set a transformation now? Only if png_start_read_image or |
| 93 * png_read_update_info have not been called. It is not necessary for the IHDR |
| 94 * to have been read in all cases; the need_IHDR parameter allows for this |
| 95 * check too. |
| 96 */ |
| 97 static int |
| 98 png_rtran_ok(png_structrp png_ptr, int need_IHDR) |
| 99 { |
| 100 if (png_ptr != NULL) |
| 101 { |
| 102 if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0) |
| 103 png_app_error(png_ptr, |
| 104 "invalid after png_start_read_image or png_read_update_info"); |
| 105 |
| 106 else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0) |
| 107 png_app_error(png_ptr, "invalid before the PNG header has been read"); |
| 108 |
| 109 else |
| 110 { |
| 111 /* Turn on failure to initialize correctly for all transforms. */ |
| 112 png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED; |
| 113 |
| 114 return 1; /* Ok */ |
| 115 } |
| 116 } |
| 117 |
| 118 return 0; /* no png_error possible! */ |
| 119 } |
| 120 #endif |
| 121 |
| 122 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
94 /* Handle alpha and tRNS via a background color */ | 123 /* Handle alpha and tRNS via a background color */ |
95 void PNGAPI | 124 void PNGFAPI |
96 png_set_background(png_structp png_ptr, | 125 png_set_background_fixed(png_structrp png_ptr, |
97 png_color_16p background_color, int background_gamma_code, | 126 png_const_color_16p background_color, int background_gamma_code, |
98 int need_expand, double background_gamma) | 127 int need_expand, png_fixed_point background_gamma) |
99 { | 128 { |
100 png_debug(1, "in png_set_background"); | 129 png_debug(1, "in png_set_background_fixed"); |
101 | 130 |
102 if (png_ptr == NULL) | 131 if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL) |
103 return; | 132 return; |
| 133 |
104 if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) | 134 if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) |
105 { | 135 { |
106 png_warning(png_ptr, "Application must supply a known background gamma"); | 136 png_warning(png_ptr, "Application must supply a known background gamma"); |
107 return; | 137 return; |
108 } | 138 } |
109 | 139 |
110 png_ptr->transformations |= PNG_BACKGROUND; | 140 png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA; |
111 png_memcpy(&(png_ptr->background), background_color, | 141 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
112 png_sizeof(png_color_16)); | 142 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
113 png_ptr->background_gamma = (float)background_gamma; | 143 |
| 144 png_ptr->background = *background_color; |
| 145 png_ptr->background_gamma = background_gamma; |
114 png_ptr->background_gamma_type = (png_byte)(background_gamma_code); | 146 png_ptr->background_gamma_type = (png_byte)(background_gamma_code); |
115 png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); | 147 if (need_expand != 0) |
116 } | 148 png_ptr->transformations |= PNG_BACKGROUND_EXPAND; |
117 #endif | 149 else |
118 | 150 png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; |
119 #ifdef PNG_READ_16_TO_8_SUPPORTED | 151 } |
120 /* Strip 16 bit depth files to 8 bit depth */ | 152 |
121 void PNGAPI | 153 # ifdef PNG_FLOATING_POINT_SUPPORTED |
122 png_set_strip_16(png_structp png_ptr) | 154 void PNGAPI |
| 155 png_set_background(png_structrp png_ptr, |
| 156 png_const_color_16p background_color, int background_gamma_code, |
| 157 int need_expand, double background_gamma) |
| 158 { |
| 159 png_set_background_fixed(png_ptr, background_color, background_gamma_code, |
| 160 need_expand, png_fixed(png_ptr, background_gamma, "png_set_background")); |
| 161 } |
| 162 # endif /* FLOATING_POINT */ |
| 163 #endif /* READ_BACKGROUND */ |
| 164 |
| 165 /* Scale 16-bit depth files to 8-bit depth. If both of these are set then the |
| 166 * one that pngrtran does first (scale) happens. This is necessary to allow the |
| 167 * TRANSFORM and API behavior to be somewhat consistent, and it's simpler. |
| 168 */ |
| 169 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
| 170 void PNGAPI |
| 171 png_set_scale_16(png_structrp png_ptr) |
| 172 { |
| 173 png_debug(1, "in png_set_scale_16"); |
| 174 |
| 175 if (png_rtran_ok(png_ptr, 0) == 0) |
| 176 return; |
| 177 |
| 178 png_ptr->transformations |= PNG_SCALE_16_TO_8; |
| 179 } |
| 180 #endif |
| 181 |
| 182 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
| 183 /* Chop 16-bit depth files to 8-bit depth */ |
| 184 void PNGAPI |
| 185 png_set_strip_16(png_structrp png_ptr) |
123 { | 186 { |
124 png_debug(1, "in png_set_strip_16"); | 187 png_debug(1, "in png_set_strip_16"); |
125 | 188 |
126 if (png_ptr == NULL) | 189 if (png_rtran_ok(png_ptr, 0) == 0) |
127 return; | 190 return; |
| 191 |
128 png_ptr->transformations |= PNG_16_TO_8; | 192 png_ptr->transformations |= PNG_16_TO_8; |
129 } | 193 } |
130 #endif | 194 #endif |
131 | 195 |
132 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | 196 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
133 void PNGAPI | 197 void PNGAPI |
134 png_set_strip_alpha(png_structp png_ptr) | 198 png_set_strip_alpha(png_structrp png_ptr) |
135 { | 199 { |
136 png_debug(1, "in png_set_strip_alpha"); | 200 png_debug(1, "in png_set_strip_alpha"); |
137 | 201 |
138 if (png_ptr == NULL) | 202 if (png_rtran_ok(png_ptr, 0) == 0) |
139 return; | 203 return; |
140 png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; | 204 |
141 } | 205 png_ptr->transformations |= PNG_STRIP_ALPHA; |
142 #endif | 206 } |
143 | 207 #endif |
144 #ifdef PNG_READ_DITHER_SUPPORTED | 208 |
145 /* Dither file to 8 bit. Supply a palette, the current number | 209 #if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED) |
| 210 static png_fixed_point |
| 211 translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma, |
| 212 int is_screen) |
| 213 { |
| 214 /* Check for flag values. The main reason for having the old Mac value as a |
| 215 * flag is that it is pretty near impossible to work out what the correct |
| 216 * value is from Apple documentation - a working Mac system is needed to |
| 217 * discover the value! |
| 218 */ |
| 219 if (output_gamma == PNG_DEFAULT_sRGB || |
| 220 output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB) |
| 221 { |
| 222 /* If there is no sRGB support this just sets the gamma to the standard |
| 223 * sRGB value. (This is a side effect of using this function!) |
| 224 */ |
| 225 # ifdef PNG_READ_sRGB_SUPPORTED |
| 226 png_ptr->flags |= PNG_FLAG_ASSUME_sRGB; |
| 227 # else |
| 228 PNG_UNUSED(png_ptr) |
| 229 # endif |
| 230 if (is_screen != 0) |
| 231 output_gamma = PNG_GAMMA_sRGB; |
| 232 else |
| 233 output_gamma = PNG_GAMMA_sRGB_INVERSE; |
| 234 } |
| 235 |
| 236 else if (output_gamma == PNG_GAMMA_MAC_18 || |
| 237 output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18) |
| 238 { |
| 239 if (is_screen != 0) |
| 240 output_gamma = PNG_GAMMA_MAC_OLD; |
| 241 else |
| 242 output_gamma = PNG_GAMMA_MAC_INVERSE; |
| 243 } |
| 244 |
| 245 return output_gamma; |
| 246 } |
| 247 |
| 248 # ifdef PNG_FLOATING_POINT_SUPPORTED |
| 249 static png_fixed_point |
| 250 convert_gamma_value(png_structrp png_ptr, double output_gamma) |
| 251 { |
| 252 /* The following silently ignores cases where fixed point (times 100,000) |
| 253 * gamma values are passed to the floating point API. This is safe and it |
| 254 * means the fixed point constants work just fine with the floating point |
| 255 * API. The alternative would just lead to undetected errors and spurious |
| 256 * bug reports. Negative values fail inside the _fixed API unless they |
| 257 * correspond to the flag values. |
| 258 */ |
| 259 if (output_gamma > 0 && output_gamma < 128) |
| 260 output_gamma *= PNG_FP_1; |
| 261 |
| 262 /* This preserves -1 and -2 exactly: */ |
| 263 output_gamma = floor(output_gamma + .5); |
| 264 |
| 265 if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN) |
| 266 png_fixed_error(png_ptr, "gamma value"); |
| 267 |
| 268 return (png_fixed_point)output_gamma; |
| 269 } |
| 270 # endif |
| 271 #endif /* READ_ALPHA_MODE || READ_GAMMA */ |
| 272 |
| 273 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
| 274 void PNGFAPI |
| 275 png_set_alpha_mode_fixed(png_structrp png_ptr, int mode, |
| 276 png_fixed_point output_gamma) |
| 277 { |
| 278 int compose = 0; |
| 279 png_fixed_point file_gamma; |
| 280 |
| 281 png_debug(1, "in png_set_alpha_mode"); |
| 282 |
| 283 if (png_rtran_ok(png_ptr, 0) == 0) |
| 284 return; |
| 285 |
| 286 output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/); |
| 287 |
| 288 /* Validate the value to ensure it is in a reasonable range. The value |
| 289 * is expected to be 1 or greater, but this range test allows for some |
| 290 * viewing correction values. The intent is to weed out users of this API |
| 291 * who use the inverse of the gamma value accidentally! Since some of these |
| 292 * values are reasonable this may have to be changed: |
| 293 * |
| 294 * 1.6.x: changed from 0.07..3 to 0.01..100 (to accomodate the optimal 16-bit |
| 295 * gamma of 36, and its reciprocal.) |
| 296 */ |
| 297 if (output_gamma < 1000 || output_gamma > 10000000) |
| 298 png_error(png_ptr, "output gamma out of expected range"); |
| 299 |
| 300 /* The default file gamma is the inverse of the output gamma; the output |
| 301 * gamma may be changed below so get the file value first: |
| 302 */ |
| 303 file_gamma = png_reciprocal(output_gamma); |
| 304 |
| 305 /* There are really 8 possibilities here, composed of any combination |
| 306 * of: |
| 307 * |
| 308 * premultiply the color channels |
| 309 * do not encode non-opaque pixels |
| 310 * encode the alpha as well as the color channels |
| 311 * |
| 312 * The differences disappear if the input/output ('screen') gamma is 1.0, |
| 313 * because then the encoding is a no-op and there is only the choice of |
| 314 * premultiplying the color channels or not. |
| 315 * |
| 316 * png_set_alpha_mode and png_set_background interact because both use |
| 317 * png_compose to do the work. Calling both is only useful when |
| 318 * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along |
| 319 * with a default gamma value. Otherwise PNG_COMPOSE must not be set. |
| 320 */ |
| 321 switch (mode) |
| 322 { |
| 323 case PNG_ALPHA_PNG: /* default: png standard */ |
| 324 /* No compose, but it may be set by png_set_background! */ |
| 325 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
| 326 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
| 327 break; |
| 328 |
| 329 case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */ |
| 330 compose = 1; |
| 331 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
| 332 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
| 333 /* The output is linear: */ |
| 334 output_gamma = PNG_FP_1; |
| 335 break; |
| 336 |
| 337 case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */ |
| 338 compose = 1; |
| 339 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
| 340 png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA; |
| 341 /* output_gamma records the encoding of opaque pixels! */ |
| 342 break; |
| 343 |
| 344 case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */ |
| 345 compose = 1; |
| 346 png_ptr->transformations |= PNG_ENCODE_ALPHA; |
| 347 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
| 348 break; |
| 349 |
| 350 default: |
| 351 png_error(png_ptr, "invalid alpha mode"); |
| 352 } |
| 353 |
| 354 /* Only set the default gamma if the file gamma has not been set (this has |
| 355 * the side effect that the gamma in a second call to png_set_alpha_mode will |
| 356 * be ignored.) |
| 357 */ |
| 358 if (png_ptr->colorspace.gamma == 0) |
| 359 { |
| 360 png_ptr->colorspace.gamma = file_gamma; |
| 361 png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; |
| 362 } |
| 363 |
| 364 /* But always set the output gamma: */ |
| 365 png_ptr->screen_gamma = output_gamma; |
| 366 |
| 367 /* Finally, if pre-multiplying, set the background fields to achieve the |
| 368 * desired result. |
| 369 */ |
| 370 if (compose != 0) |
| 371 { |
| 372 /* And obtain alpha pre-multiplication by composing on black: */ |
| 373 memset(&png_ptr->background, 0, (sizeof png_ptr->background)); |
| 374 png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */ |
| 375 png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE; |
| 376 png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND; |
| 377 |
| 378 if ((png_ptr->transformations & PNG_COMPOSE) != 0) |
| 379 png_error(png_ptr, |
| 380 "conflicting calls to set alpha mode and background"); |
| 381 |
| 382 png_ptr->transformations |= PNG_COMPOSE; |
| 383 } |
| 384 } |
| 385 |
| 386 # ifdef PNG_FLOATING_POINT_SUPPORTED |
| 387 void PNGAPI |
| 388 png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma) |
| 389 { |
| 390 png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr, |
| 391 output_gamma)); |
| 392 } |
| 393 # endif |
| 394 #endif |
| 395 |
| 396 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
| 397 /* Dither file to 8-bit. Supply a palette, the current number |
146 * of elements in the palette, the maximum number of elements | 398 * of elements in the palette, the maximum number of elements |
147 * allowed, and a histogram if possible. If the current number | 399 * allowed, and a histogram if possible. If the current number |
148 * of colors is greater then the maximum number, the palette will be | 400 * of colors is greater than the maximum number, the palette will be |
149 * modified to fit in the maximum number. "full_dither" indicates | 401 * modified to fit in the maximum number. "full_quantize" indicates |
150 * whether we need a dithering cube set up for RGB images, or if we | 402 * whether we need a quantizing cube set up for RGB images, or if we |
151 * simply are reducing the number of colors in a paletted image. | 403 * simply are reducing the number of colors in a paletted image. |
152 */ | 404 */ |
153 | 405 |
154 typedef struct png_dsort_struct | 406 typedef struct png_dsort_struct |
155 { | 407 { |
156 struct png_dsort_struct FAR * next; | 408 struct png_dsort_struct * next; |
157 png_byte left; | 409 png_byte left; |
158 png_byte right; | 410 png_byte right; |
159 } png_dsort; | 411 } png_dsort; |
160 typedef png_dsort FAR * png_dsortp; | 412 typedef png_dsort * png_dsortp; |
161 typedef png_dsort FAR * FAR * png_dsortpp; | 413 typedef png_dsort * * png_dsortpp; |
162 | 414 |
163 void PNGAPI | 415 void PNGAPI |
164 png_set_dither(png_structp png_ptr, png_colorp palette, | 416 png_set_quantize(png_structrp png_ptr, png_colorp palette, |
165 int num_palette, int maximum_colors, png_uint_16p histogram, | 417 int num_palette, int maximum_colors, png_const_uint_16p histogram, |
166 int full_dither) | 418 int full_quantize) |
167 { | 419 { |
168 png_debug(1, "in png_set_dither"); | 420 png_debug(1, "in png_set_quantize"); |
169 | 421 |
170 if (png_ptr == NULL) | 422 if (png_rtran_ok(png_ptr, 0) == 0) |
171 return; | 423 return; |
172 png_ptr->transformations |= PNG_DITHER; | 424 |
173 | 425 png_ptr->transformations |= PNG_QUANTIZE; |
174 if (!full_dither) | 426 |
| 427 if (full_quantize == 0) |
175 { | 428 { |
176 int i; | 429 int i; |
177 | 430 |
178 png_ptr->dither_index = (png_bytep)png_malloc(png_ptr, | 431 png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr, |
179 (png_uint_32)(num_palette * png_sizeof(png_byte))); | 432 (png_uint_32)(num_palette * (sizeof (png_byte)))); |
180 for (i = 0; i < num_palette; i++) | 433 for (i = 0; i < num_palette; i++) |
181 png_ptr->dither_index[i] = (png_byte)i; | 434 png_ptr->quantize_index[i] = (png_byte)i; |
182 } | 435 } |
183 | 436 |
184 if (num_palette > maximum_colors) | 437 if (num_palette > maximum_colors) |
185 { | 438 { |
186 if (histogram != NULL) | 439 if (histogram != NULL) |
187 { | 440 { |
188 /* This is easy enough, just throw out the least used colors. | 441 /* This is easy enough, just throw out the least used colors. |
189 * Perhaps not the best solution, but good enough. | 442 * Perhaps not the best solution, but good enough. |
190 */ | 443 */ |
191 | 444 |
192 int i; | 445 int i; |
193 | 446 |
194 /* Initialize an array to sort colors */ | 447 /* Initialize an array to sort colors */ |
195 png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr, | 448 png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr, |
196 (png_uint_32)(num_palette * png_sizeof(png_byte))); | 449 (png_uint_32)(num_palette * (sizeof (png_byte)))); |
197 | 450 |
198 /* Initialize the dither_sort array */ | 451 /* Initialize the quantize_sort array */ |
199 for (i = 0; i < num_palette; i++) | 452 for (i = 0; i < num_palette; i++) |
200 png_ptr->dither_sort[i] = (png_byte)i; | 453 png_ptr->quantize_sort[i] = (png_byte)i; |
201 | 454 |
202 /* Find the least used palette entries by starting a | 455 /* Find the least used palette entries by starting a |
203 * bubble sort, and running it until we have sorted | 456 * bubble sort, and running it until we have sorted |
204 * out enough colors. Note that we don't care about | 457 * out enough colors. Note that we don't care about |
205 * sorting all the colors, just finding which are | 458 * sorting all the colors, just finding which are |
206 * least used. | 459 * least used. |
207 */ | 460 */ |
208 | 461 |
209 for (i = num_palette - 1; i >= maximum_colors; i--) | 462 for (i = num_palette - 1; i >= maximum_colors; i--) |
210 { | 463 { |
211 int done; /* To stop early if the list is pre-sorted */ | 464 int done; /* To stop early if the list is pre-sorted */ |
212 int j; | 465 int j; |
213 | 466 |
214 done = 1; | 467 done = 1; |
215 for (j = 0; j < i; j++) | 468 for (j = 0; j < i; j++) |
216 { | 469 { |
217 if (histogram[png_ptr->dither_sort[j]] | 470 if (histogram[png_ptr->quantize_sort[j]] |
218 < histogram[png_ptr->dither_sort[j + 1]]) | 471 < histogram[png_ptr->quantize_sort[j + 1]]) |
219 { | 472 { |
220 png_byte t; | 473 png_byte t; |
221 | 474 |
222 t = png_ptr->dither_sort[j]; | 475 t = png_ptr->quantize_sort[j]; |
223 png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1]; | 476 png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1]; |
224 png_ptr->dither_sort[j + 1] = t; | 477 png_ptr->quantize_sort[j + 1] = t; |
225 done = 0; | 478 done = 0; |
226 } | 479 } |
227 } | 480 } |
228 if (done) | 481 |
| 482 if (done != 0) |
229 break; | 483 break; |
230 } | 484 } |
231 | 485 |
232 /* Swap the palette around, and set up a table, if necessary */ | 486 /* Swap the palette around, and set up a table, if necessary */ |
233 if (full_dither) | 487 if (full_quantize != 0) |
234 { | 488 { |
235 int j = num_palette; | 489 int j = num_palette; |
236 | 490 |
237 /* Put all the useful colors within the max, but don't | 491 /* Put all the useful colors within the max, but don't |
238 * move the others. | 492 * move the others. |
239 */ | 493 */ |
240 for (i = 0; i < maximum_colors; i++) | 494 for (i = 0; i < maximum_colors; i++) |
241 { | 495 { |
242 if ((int)png_ptr->dither_sort[i] >= maximum_colors) | 496 if ((int)png_ptr->quantize_sort[i] >= maximum_colors) |
243 { | 497 { |
244 do | 498 do |
245 j--; | 499 j--; |
246 while ((int)png_ptr->dither_sort[j] >= maximum_colors); | 500 while ((int)png_ptr->quantize_sort[j] >= maximum_colors); |
| 501 |
247 palette[i] = palette[j]; | 502 palette[i] = palette[j]; |
248 } | 503 } |
249 } | 504 } |
250 } | 505 } |
251 else | 506 else |
252 { | 507 { |
253 int j = num_palette; | 508 int j = num_palette; |
254 | 509 |
255 /* Move all the used colors inside the max limit, and | 510 /* Move all the used colors inside the max limit, and |
256 * develop a translation table. | 511 * develop a translation table. |
257 */ | 512 */ |
258 for (i = 0; i < maximum_colors; i++) | 513 for (i = 0; i < maximum_colors; i++) |
259 { | 514 { |
260 /* Only move the colors we need to */ | 515 /* Only move the colors we need to */ |
261 if ((int)png_ptr->dither_sort[i] >= maximum_colors) | 516 if ((int)png_ptr->quantize_sort[i] >= maximum_colors) |
262 { | 517 { |
263 png_color tmp_color; | 518 png_color tmp_color; |
264 | 519 |
265 do | 520 do |
266 j--; | 521 j--; |
267 while ((int)png_ptr->dither_sort[j] >= maximum_colors); | 522 while ((int)png_ptr->quantize_sort[j] >= maximum_colors); |
268 | 523 |
269 tmp_color = palette[j]; | 524 tmp_color = palette[j]; |
270 palette[j] = palette[i]; | 525 palette[j] = palette[i]; |
271 palette[i] = tmp_color; | 526 palette[i] = tmp_color; |
272 /* Indicate where the color went */ | 527 /* Indicate where the color went */ |
273 png_ptr->dither_index[j] = (png_byte)i; | 528 png_ptr->quantize_index[j] = (png_byte)i; |
274 png_ptr->dither_index[i] = (png_byte)j; | 529 png_ptr->quantize_index[i] = (png_byte)j; |
275 } | 530 } |
276 } | 531 } |
277 | 532 |
278 /* Find closest color for those colors we are not using */ | 533 /* Find closest color for those colors we are not using */ |
279 for (i = 0; i < num_palette; i++) | 534 for (i = 0; i < num_palette; i++) |
280 { | 535 { |
281 if ((int)png_ptr->dither_index[i] >= maximum_colors) | 536 if ((int)png_ptr->quantize_index[i] >= maximum_colors) |
282 { | 537 { |
283 int min_d, k, min_k, d_index; | 538 int min_d, k, min_k, d_index; |
284 | 539 |
285 /* Find the closest color to one we threw out */ | 540 /* Find the closest color to one we threw out */ |
286 d_index = png_ptr->dither_index[i]; | 541 d_index = png_ptr->quantize_index[i]; |
287 min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); | 542 min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); |
288 for (k = 1, min_k = 0; k < maximum_colors; k++) | 543 for (k = 1, min_k = 0; k < maximum_colors; k++) |
289 { | 544 { |
290 int d; | 545 int d; |
291 | 546 |
292 d = PNG_COLOR_DIST(palette[d_index], palette[k]); | 547 d = PNG_COLOR_DIST(palette[d_index], palette[k]); |
293 | 548 |
294 if (d < min_d) | 549 if (d < min_d) |
295 { | 550 { |
296 min_d = d; | 551 min_d = d; |
297 min_k = k; | 552 min_k = k; |
298 } | 553 } |
299 } | 554 } |
300 /* Point to closest color */ | 555 /* Point to closest color */ |
301 png_ptr->dither_index[i] = (png_byte)min_k; | 556 png_ptr->quantize_index[i] = (png_byte)min_k; |
302 } | 557 } |
303 } | 558 } |
304 } | 559 } |
305 png_free(png_ptr, png_ptr->dither_sort); | 560 png_free(png_ptr, png_ptr->quantize_sort); |
306 png_ptr->dither_sort = NULL; | 561 png_ptr->quantize_sort = NULL; |
307 } | 562 } |
308 else | 563 else |
309 { | 564 { |
310 /* This is much harder to do simply (and quickly). Perhaps | 565 /* This is much harder to do simply (and quickly). Perhaps |
311 * we need to go through a median cut routine, but those | 566 * we need to go through a median cut routine, but those |
312 * don't always behave themselves with only a few colors | 567 * don't always behave themselves with only a few colors |
313 * as input. So we will just find the closest two colors, | 568 * as input. So we will just find the closest two colors, |
314 * and throw out one of them (chosen somewhat randomly). | 569 * and throw out one of them (chosen somewhat randomly). |
315 * [We don't understand this at all, so if someone wants to | 570 * [We don't understand this at all, so if someone wants to |
316 * work on improving it, be our guest - AED, GRP] | 571 * work on improving it, be our guest - AED, GRP] |
317 */ | 572 */ |
318 int i; | 573 int i; |
319 int max_d; | 574 int max_d; |
320 int num_new_palette; | 575 int num_new_palette; |
321 png_dsortp t; | 576 png_dsortp t; |
322 png_dsortpp hash; | 577 png_dsortpp hash; |
323 | 578 |
324 t = NULL; | 579 t = NULL; |
325 | 580 |
326 /* Initialize palette index arrays */ | 581 /* Initialize palette index arrays */ |
327 png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, | 582 png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, |
328 (png_uint_32)(num_palette * png_sizeof(png_byte))); | 583 (png_uint_32)(num_palette * (sizeof (png_byte)))); |
329 png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, | 584 png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, |
330 (png_uint_32)(num_palette * png_sizeof(png_byte))); | 585 (png_uint_32)(num_palette * (sizeof (png_byte)))); |
331 | 586 |
332 /* Initialize the sort array */ | 587 /* Initialize the sort array */ |
333 for (i = 0; i < num_palette; i++) | 588 for (i = 0; i < num_palette; i++) |
334 { | 589 { |
335 png_ptr->index_to_palette[i] = (png_byte)i; | 590 png_ptr->index_to_palette[i] = (png_byte)i; |
336 png_ptr->palette_to_index[i] = (png_byte)i; | 591 png_ptr->palette_to_index[i] = (png_byte)i; |
337 } | 592 } |
338 | 593 |
339 hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 * | 594 hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 * |
340 png_sizeof(png_dsortp))); | 595 (sizeof (png_dsortp)))); |
341 | 596 |
342 num_new_palette = num_palette; | 597 num_new_palette = num_palette; |
343 | 598 |
344 /* Initial wild guess at how far apart the farthest pixel | 599 /* Initial wild guess at how far apart the farthest pixel |
345 * pair we will be eliminating will be. Larger | 600 * pair we will be eliminating will be. Larger |
346 * numbers mean more areas will be allocated, Smaller | 601 * numbers mean more areas will be allocated, Smaller |
347 * numbers run the risk of not saving enough data, and | 602 * numbers run the risk of not saving enough data, and |
348 * having to do this all over again. | 603 * having to do this all over again. |
349 * | 604 * |
350 * I have not done extensive checking on this number. | 605 * I have not done extensive checking on this number. |
351 */ | 606 */ |
352 max_d = 96; | 607 max_d = 96; |
353 | 608 |
354 while (num_new_palette > maximum_colors) | 609 while (num_new_palette > maximum_colors) |
355 { | 610 { |
356 for (i = 0; i < num_new_palette - 1; i++) | 611 for (i = 0; i < num_new_palette - 1; i++) |
357 { | 612 { |
358 int j; | 613 int j; |
359 | 614 |
360 for (j = i + 1; j < num_new_palette; j++) | 615 for (j = i + 1; j < num_new_palette; j++) |
361 { | 616 { |
362 int d; | 617 int d; |
363 | 618 |
364 d = PNG_COLOR_DIST(palette[i], palette[j]); | 619 d = PNG_COLOR_DIST(palette[i], palette[j]); |
365 | 620 |
366 if (d <= max_d) | 621 if (d <= max_d) |
367 { | 622 { |
368 | 623 |
369 t = (png_dsortp)png_malloc_warn(png_ptr, | 624 t = (png_dsortp)png_malloc_warn(png_ptr, |
370 (png_uint_32)(png_sizeof(png_dsort))); | 625 (png_uint_32)(sizeof (png_dsort))); |
| 626 |
371 if (t == NULL) | 627 if (t == NULL) |
372 break; | 628 break; |
| 629 |
373 t->next = hash[d]; | 630 t->next = hash[d]; |
374 t->left = (png_byte)i; | 631 t->left = (png_byte)i; |
375 t->right = (png_byte)j; | 632 t->right = (png_byte)j; |
376 hash[d] = t; | 633 hash[d] = t; |
377 } | 634 } |
378 } | 635 } |
379 if (t == NULL) | 636 if (t == NULL) |
380 break; | 637 break; |
381 } | 638 } |
382 | 639 |
383 if (t != NULL) | 640 if (t != NULL) |
384 for (i = 0; i <= max_d; i++) | 641 for (i = 0; i <= max_d; i++) |
385 { | 642 { |
386 if (hash[i] != NULL) | 643 if (hash[i] != NULL) |
387 { | 644 { |
388 png_dsortp p; | 645 png_dsortp p; |
389 | 646 |
390 for (p = hash[i]; p; p = p->next) | 647 for (p = hash[i]; p; p = p->next) |
391 { | 648 { |
392 if ((int)png_ptr->index_to_palette[p->left] | 649 if ((int)png_ptr->index_to_palette[p->left] |
393 < num_new_palette && | 650 < num_new_palette && |
394 (int)png_ptr->index_to_palette[p->right] | 651 (int)png_ptr->index_to_palette[p->right] |
395 < num_new_palette) | 652 < num_new_palette) |
396 { | 653 { |
397 int j, next_j; | 654 int j, next_j; |
398 | 655 |
399 if (num_new_palette & 0x01) | 656 if (num_new_palette & 0x01) |
400 { | 657 { |
401 j = p->left; | 658 j = p->left; |
402 next_j = p->right; | 659 next_j = p->right; |
403 } | 660 } |
404 else | 661 else |
405 { | 662 { |
406 j = p->right; | 663 j = p->right; |
407 next_j = p->left; | 664 next_j = p->left; |
408 } | 665 } |
409 | 666 |
410 num_new_palette--; | 667 num_new_palette--; |
411 palette[png_ptr->index_to_palette[j]] | 668 palette[png_ptr->index_to_palette[j]] |
412 = palette[num_new_palette]; | 669 = palette[num_new_palette]; |
413 if (!full_dither) | 670 if (full_quantize == 0) |
414 { | 671 { |
415 int k; | 672 int k; |
416 | 673 |
417 for (k = 0; k < num_palette; k++) | 674 for (k = 0; k < num_palette; k++) |
418 { | 675 { |
419 if (png_ptr->dither_index[k] == | 676 if (png_ptr->quantize_index[k] == |
420 png_ptr->index_to_palette[j]) | 677 png_ptr->index_to_palette[j]) |
421 png_ptr->dither_index[k] = | 678 png_ptr->quantize_index[k] = |
422 png_ptr->index_to_palette[next_j]; | 679 png_ptr->index_to_palette[next_j]; |
423 if ((int)png_ptr->dither_index[k] == | 680 |
424 num_new_palette) | 681 if ((int)png_ptr->quantize_index[k] == |
425 png_ptr->dither_index[k] = | 682 num_new_palette) |
426 png_ptr->index_to_palette[j]; | 683 png_ptr->quantize_index[k] = |
| 684 png_ptr->index_to_palette[j]; |
427 } | 685 } |
428 } | 686 } |
429 | 687 |
430 png_ptr->index_to_palette[png_ptr->palette_to_index | 688 png_ptr->index_to_palette[png_ptr->palette_to_index |
431 [num_new_palette]] = png_ptr->index_to_palette[j]; | 689 [num_new_palette]] = png_ptr->index_to_palette[j]; |
| 690 |
432 png_ptr->palette_to_index[png_ptr->index_to_palette[j]] | 691 png_ptr->palette_to_index[png_ptr->index_to_palette[j]] |
433 = png_ptr->palette_to_index[num_new_palette]; | 692 = png_ptr->palette_to_index[num_new_palette]; |
434 | 693 |
435 png_ptr->index_to_palette[j] = | 694 png_ptr->index_to_palette[j] = |
436 (png_byte)num_new_palette; | 695 (png_byte)num_new_palette; |
| 696 |
437 png_ptr->palette_to_index[num_new_palette] = | 697 png_ptr->palette_to_index[num_new_palette] = |
438 (png_byte)j; | 698 (png_byte)j; |
439 } | 699 } |
440 if (num_new_palette <= maximum_colors) | 700 if (num_new_palette <= maximum_colors) |
441 break; | 701 break; |
442 } | 702 } |
443 if (num_new_palette <= maximum_colors) | 703 if (num_new_palette <= maximum_colors) |
444 break; | 704 break; |
445 } | 705 } |
446 } | 706 } |
(...skipping 21 matching lines...) Expand all Loading... |
468 png_ptr->index_to_palette = NULL; | 728 png_ptr->index_to_palette = NULL; |
469 } | 729 } |
470 num_palette = maximum_colors; | 730 num_palette = maximum_colors; |
471 } | 731 } |
472 if (png_ptr->palette == NULL) | 732 if (png_ptr->palette == NULL) |
473 { | 733 { |
474 png_ptr->palette = palette; | 734 png_ptr->palette = palette; |
475 } | 735 } |
476 png_ptr->num_palette = (png_uint_16)num_palette; | 736 png_ptr->num_palette = (png_uint_16)num_palette; |
477 | 737 |
478 if (full_dither) | 738 if (full_quantize != 0) |
479 { | 739 { |
480 int i; | 740 int i; |
481 png_bytep distance; | 741 png_bytep distance; |
482 int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + | 742 int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS + |
483 PNG_DITHER_BLUE_BITS; | 743 PNG_QUANTIZE_BLUE_BITS; |
484 int num_red = (1 << PNG_DITHER_RED_BITS); | 744 int num_red = (1 << PNG_QUANTIZE_RED_BITS); |
485 int num_green = (1 << PNG_DITHER_GREEN_BITS); | 745 int num_green = (1 << PNG_QUANTIZE_GREEN_BITS); |
486 int num_blue = (1 << PNG_DITHER_BLUE_BITS); | 746 int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS); |
487 png_size_t num_entries = ((png_size_t)1 << total_bits); | 747 png_size_t num_entries = ((png_size_t)1 << total_bits); |
488 | 748 |
489 png_ptr->palette_lookup = (png_bytep )png_calloc(png_ptr, | 749 png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr, |
490 (png_uint_32)(num_entries * png_sizeof(png_byte))); | 750 (png_uint_32)(num_entries * (sizeof (png_byte)))); |
491 | 751 |
492 distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * | 752 distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * |
493 png_sizeof(png_byte))); | 753 (sizeof (png_byte)))); |
494 png_memset(distance, 0xff, num_entries * png_sizeof(png_byte)); | 754 |
| 755 memset(distance, 0xff, num_entries * (sizeof (png_byte))); |
495 | 756 |
496 for (i = 0; i < num_palette; i++) | 757 for (i = 0; i < num_palette; i++) |
497 { | 758 { |
498 int ir, ig, ib; | 759 int ir, ig, ib; |
499 int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); | 760 int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS)); |
500 int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); | 761 int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS)); |
501 int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); | 762 int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS)); |
502 | 763 |
503 for (ir = 0; ir < num_red; ir++) | 764 for (ir = 0; ir < num_red; ir++) |
504 { | 765 { |
505 /* int dr = abs(ir - r); */ | 766 /* int dr = abs(ir - r); */ |
506 int dr = ((ir > r) ? ir - r : r - ir); | 767 int dr = ((ir > r) ? ir - r : r - ir); |
507 int index_r = (ir << (PNG_DITHER_BLUE_BITS + | 768 int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS + |
508 PNG_DITHER_GREEN_BITS)); | 769 PNG_QUANTIZE_GREEN_BITS)); |
509 | 770 |
510 for (ig = 0; ig < num_green; ig++) | 771 for (ig = 0; ig < num_green; ig++) |
511 { | 772 { |
512 /* int dg = abs(ig - g); */ | 773 /* int dg = abs(ig - g); */ |
513 int dg = ((ig > g) ? ig - g : g - ig); | 774 int dg = ((ig > g) ? ig - g : g - ig); |
514 int dt = dr + dg; | 775 int dt = dr + dg; |
515 int dm = ((dr > dg) ? dr : dg); | 776 int dm = ((dr > dg) ? dr : dg); |
516 int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); | 777 int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS); |
517 | 778 |
518 for (ib = 0; ib < num_blue; ib++) | 779 for (ib = 0; ib < num_blue; ib++) |
519 { | 780 { |
520 int d_index = index_g | ib; | 781 int d_index = index_g | ib; |
521 /* int db = abs(ib - b); */ | 782 /* int db = abs(ib - b); */ |
522 int db = ((ib > b) ? ib - b : b - ib); | 783 int db = ((ib > b) ? ib - b : b - ib); |
523 int dmax = ((dm > db) ? dm : db); | 784 int dmax = ((dm > db) ? dm : db); |
524 int d = dmax + dt + db; | 785 int d = dmax + dt + db; |
525 | 786 |
526 if (d < (int)distance[d_index]) | 787 if (d < (int)distance[d_index]) |
527 { | 788 { |
528 distance[d_index] = (png_byte)d; | 789 distance[d_index] = (png_byte)d; |
529 png_ptr->palette_lookup[d_index] = (png_byte)i; | 790 png_ptr->palette_lookup[d_index] = (png_byte)i; |
530 } | 791 } |
531 } | 792 } |
532 } | 793 } |
533 } | 794 } |
534 } | 795 } |
535 | 796 |
536 png_free(png_ptr, distance); | 797 png_free(png_ptr, distance); |
537 } | 798 } |
538 } | 799 } |
539 #endif | 800 #endif /* READ_QUANTIZE */ |
540 | 801 |
541 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) | 802 #ifdef PNG_READ_GAMMA_SUPPORTED |
542 /* Transform the image from the file_gamma to the screen_gamma. We | 803 void PNGFAPI |
543 * only do transformations on images where the file_gamma and screen_gamma | 804 png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma, |
544 * are not close reciprocals, otherwise it slows things down slightly, and | 805 png_fixed_point file_gamma) |
545 * also needlessly introduces small errors. | |
546 * | |
547 * We will turn off gamma transformation later if no semitransparent entries | |
548 * are present in the tRNS array for palette images. We can't do it here | |
549 * because we don't necessarily have the tRNS chunk yet. | |
550 */ | |
551 void PNGAPI | |
552 png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) | |
553 { | 806 { |
554 png_debug(1, "in png_set_gamma"); | 807 png_debug(1, "in png_set_gamma_fixed"); |
555 | 808 |
556 if (png_ptr == NULL) | 809 if (png_rtran_ok(png_ptr, 0) == 0) |
557 return; | 810 return; |
558 | 811 |
559 if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) || | 812 /* New in libpng-1.5.4 - reserve particular negative values as flags. */ |
560 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) || | 813 scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/); |
561 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) | 814 file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/); |
562 png_ptr->transformations |= PNG_GAMMA; | 815 |
563 png_ptr->gamma = (float)file_gamma; | 816 /* Checking the gamma values for being >0 was added in 1.5.4 along with the |
564 png_ptr->screen_gamma = (float)scrn_gamma; | 817 * premultiplied alpha support; this actually hides an undocumented feature |
| 818 * of the previous implementation which allowed gamma processing to be |
| 819 * disabled in background handling. There is no evidence (so far) that this |
| 820 * was being used; however, png_set_background itself accepted and must still |
| 821 * accept '0' for the gamma value it takes, because it isn't always used. |
| 822 * |
| 823 * Since this is an API change (albeit a very minor one that removes an |
| 824 * undocumented API feature) the following checks were only enabled in |
| 825 * libpng-1.6.0. |
| 826 */ |
| 827 if (file_gamma <= 0) |
| 828 png_error(png_ptr, "invalid file gamma in png_set_gamma"); |
| 829 |
| 830 if (scrn_gamma <= 0) |
| 831 png_error(png_ptr, "invalid screen gamma in png_set_gamma"); |
| 832 |
| 833 /* Set the gamma values unconditionally - this overrides the value in the PNG |
| 834 * file if a gAMA chunk was present. png_set_alpha_mode provides a |
| 835 * different, easier, way to default the file gamma. |
| 836 */ |
| 837 png_ptr->colorspace.gamma = file_gamma; |
| 838 png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; |
| 839 png_ptr->screen_gamma = scrn_gamma; |
565 } | 840 } |
566 #endif | 841 |
| 842 # ifdef PNG_FLOATING_POINT_SUPPORTED |
| 843 void PNGAPI |
| 844 png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma) |
| 845 { |
| 846 png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma), |
| 847 convert_gamma_value(png_ptr, file_gamma)); |
| 848 } |
| 849 # endif /* FLOATING_POINT */ |
| 850 #endif /* READ_GAMMA */ |
567 | 851 |
568 #ifdef PNG_READ_EXPAND_SUPPORTED | 852 #ifdef PNG_READ_EXPAND_SUPPORTED |
569 /* Expand paletted images to RGB, expand grayscale images of | 853 /* Expand paletted images to RGB, expand grayscale images of |
570 * less than 8-bit depth to 8-bit depth, and expand tRNS chunks | 854 * less than 8-bit depth to 8-bit depth, and expand tRNS chunks |
571 * to alpha channels. | 855 * to alpha channels. |
572 */ | 856 */ |
573 void PNGAPI | 857 void PNGAPI |
574 png_set_expand(png_structp png_ptr) | 858 png_set_expand(png_structrp png_ptr) |
575 { | 859 { |
576 png_debug(1, "in png_set_expand"); | 860 png_debug(1, "in png_set_expand"); |
577 | 861 |
578 if (png_ptr == NULL) | 862 if (png_rtran_ok(png_ptr, 0) == 0) |
579 return; | 863 return; |
580 | 864 |
581 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); | 865 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
582 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | |
583 } | 866 } |
584 | 867 |
585 /* GRR 19990627: the following three functions currently are identical | 868 /* GRR 19990627: the following three functions currently are identical |
586 * to png_set_expand(). However, it is entirely reasonable that someone | 869 * to png_set_expand(). However, it is entirely reasonable that someone |
587 * might wish to expand an indexed image to RGB but *not* expand a single, | 870 * might wish to expand an indexed image to RGB but *not* expand a single, |
588 * fully transparent palette entry to a full alpha channel--perhaps instead | 871 * fully transparent palette entry to a full alpha channel--perhaps instead |
589 * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace | 872 * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace |
590 * the transparent color with a particular RGB value, or drop tRNS entirely. | 873 * the transparent color with a particular RGB value, or drop tRNS entirely. |
591 * IOW, a future version of the library may make the transformations flag | 874 * IOW, a future version of the library may make the transformations flag |
592 * a bit more fine-grained, with separate bits for each of these three | 875 * a bit more fine-grained, with separate bits for each of these three |
593 * functions. | 876 * functions. |
594 * | 877 * |
595 * More to the point, these functions make it obvious what libpng will be | 878 * More to the point, these functions make it obvious what libpng will be |
596 * doing, whereas "expand" can (and does) mean any number of things. | 879 * doing, whereas "expand" can (and does) mean any number of things. |
597 * | 880 * |
598 * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified | 881 * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified |
599 * to expand only the sample depth but not to expand the tRNS to alpha | 882 * to expand only the sample depth but not to expand the tRNS to alpha |
600 * and its name was changed to png_set_expand_gray_1_2_4_to_8(). | 883 * and its name was changed to png_set_expand_gray_1_2_4_to_8(). |
601 */ | 884 */ |
602 | 885 |
603 /* Expand paletted images to RGB. */ | 886 /* Expand paletted images to RGB. */ |
604 void PNGAPI | 887 void PNGAPI |
605 png_set_palette_to_rgb(png_structp png_ptr) | 888 png_set_palette_to_rgb(png_structrp png_ptr) |
606 { | 889 { |
607 png_debug(1, "in png_set_palette_to_rgb"); | 890 png_debug(1, "in png_set_palette_to_rgb"); |
608 | 891 |
609 if (png_ptr == NULL) | 892 if (png_rtran_ok(png_ptr, 0) == 0) |
610 return; | 893 return; |
611 | 894 |
612 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); | 895 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
613 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | 896 } |
614 } | 897 |
615 | |
616 #ifndef PNG_1_0_X | |
617 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ | 898 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
618 void PNGAPI | 899 void PNGAPI |
619 png_set_expand_gray_1_2_4_to_8(png_structp png_ptr) | 900 png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr) |
620 { | 901 { |
621 png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); | 902 png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); |
622 | 903 |
623 if (png_ptr == NULL) | 904 if (png_rtran_ok(png_ptr, 0) == 0) |
624 return; | 905 return; |
625 | 906 |
626 png_ptr->transformations |= PNG_EXPAND; | 907 png_ptr->transformations |= PNG_EXPAND; |
627 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | 908 } |
628 } | |
629 #endif | |
630 | |
631 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) | |
632 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ | |
633 /* Deprecated as of libpng-1.2.9 */ | |
634 void PNGAPI | |
635 png_set_gray_1_2_4_to_8(png_structp png_ptr) | |
636 { | |
637 png_debug(1, "in png_set_gray_1_2_4_to_8"); | |
638 | |
639 if (png_ptr == NULL) | |
640 return; | |
641 | |
642 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); | |
643 } | |
644 #endif | |
645 | |
646 | 909 |
647 /* Expand tRNS chunks to alpha channels. */ | 910 /* Expand tRNS chunks to alpha channels. */ |
648 void PNGAPI | 911 void PNGAPI |
649 png_set_tRNS_to_alpha(png_structp png_ptr) | 912 png_set_tRNS_to_alpha(png_structrp png_ptr) |
650 { | 913 { |
651 png_debug(1, "in png_set_tRNS_to_alpha"); | 914 png_debug(1, "in png_set_tRNS_to_alpha"); |
652 | 915 |
| 916 if (png_rtran_ok(png_ptr, 0) == 0) |
| 917 return; |
| 918 |
653 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); | 919 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
654 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | 920 } |
655 } | 921 #endif /* READ_EXPAND */ |
656 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ | 922 |
| 923 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
| 924 /* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise |
| 925 * it may not work correctly.) |
| 926 */ |
| 927 void PNGAPI |
| 928 png_set_expand_16(png_structrp png_ptr) |
| 929 { |
| 930 png_debug(1, "in png_set_expand_16"); |
| 931 |
| 932 if (png_rtran_ok(png_ptr, 0) == 0) |
| 933 return; |
| 934 |
| 935 png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS); |
| 936 } |
| 937 #endif |
657 | 938 |
658 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | 939 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
659 void PNGAPI | 940 void PNGAPI |
660 png_set_gray_to_rgb(png_structp png_ptr) | 941 png_set_gray_to_rgb(png_structrp png_ptr) |
661 { | 942 { |
662 png_debug(1, "in png_set_gray_to_rgb"); | 943 png_debug(1, "in png_set_gray_to_rgb"); |
663 | 944 |
| 945 if (png_rtran_ok(png_ptr, 0) == 0) |
| 946 return; |
| 947 |
| 948 /* Because rgb must be 8 bits or more: */ |
| 949 png_set_expand_gray_1_2_4_to_8(png_ptr); |
664 png_ptr->transformations |= PNG_GRAY_TO_RGB; | 950 png_ptr->transformations |= PNG_GRAY_TO_RGB; |
665 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; | |
666 } | 951 } |
667 #endif | 952 #endif |
668 | 953 |
669 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | 954 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
| 955 void PNGFAPI |
| 956 png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action, |
| 957 png_fixed_point red, png_fixed_point green) |
| 958 { |
| 959 png_debug(1, "in png_set_rgb_to_gray"); |
| 960 |
| 961 /* Need the IHDR here because of the check on color_type below. */ |
| 962 /* TODO: fix this */ |
| 963 if (png_rtran_ok(png_ptr, 1) == 0) |
| 964 return; |
| 965 |
| 966 switch (error_action) |
| 967 { |
| 968 case PNG_ERROR_ACTION_NONE: |
| 969 png_ptr->transformations |= PNG_RGB_TO_GRAY; |
| 970 break; |
| 971 |
| 972 case PNG_ERROR_ACTION_WARN: |
| 973 png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; |
| 974 break; |
| 975 |
| 976 case PNG_ERROR_ACTION_ERROR: |
| 977 png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; |
| 978 break; |
| 979 |
| 980 default: |
| 981 png_error(png_ptr, "invalid error action to rgb_to_gray"); |
| 982 } |
| 983 |
| 984 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 985 #ifdef PNG_READ_EXPAND_SUPPORTED |
| 986 png_ptr->transformations |= PNG_EXPAND; |
| 987 #else |
| 988 { |
| 989 /* Make this an error in 1.6 because otherwise the application may assume |
| 990 * that it just worked and get a memory overwrite. |
| 991 */ |
| 992 png_error(png_ptr, |
| 993 "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED"); |
| 994 |
| 995 /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */ |
| 996 } |
| 997 #endif |
| 998 { |
| 999 if (red >= 0 && green >= 0 && red + green <= PNG_FP_1) |
| 1000 { |
| 1001 png_uint_16 red_int, green_int; |
| 1002 |
| 1003 /* NOTE: this calculation does not round, but this behavior is retained |
| 1004 * for consistency; the inaccuracy is very small. The code here always |
| 1005 * overwrites the coefficients, regardless of whether they have been |
| 1006 * defaulted or set already. |
| 1007 */ |
| 1008 red_int = (png_uint_16)(((png_uint_32)red*32768)/100000); |
| 1009 green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); |
| 1010 |
| 1011 png_ptr->rgb_to_gray_red_coeff = red_int; |
| 1012 png_ptr->rgb_to_gray_green_coeff = green_int; |
| 1013 png_ptr->rgb_to_gray_coefficients_set = 1; |
| 1014 } |
| 1015 |
| 1016 else |
| 1017 { |
| 1018 if (red >= 0 && green >= 0) |
| 1019 png_app_warning(png_ptr, |
| 1020 "ignoring out of range rgb_to_gray coefficients"); |
| 1021 |
| 1022 /* Use the defaults, from the cHRM chunk if set, else the historical |
| 1023 * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See |
| 1024 * png_do_rgb_to_gray for more discussion of the values. In this case |
| 1025 * the coefficients are not marked as 'set' and are not overwritten if |
| 1026 * something has already provided a default. |
| 1027 */ |
| 1028 if (png_ptr->rgb_to_gray_red_coeff == 0 && |
| 1029 png_ptr->rgb_to_gray_green_coeff == 0) |
| 1030 { |
| 1031 png_ptr->rgb_to_gray_red_coeff = 6968; |
| 1032 png_ptr->rgb_to_gray_green_coeff = 23434; |
| 1033 /* png_ptr->rgb_to_gray_blue_coeff = 2366; */ |
| 1034 } |
| 1035 } |
| 1036 } |
| 1037 } |
| 1038 |
670 #ifdef PNG_FLOATING_POINT_SUPPORTED | 1039 #ifdef PNG_FLOATING_POINT_SUPPORTED |
671 /* Convert a RGB image to a grayscale of the same width. This allows us, | 1040 /* Convert a RGB image to a grayscale of the same width. This allows us, |
672 * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. | 1041 * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. |
673 */ | 1042 */ |
674 | 1043 |
675 void PNGAPI | 1044 void PNGAPI |
676 png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, | 1045 png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red, |
677 double green) | 1046 double green) |
678 { | 1047 { |
679 int red_fixed, green_fixed; | 1048 png_set_rgb_to_gray_fixed(png_ptr, error_action, |
680 if (png_ptr == NULL) | 1049 png_fixed(png_ptr, red, "rgb to gray red coefficient"), |
681 return; | 1050 png_fixed(png_ptr, green, "rgb to gray green coefficient")); |
682 if (red > 21474.83647 || red < -21474.83648 || | 1051 } |
683 green > 21474.83647 || green < -21474.83648) | 1052 #endif /* FLOATING POINT */ |
684 { | 1053 |
685 png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); | 1054 #endif /* RGB_TO_GRAY */ |
686 red_fixed = -1; | |
687 green_fixed = -1; | |
688 } | |
689 else | |
690 { | |
691 red_fixed = (int)((float)red*100000.0 + 0.5); | |
692 green_fixed = (int)((float)green*100000.0 + 0.5); | |
693 } | |
694 png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed); | |
695 } | |
696 #endif | |
697 | |
698 void PNGAPI | |
699 png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, | |
700 png_fixed_point red, png_fixed_point green) | |
701 { | |
702 png_debug(1, "in png_set_rgb_to_gray"); | |
703 | |
704 if (png_ptr == NULL) | |
705 return; | |
706 | |
707 switch(error_action) | |
708 { | |
709 case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY; | |
710 break; | |
711 | |
712 case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; | |
713 break; | |
714 | |
715 case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; | |
716 } | |
717 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
718 #ifdef PNG_READ_EXPAND_SUPPORTED | |
719 png_ptr->transformations |= PNG_EXPAND; | |
720 #else | |
721 { | |
722 png_warning(png_ptr, | |
723 "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED."); | |
724 png_ptr->transformations &= ~PNG_RGB_TO_GRAY; | |
725 } | |
726 #endif | |
727 { | |
728 png_uint_16 red_int, green_int; | |
729 if (red < 0 || green < 0) | |
730 { | |
731 red_int = 6968; /* .212671 * 32768 + .5 */ | |
732 green_int = 23434; /* .715160 * 32768 + .5 */ | |
733 } | |
734 else if (red + green < 100000L) | |
735 { | |
736 red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); | |
737 green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); | |
738 } | |
739 else | |
740 { | |
741 png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); | |
742 red_int = 6968; | |
743 green_int = 23434; | |
744 } | |
745 png_ptr->rgb_to_gray_red_coeff = red_int; | |
746 png_ptr->rgb_to_gray_green_coeff = green_int; | |
747 png_ptr->rgb_to_gray_blue_coeff = | |
748 (png_uint_16)(32768 - red_int - green_int); | |
749 } | |
750 } | |
751 #endif | |
752 | 1055 |
753 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ | 1056 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ |
754 defined(PNG_LEGACY_SUPPORTED) || \ | |
755 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) | 1057 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) |
756 void PNGAPI | 1058 void PNGAPI |
757 png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr | 1059 png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr |
758 read_user_transform_fn) | 1060 read_user_transform_fn) |
759 { | 1061 { |
760 png_debug(1, "in png_set_read_user_transform_fn"); | 1062 png_debug(1, "in png_set_read_user_transform_fn"); |
761 | 1063 |
762 if (png_ptr == NULL) | |
763 return; | |
764 | |
765 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED | 1064 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED |
766 png_ptr->transformations |= PNG_USER_TRANSFORM; | 1065 png_ptr->transformations |= PNG_USER_TRANSFORM; |
767 png_ptr->read_user_transform_fn = read_user_transform_fn; | 1066 png_ptr->read_user_transform_fn = read_user_transform_fn; |
768 #endif | 1067 #endif |
769 #ifdef PNG_LEGACY_SUPPORTED | 1068 } |
770 if (read_user_transform_fn) | 1069 #endif |
771 png_warning(png_ptr, | 1070 |
772 "This version of libpng does not support user transforms"); | 1071 #ifdef PNG_READ_TRANSFORMS_SUPPORTED |
773 #endif | 1072 #ifdef PNG_READ_GAMMA_SUPPORTED |
| 1073 /* In the case of gamma transformations only do transformations on images where |
| 1074 * the [file] gamma and screen_gamma are not close reciprocals, otherwise it |
| 1075 * slows things down slightly, and also needlessly introduces small errors. |
| 1076 */ |
| 1077 static int /* PRIVATE */ |
| 1078 png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma) |
| 1079 { |
| 1080 /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma |
| 1081 * correction as a difference of the overall transform from 1.0 |
| 1082 * |
| 1083 * We want to compare the threshold with s*f - 1, if we get |
| 1084 * overflow here it is because of wacky gamma values so we |
| 1085 * turn on processing anyway. |
| 1086 */ |
| 1087 png_fixed_point gtest; |
| 1088 return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) || |
| 1089 png_gamma_significant(gtest); |
774 } | 1090 } |
775 #endif | 1091 #endif |
776 | 1092 |
777 /* Initialize everything needed for the read. This includes modifying | 1093 /* Initialize everything needed for the read. This includes modifying |
778 * the palette. | 1094 * the palette. |
779 */ | 1095 */ |
| 1096 |
| 1097 /* For the moment 'png_init_palette_transformations' and |
| 1098 * 'png_init_rgb_transformations' only do some flag canceling optimizations. |
| 1099 * The intent is that these two routines should have palette or rgb operations |
| 1100 * extracted from 'png_init_read_transformations'. |
| 1101 */ |
| 1102 static void /* PRIVATE */ |
| 1103 png_init_palette_transformations(png_structrp png_ptr) |
| 1104 { |
| 1105 /* Called to handle the (input) palette case. In png_do_read_transformations |
| 1106 * the first step is to expand the palette if requested, so this code must |
| 1107 * take care to only make changes that are invariant with respect to the |
| 1108 * palette expansion, or only do them if there is no expansion. |
| 1109 * |
| 1110 * STRIP_ALPHA has already been handled in the caller (by setting num_trans |
| 1111 * to 0.) |
| 1112 */ |
| 1113 int input_has_alpha = 0; |
| 1114 int input_has_transparency = 0; |
| 1115 |
| 1116 if (png_ptr->num_trans > 0) |
| 1117 { |
| 1118 int i; |
| 1119 |
| 1120 /* Ignore if all the entries are opaque (unlikely!) */ |
| 1121 for (i=0; i<png_ptr->num_trans; ++i) |
| 1122 { |
| 1123 if (png_ptr->trans_alpha[i] == 255) |
| 1124 continue; |
| 1125 else if (png_ptr->trans_alpha[i] == 0) |
| 1126 input_has_transparency = 1; |
| 1127 else |
| 1128 { |
| 1129 input_has_transparency = 1; |
| 1130 input_has_alpha = 1; |
| 1131 break; |
| 1132 } |
| 1133 } |
| 1134 } |
| 1135 |
| 1136 /* If no alpha we can optimize. */ |
| 1137 if (input_has_alpha == 0) |
| 1138 { |
| 1139 /* Any alpha means background and associative alpha processing is |
| 1140 * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA |
| 1141 * and ENCODE_ALPHA are irrelevant. |
| 1142 */ |
| 1143 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
| 1144 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
| 1145 |
| 1146 if (input_has_transparency == 0) |
| 1147 png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); |
| 1148 } |
| 1149 |
| 1150 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 1151 /* png_set_background handling - deals with the complexity of whether the |
| 1152 * background color is in the file format or the screen format in the case |
| 1153 * where an 'expand' will happen. |
| 1154 */ |
| 1155 |
| 1156 /* The following code cannot be entered in the alpha pre-multiplication case |
| 1157 * because PNG_BACKGROUND_EXPAND is cancelled below. |
| 1158 */ |
| 1159 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && |
| 1160 (png_ptr->transformations & PNG_EXPAND) != 0) |
| 1161 { |
| 1162 { |
| 1163 png_ptr->background.red = |
| 1164 png_ptr->palette[png_ptr->background.index].red; |
| 1165 png_ptr->background.green = |
| 1166 png_ptr->palette[png_ptr->background.index].green; |
| 1167 png_ptr->background.blue = |
| 1168 png_ptr->palette[png_ptr->background.index].blue; |
| 1169 |
| 1170 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
| 1171 if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) |
| 1172 { |
| 1173 if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) |
| 1174 { |
| 1175 /* Invert the alpha channel (in tRNS) unless the pixels are |
| 1176 * going to be expanded, in which case leave it for later |
| 1177 */ |
| 1178 int i, istop = png_ptr->num_trans; |
| 1179 |
| 1180 for (i=0; i<istop; i++) |
| 1181 png_ptr->trans_alpha[i] = (png_byte)(255 - |
| 1182 png_ptr->trans_alpha[i]); |
| 1183 } |
| 1184 } |
| 1185 #endif /* READ_INVERT_ALPHA */ |
| 1186 } |
| 1187 } /* background expand and (therefore) no alpha association. */ |
| 1188 #endif /* READ_EXPAND && READ_BACKGROUND */ |
| 1189 } |
| 1190 |
| 1191 static void /* PRIVATE */ |
| 1192 png_init_rgb_transformations(png_structrp png_ptr) |
| 1193 { |
| 1194 /* Added to libpng-1.5.4: check the color type to determine whether there |
| 1195 * is any alpha or transparency in the image and simply cancel the |
| 1196 * background and alpha mode stuff if there isn't. |
| 1197 */ |
| 1198 int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0; |
| 1199 int input_has_transparency = png_ptr->num_trans > 0; |
| 1200 |
| 1201 /* If no alpha we can optimize. */ |
| 1202 if (input_has_alpha == 0) |
| 1203 { |
| 1204 /* Any alpha means background and associative alpha processing is |
| 1205 * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA |
| 1206 * and ENCODE_ALPHA are irrelevant. |
| 1207 */ |
| 1208 # ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
| 1209 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
| 1210 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
| 1211 # endif |
| 1212 |
| 1213 if (input_has_transparency == 0) |
| 1214 png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND); |
| 1215 } |
| 1216 |
| 1217 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 1218 /* png_set_background handling - deals with the complexity of whether the |
| 1219 * background color is in the file format or the screen format in the case |
| 1220 * where an 'expand' will happen. |
| 1221 */ |
| 1222 |
| 1223 /* The following code cannot be entered in the alpha pre-multiplication case |
| 1224 * because PNG_BACKGROUND_EXPAND is cancelled below. |
| 1225 */ |
| 1226 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 && |
| 1227 (png_ptr->transformations & PNG_EXPAND) != 0 && |
| 1228 (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) |
| 1229 /* i.e., GRAY or GRAY_ALPHA */ |
| 1230 { |
| 1231 { |
| 1232 /* Expand background and tRNS chunks */ |
| 1233 int gray = png_ptr->background.gray; |
| 1234 int trans_gray = png_ptr->trans_color.gray; |
| 1235 |
| 1236 switch (png_ptr->bit_depth) |
| 1237 { |
| 1238 case 1: |
| 1239 gray *= 0xff; |
| 1240 trans_gray *= 0xff; |
| 1241 break; |
| 1242 |
| 1243 case 2: |
| 1244 gray *= 0x55; |
| 1245 trans_gray *= 0x55; |
| 1246 break; |
| 1247 |
| 1248 case 4: |
| 1249 gray *= 0x11; |
| 1250 trans_gray *= 0x11; |
| 1251 break; |
| 1252 |
| 1253 default: |
| 1254 |
| 1255 case 8: |
| 1256 /* FALL THROUGH (Already 8 bits) */ |
| 1257 |
| 1258 case 16: |
| 1259 /* Already a full 16 bits */ |
| 1260 break; |
| 1261 } |
| 1262 |
| 1263 png_ptr->background.red = png_ptr->background.green = |
| 1264 png_ptr->background.blue = (png_uint_16)gray; |
| 1265 |
| 1266 if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0) |
| 1267 { |
| 1268 png_ptr->trans_color.red = png_ptr->trans_color.green = |
| 1269 png_ptr->trans_color.blue = (png_uint_16)trans_gray; |
| 1270 } |
| 1271 } |
| 1272 } /* background expand and (therefore) no alpha association. */ |
| 1273 #endif /* READ_EXPAND && READ_BACKGROUND */ |
| 1274 } |
| 1275 |
780 void /* PRIVATE */ | 1276 void /* PRIVATE */ |
781 png_init_read_transformations(png_structp png_ptr) | 1277 png_init_read_transformations(png_structrp png_ptr) |
782 { | 1278 { |
783 png_debug(1, "in png_init_read_transformations"); | 1279 png_debug(1, "in png_init_read_transformations"); |
784 | 1280 |
785 #ifdef PNG_USELESS_TESTS_SUPPORTED | 1281 /* This internal function is called from png_read_start_row in pngrutil.c |
786 if (png_ptr != NULL) | 1282 * and it is called before the 'rowbytes' calculation is done, so the code |
787 #endif | 1283 * in here can change or update the transformations flags. |
788 { | 1284 * |
789 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ | 1285 * First do updates that do not depend on the details of the PNG image data |
790 defined(PNG_READ_SHIFT_SUPPORTED) || \ | 1286 * being processed. |
791 defined(PNG_READ_GAMMA_SUPPORTED) | 1287 */ |
792 int color_type = png_ptr->color_type; | 1288 |
793 #endif | 1289 #ifdef PNG_READ_GAMMA_SUPPORTED |
794 | 1290 /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds |
| 1291 * png_set_alpha_mode and this is another source for a default file gamma so |
| 1292 * the test needs to be performed later - here. In addition prior to 1.5.4 |
| 1293 * the tests were repeated for the PALETTE color type here - this is no |
| 1294 * longer necessary (and doesn't seem to have been necessary before.) |
| 1295 */ |
| 1296 { |
| 1297 /* The following temporary indicates if overall gamma correction is |
| 1298 * required. |
| 1299 */ |
| 1300 int gamma_correction = 0; |
| 1301 |
| 1302 if (png_ptr->colorspace.gamma != 0) /* has been set */ |
| 1303 { |
| 1304 if (png_ptr->screen_gamma != 0) /* screen set too */ |
| 1305 gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma, |
| 1306 png_ptr->screen_gamma); |
| 1307 |
| 1308 else |
| 1309 /* Assume the output matches the input; a long time default behavior |
| 1310 * of libpng, although the standard has nothing to say about this. |
| 1311 */ |
| 1312 png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma); |
| 1313 } |
| 1314 |
| 1315 else if (png_ptr->screen_gamma != 0) |
| 1316 /* The converse - assume the file matches the screen, note that this |
| 1317 * perhaps undesireable default can (from 1.5.4) be changed by calling |
| 1318 * png_set_alpha_mode (even if the alpha handling mode isn't required |
| 1319 * or isn't changed from the default.) |
| 1320 */ |
| 1321 png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma); |
| 1322 |
| 1323 else /* neither are set */ |
| 1324 /* Just in case the following prevents any processing - file and screen |
| 1325 * are both assumed to be linear and there is no way to introduce a |
| 1326 * third gamma value other than png_set_background with 'UNIQUE', and, |
| 1327 * prior to 1.5.4 |
| 1328 */ |
| 1329 png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1; |
| 1330 |
| 1331 /* We have a gamma value now. */ |
| 1332 png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA; |
| 1333 |
| 1334 /* Now turn the gamma transformation on or off as appropriate. Notice |
| 1335 * that PNG_GAMMA just refers to the file->screen correction. Alpha |
| 1336 * composition may independently cause gamma correction because it needs |
| 1337 * linear data (e.g. if the file has a gAMA chunk but the screen gamma |
| 1338 * hasn't been specified.) In any case this flag may get turned off in |
| 1339 * the code immediately below if the transform can be handled outside the |
| 1340 * row loop. |
| 1341 */ |
| 1342 if (gamma_correction != 0) |
| 1343 png_ptr->transformations |= PNG_GAMMA; |
| 1344 |
| 1345 else |
| 1346 png_ptr->transformations &= ~PNG_GAMMA; |
| 1347 } |
| 1348 #endif |
| 1349 |
| 1350 /* Certain transformations have the effect of preventing other |
| 1351 * transformations that happen afterward in png_do_read_transformations; |
| 1352 * resolve the interdependencies here. From the code of |
| 1353 * png_do_read_transformations the order is: |
| 1354 * |
| 1355 * 1) PNG_EXPAND (including PNG_EXPAND_tRNS) |
| 1356 * 2) PNG_STRIP_ALPHA (if no compose) |
| 1357 * 3) PNG_RGB_TO_GRAY |
| 1358 * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY |
| 1359 * 5) PNG_COMPOSE |
| 1360 * 6) PNG_GAMMA |
| 1361 * 7) PNG_STRIP_ALPHA (if compose) |
| 1362 * 8) PNG_ENCODE_ALPHA |
| 1363 * 9) PNG_SCALE_16_TO_8 |
| 1364 * 10) PNG_16_TO_8 |
| 1365 * 11) PNG_QUANTIZE (converts to palette) |
| 1366 * 12) PNG_EXPAND_16 |
| 1367 * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY |
| 1368 * 14) PNG_INVERT_MONO |
| 1369 * 15) PNG_INVERT_ALPHA |
| 1370 * 16) PNG_SHIFT |
| 1371 * 17) PNG_PACK |
| 1372 * 18) PNG_BGR |
| 1373 * 19) PNG_PACKSWAP |
| 1374 * 20) PNG_FILLER (includes PNG_ADD_ALPHA) |
| 1375 * 21) PNG_SWAP_ALPHA |
| 1376 * 22) PNG_SWAP_BYTES |
| 1377 * 23) PNG_USER_TRANSFORM [must be last] |
| 1378 */ |
| 1379 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
| 1380 if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && |
| 1381 (png_ptr->transformations & PNG_COMPOSE) == 0) |
| 1382 { |
| 1383 /* Stripping the alpha channel happens immediately after the 'expand' |
| 1384 * transformations, before all other transformation, so it cancels out |
| 1385 * the alpha handling. It has the side effect negating the effect of |
| 1386 * PNG_EXPAND_tRNS too: |
| 1387 */ |
| 1388 png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA | |
| 1389 PNG_EXPAND_tRNS); |
| 1390 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
| 1391 |
| 1392 /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen |
| 1393 * so transparency information would remain just so long as it wasn't |
| 1394 * expanded. This produces unexpected API changes if the set of things |
| 1395 * that do PNG_EXPAND_tRNS changes (perfectly possible given the |
| 1396 * documentation - which says ask for what you want, accept what you |
| 1397 * get.) This makes the behavior consistent from 1.5.4: |
| 1398 */ |
| 1399 png_ptr->num_trans = 0; |
| 1400 } |
| 1401 #endif /* STRIP_ALPHA supported, no COMPOSE */ |
| 1402 |
| 1403 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
| 1404 /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA |
| 1405 * settings will have no effect. |
| 1406 */ |
| 1407 if (png_gamma_significant(png_ptr->screen_gamma) == 0) |
| 1408 { |
| 1409 png_ptr->transformations &= ~PNG_ENCODE_ALPHA; |
| 1410 png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA; |
| 1411 } |
| 1412 #endif |
| 1413 |
| 1414 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
| 1415 /* Make sure the coefficients for the rgb to gray conversion are set |
| 1416 * appropriately. |
| 1417 */ |
| 1418 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) |
| 1419 png_colorspace_set_rgb_coefficients(png_ptr); |
| 1420 #endif |
| 1421 |
| 1422 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
795 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) | 1423 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
796 | 1424 /* Detect gray background and attempt to enable optimization for |
797 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | 1425 * gray --> RGB case. |
798 /* Detect gray background and attempt to enable optimization | |
799 * for gray --> RGB case | |
800 * | 1426 * |
801 * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or | 1427 * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or |
802 * RGB_ALPHA (in which case need_expand is superfluous anyway), the | 1428 * RGB_ALPHA (in which case need_expand is superfluous anyway), the |
803 * background color might actually be gray yet not be flagged as such. | 1429 * background color might actually be gray yet not be flagged as such. |
804 * This is not a problem for the current code, which uses | 1430 * This is not a problem for the current code, which uses |
805 * PNG_BACKGROUND_IS_GRAY only to decide when to do the | 1431 * PNG_BACKGROUND_IS_GRAY only to decide when to do the |
806 * png_do_gray_to_rgb() transformation. | 1432 * png_do_gray_to_rgb() transformation. |
807 */ | 1433 * |
808 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && | 1434 * TODO: this code needs to be revised to avoid the complexity and |
809 !(color_type & PNG_COLOR_MASK_COLOR)) | 1435 * interdependencies. The color type of the background should be recorded in |
810 { | 1436 * png_set_background, along with the bit depth, then the code has a record |
811 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; | 1437 * of exactly what color space the background is currently in. |
812 } else if ((png_ptr->transformations & PNG_BACKGROUND) && | 1438 */ |
813 !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && | 1439 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0) |
814 (png_ptr->transformations & PNG_GRAY_TO_RGB) && | 1440 { |
815 png_ptr->background.red == png_ptr->background.green && | 1441 /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if |
816 png_ptr->background.red == png_ptr->background.blue) | 1442 * the file was grayscale the background value is gray. |
817 { | 1443 */ |
818 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; | 1444 if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) |
819 png_ptr->background.gray = png_ptr->background.red; | 1445 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
820 } | 1446 } |
821 #endif | 1447 |
822 | 1448 else if ((png_ptr->transformations & PNG_COMPOSE) != 0) |
823 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && | 1449 { |
824 (png_ptr->transformations & PNG_EXPAND)) | 1450 /* PNG_COMPOSE: png_set_background was called with need_expand false, |
825 { | 1451 * so the color is in the color space of the output or png_set_alpha_mode |
826 if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */ | 1452 * was called and the color is black. Ignore RGB_TO_GRAY because that |
| 1453 * happens before GRAY_TO_RGB. |
| 1454 */ |
| 1455 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) |
827 { | 1456 { |
828 /* Expand background and tRNS chunks */ | 1457 if (png_ptr->background.red == png_ptr->background.green && |
829 switch (png_ptr->bit_depth) | 1458 png_ptr->background.red == png_ptr->background.blue) |
830 { | 1459 { |
831 case 1: | 1460 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
832 png_ptr->background.gray *= (png_uint_16)0xff; | 1461 png_ptr->background.gray = png_ptr->background.red; |
833 png_ptr->background.red = png_ptr->background.green | |
834 = png_ptr->background.blue = png_ptr->background.gray; | |
835 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) | |
836 { | |
837 png_ptr->trans_values.gray *= (png_uint_16)0xff; | |
838 png_ptr->trans_values.red = png_ptr->trans_values.green | |
839 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; | |
840 } | |
841 break; | |
842 | |
843 case 2: | |
844 png_ptr->background.gray *= (png_uint_16)0x55; | |
845 png_ptr->background.red = png_ptr->background.green | |
846 = png_ptr->background.blue = png_ptr->background.gray; | |
847 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) | |
848 { | |
849 png_ptr->trans_values.gray *= (png_uint_16)0x55; | |
850 png_ptr->trans_values.red = png_ptr->trans_values.green | |
851 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; | |
852 } | |
853 break; | |
854 | |
855 case 4: | |
856 png_ptr->background.gray *= (png_uint_16)0x11; | |
857 png_ptr->background.red = png_ptr->background.green | |
858 = png_ptr->background.blue = png_ptr->background.gray; | |
859 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) | |
860 { | |
861 png_ptr->trans_values.gray *= (png_uint_16)0x11; | |
862 png_ptr->trans_values.red = png_ptr->trans_values.green | |
863 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; | |
864 } | |
865 break; | |
866 | |
867 case 8: | |
868 | |
869 case 16: | |
870 png_ptr->background.red = png_ptr->background.green | |
871 = png_ptr->background.blue = png_ptr->background.gray; | |
872 break; | |
873 } | 1462 } |
874 } | 1463 } |
875 else if (color_type == PNG_COLOR_TYPE_PALETTE) | 1464 } |
| 1465 #endif /* READ_EXPAND && READ_BACKGROUND */ |
| 1466 #endif /* READ_GRAY_TO_RGB */ |
| 1467 |
| 1468 /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations |
| 1469 * can be performed directly on the palette, and some (such as rgb to gray) |
| 1470 * can be optimized inside the palette. This is particularly true of the |
| 1471 * composite (background and alpha) stuff, which can be pretty much all done |
| 1472 * in the palette even if the result is expanded to RGB or gray afterward. |
| 1473 * |
| 1474 * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and |
| 1475 * earlier and the palette stuff is actually handled on the first row. This |
| 1476 * leads to the reported bug that the palette returned by png_get_PLTE is not |
| 1477 * updated. |
| 1478 */ |
| 1479 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 1480 png_init_palette_transformations(png_ptr); |
| 1481 |
| 1482 else |
| 1483 png_init_rgb_transformations(png_ptr); |
| 1484 |
| 1485 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
| 1486 defined(PNG_READ_EXPAND_16_SUPPORTED) |
| 1487 if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && |
| 1488 (png_ptr->transformations & PNG_COMPOSE) != 0 && |
| 1489 (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && |
| 1490 png_ptr->bit_depth != 16) |
| 1491 { |
| 1492 /* TODO: fix this. Because the expand_16 operation is after the compose |
| 1493 * handling the background color must be 8, not 16, bits deep, but the |
| 1494 * application will supply a 16-bit value so reduce it here. |
| 1495 * |
| 1496 * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at |
| 1497 * present, so that case is ok (until do_expand_16 is moved.) |
| 1498 * |
| 1499 * NOTE: this discards the low 16 bits of the user supplied background |
| 1500 * color, but until expand_16 works properly there is no choice! |
| 1501 */ |
| 1502 # define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x)) |
| 1503 CHOP(png_ptr->background.red); |
| 1504 CHOP(png_ptr->background.green); |
| 1505 CHOP(png_ptr->background.blue); |
| 1506 CHOP(png_ptr->background.gray); |
| 1507 # undef CHOP |
| 1508 } |
| 1509 #endif /* READ_BACKGROUND && READ_EXPAND_16 */ |
| 1510 |
| 1511 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
| 1512 (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ |
| 1513 defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) |
| 1514 if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 && |
| 1515 (png_ptr->transformations & PNG_COMPOSE) != 0 && |
| 1516 (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 && |
| 1517 png_ptr->bit_depth == 16) |
| 1518 { |
| 1519 /* On the other hand, if a 16-bit file is to be reduced to 8-bits per |
| 1520 * component this will also happen after PNG_COMPOSE and so the background |
| 1521 * color must be pre-expanded here. |
| 1522 * |
| 1523 * TODO: fix this too. |
| 1524 */ |
| 1525 png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); |
| 1526 png_ptr->background.green = |
| 1527 (png_uint_16)(png_ptr->background.green * 257); |
| 1528 png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); |
| 1529 png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); |
| 1530 } |
| 1531 #endif |
| 1532 |
| 1533 /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the |
| 1534 * background support (see the comments in scripts/pnglibconf.dfa), this |
| 1535 * allows pre-multiplication of the alpha channel to be implemented as |
| 1536 * compositing on black. This is probably sub-optimal and has been done in |
| 1537 * 1.5.4 betas simply to enable external critique and testing (i.e. to |
| 1538 * implement the new API quickly, without lots of internal changes.) |
| 1539 */ |
| 1540 |
| 1541 #ifdef PNG_READ_GAMMA_SUPPORTED |
| 1542 # ifdef PNG_READ_BACKGROUND_SUPPORTED |
| 1543 /* Includes ALPHA_MODE */ |
| 1544 png_ptr->background_1 = png_ptr->background; |
| 1545 # endif |
| 1546 |
| 1547 /* This needs to change - in the palette image case a whole set of tables are |
| 1548 * built when it would be quicker to just calculate the correct value for |
| 1549 * each palette entry directly. Also, the test is too tricky - why check |
| 1550 * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that |
| 1551 * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the |
| 1552 * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction |
| 1553 * the gamma tables will not be built even if composition is required on a |
| 1554 * gamma encoded value. |
| 1555 * |
| 1556 * In 1.5.4 this is addressed below by an additional check on the individual |
| 1557 * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the |
| 1558 * tables. |
| 1559 */ |
| 1560 if ((png_ptr->transformations & PNG_GAMMA) != 0 || |
| 1561 ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 && |
| 1562 (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || |
| 1563 png_gamma_significant(png_ptr->screen_gamma) != 0)) || |
| 1564 ((png_ptr->transformations & PNG_COMPOSE) != 0 && |
| 1565 (png_gamma_significant(png_ptr->colorspace.gamma) != 0 || |
| 1566 png_gamma_significant(png_ptr->screen_gamma) != 0 |
| 1567 # ifdef PNG_READ_BACKGROUND_SUPPORTED |
| 1568 || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE && |
| 1569 png_gamma_significant(png_ptr->background_gamma) != 0) |
| 1570 # endif |
| 1571 )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && |
| 1572 png_gamma_significant(png_ptr->screen_gamma) != 0)) |
| 1573 { |
| 1574 png_build_gamma_table(png_ptr, png_ptr->bit_depth); |
| 1575 |
| 1576 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
| 1577 if ((png_ptr->transformations & PNG_COMPOSE) != 0) |
876 { | 1578 { |
877 png_ptr->background.red = | 1579 /* Issue a warning about this combination: because RGB_TO_GRAY is |
878 png_ptr->palette[png_ptr->background.index].red; | 1580 * optimized to do the gamma transform if present yet do_background has |
879 png_ptr->background.green = | 1581 * to do the same thing if both options are set a |
880 png_ptr->palette[png_ptr->background.index].green; | 1582 * double-gamma-correction happens. This is true in all versions of |
881 png_ptr->background.blue = | 1583 * libpng to date. |
882 png_ptr->palette[png_ptr->background.index].blue; | 1584 */ |
883 | 1585 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) |
884 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED | 1586 png_warning(png_ptr, |
885 if (png_ptr->transformations & PNG_INVERT_ALPHA) | 1587 "libpng does not support gamma+background+rgb_to_gray"); |
886 { | 1588 |
887 #ifdef PNG_READ_EXPAND_SUPPORTED | 1589 if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0) |
888 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) | |
889 #endif | |
890 { | |
891 /* Invert the alpha channel (in tRNS) unless the pixels are | |
892 * going to be expanded, in which case leave it for later | |
893 */ | |
894 int i, istop; | |
895 istop=(int)png_ptr->num_trans; | |
896 for (i=0; i<istop; i++) | |
897 png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]); | |
898 } | |
899 } | |
900 #endif | |
901 | |
902 } | |
903 } | |
904 #endif | |
905 | |
906 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) | |
907 png_ptr->background_1 = png_ptr->background; | |
908 #endif | |
909 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) | |
910 | |
911 if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0) | |
912 && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0) | |
913 < PNG_GAMMA_THRESHOLD)) | |
914 { | |
915 int i, k; | |
916 k=0; | |
917 for (i=0; i<png_ptr->num_trans; i++) | |
918 { | |
919 if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff) | |
920 { | |
921 k=1; /* Partial transparency is present */ | |
922 break; | |
923 } | |
924 } | |
925 if (k == 0) | |
926 png_ptr->transformations &= ~PNG_GAMMA; | |
927 } | |
928 | |
929 if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) && | |
930 png_ptr->gamma != 0.0) | |
931 { | |
932 png_build_gamma_table(png_ptr); | |
933 | |
934 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
935 if (png_ptr->transformations & PNG_BACKGROUND) | |
936 { | |
937 if (color_type == PNG_COLOR_TYPE_PALETTE) | |
938 { | 1590 { |
939 /* Could skip if no transparency */ | 1591 /* We don't get to here unless there is a tRNS chunk with non-opaque |
| 1592 * entries - see the checking code at the start of this function. |
| 1593 */ |
940 png_color back, back_1; | 1594 png_color back, back_1; |
941 png_colorp palette = png_ptr->palette; | 1595 png_colorp palette = png_ptr->palette; |
942 int num_palette = png_ptr->num_palette; | 1596 int num_palette = png_ptr->num_palette; |
943 int i; | 1597 int i; |
944 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) | 1598 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
945 { | 1599 { |
| 1600 |
946 back.red = png_ptr->gamma_table[png_ptr->background.red]; | 1601 back.red = png_ptr->gamma_table[png_ptr->background.red]; |
947 back.green = png_ptr->gamma_table[png_ptr->background.green]; | 1602 back.green = png_ptr->gamma_table[png_ptr->background.green]; |
948 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; | 1603 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
949 | 1604 |
950 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; | 1605 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
951 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; | 1606 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
952 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; | 1607 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
953 } | 1608 } |
954 else | 1609 else |
955 { | 1610 { |
956 double g, gs; | 1611 png_fixed_point g, gs; |
957 | 1612 |
958 switch (png_ptr->background_gamma_type) | 1613 switch (png_ptr->background_gamma_type) |
959 { | 1614 { |
960 case PNG_BACKGROUND_GAMMA_SCREEN: | 1615 case PNG_BACKGROUND_GAMMA_SCREEN: |
961 g = (png_ptr->screen_gamma); | 1616 g = (png_ptr->screen_gamma); |
962 gs = 1.0; | 1617 gs = PNG_FP_1; |
963 break; | 1618 break; |
964 | 1619 |
965 case PNG_BACKGROUND_GAMMA_FILE: | 1620 case PNG_BACKGROUND_GAMMA_FILE: |
966 g = 1.0 / (png_ptr->gamma); | 1621 g = png_reciprocal(png_ptr->colorspace.gamma); |
967 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); | 1622 gs = png_reciprocal2(png_ptr->colorspace.gamma, |
| 1623 png_ptr->screen_gamma); |
968 break; | 1624 break; |
969 | 1625 |
970 case PNG_BACKGROUND_GAMMA_UNIQUE: | 1626 case PNG_BACKGROUND_GAMMA_UNIQUE: |
971 g = 1.0 / (png_ptr->background_gamma); | 1627 g = png_reciprocal(png_ptr->background_gamma); |
972 gs = 1.0 / (png_ptr->background_gamma * | 1628 gs = png_reciprocal2(png_ptr->background_gamma, |
973 png_ptr->screen_gamma); | 1629 png_ptr->screen_gamma); |
974 break; | 1630 break; |
975 default: | 1631 default: |
976 g = 1.0; /* back_1 */ | 1632 g = PNG_FP_1; /* back_1 */ |
977 gs = 1.0; /* back */ | 1633 gs = PNG_FP_1; /* back */ |
| 1634 break; |
978 } | 1635 } |
979 | 1636 |
980 if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD) | 1637 if (png_gamma_significant(gs) != 0) |
| 1638 { |
| 1639 back.red = png_gamma_8bit_correct(png_ptr->background.red, |
| 1640 gs); |
| 1641 back.green = png_gamma_8bit_correct(png_ptr->background.green, |
| 1642 gs); |
| 1643 back.blue = png_gamma_8bit_correct(png_ptr->background.blue, |
| 1644 gs); |
| 1645 } |
| 1646 |
| 1647 else |
981 { | 1648 { |
982 back.red = (png_byte)png_ptr->background.red; | 1649 back.red = (png_byte)png_ptr->background.red; |
983 back.green = (png_byte)png_ptr->background.green; | 1650 back.green = (png_byte)png_ptr->background.green; |
984 back.blue = (png_byte)png_ptr->background.blue; | 1651 back.blue = (png_byte)png_ptr->background.blue; |
985 } | 1652 } |
| 1653 |
| 1654 if (png_gamma_significant(g) != 0) |
| 1655 { |
| 1656 back_1.red = png_gamma_8bit_correct(png_ptr->background.red, |
| 1657 g); |
| 1658 back_1.green = png_gamma_8bit_correct( |
| 1659 png_ptr->background.green, g); |
| 1660 back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue, |
| 1661 g); |
| 1662 } |
| 1663 |
986 else | 1664 else |
987 { | 1665 { |
988 back.red = (png_byte)(pow( | 1666 back_1.red = (png_byte)png_ptr->background.red; |
989 (double)png_ptr->background.red/255, gs) * 255.0 + .5); | 1667 back_1.green = (png_byte)png_ptr->background.green; |
990 back.green = (png_byte)(pow( | 1668 back_1.blue = (png_byte)png_ptr->background.blue; |
991 (double)png_ptr->background.green/255, gs) * 255.0 | |
992 + .5); | |
993 back.blue = (png_byte)(pow( | |
994 (double)png_ptr->background.blue/255, gs) * 255.0 + .5); | |
995 } | 1669 } |
| 1670 } |
996 | 1671 |
997 back_1.red = (png_byte)(pow( | |
998 (double)png_ptr->background.red/255, g) * 255.0 + .5); | |
999 back_1.green = (png_byte)(pow( | |
1000 (double)png_ptr->background.green/255, g) * 255.0 + .5); | |
1001 back_1.blue = (png_byte)(pow( | |
1002 (double)png_ptr->background.blue/255, g) * 255.0 + .5); | |
1003 } | |
1004 for (i = 0; i < num_palette; i++) | 1672 for (i = 0; i < num_palette; i++) |
1005 { | 1673 { |
1006 if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff) | 1674 if (i < (int)png_ptr->num_trans && |
| 1675 png_ptr->trans_alpha[i] != 0xff) |
1007 { | 1676 { |
1008 if (png_ptr->trans[i] == 0) | 1677 if (png_ptr->trans_alpha[i] == 0) |
1009 { | 1678 { |
1010 palette[i] = back; | 1679 palette[i] = back; |
1011 } | 1680 } |
1012 else /* if (png_ptr->trans[i] != 0xff) */ | 1681 else /* if (png_ptr->trans_alpha[i] != 0xff) */ |
1013 { | 1682 { |
1014 png_byte v, w; | 1683 png_byte v, w; |
1015 | 1684 |
1016 v = png_ptr->gamma_to_1[palette[i].red]; | 1685 v = png_ptr->gamma_to_1[palette[i].red]; |
1017 png_composite(w, v, png_ptr->trans[i], back_1.red); | 1686 png_composite(w, v, png_ptr->trans_alpha[i], back_1.red); |
1018 palette[i].red = png_ptr->gamma_from_1[w]; | 1687 palette[i].red = png_ptr->gamma_from_1[w]; |
1019 | 1688 |
1020 v = png_ptr->gamma_to_1[palette[i].green]; | 1689 v = png_ptr->gamma_to_1[palette[i].green]; |
1021 png_composite(w, v, png_ptr->trans[i], back_1.green); | 1690 png_composite(w, v, png_ptr->trans_alpha[i], back_1.green); |
1022 palette[i].green = png_ptr->gamma_from_1[w]; | 1691 palette[i].green = png_ptr->gamma_from_1[w]; |
1023 | 1692 |
1024 v = png_ptr->gamma_to_1[palette[i].blue]; | 1693 v = png_ptr->gamma_to_1[palette[i].blue]; |
1025 png_composite(w, v, png_ptr->trans[i], back_1.blue); | 1694 png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue); |
1026 palette[i].blue = png_ptr->gamma_from_1[w]; | 1695 palette[i].blue = png_ptr->gamma_from_1[w]; |
1027 } | 1696 } |
1028 } | 1697 } |
1029 else | 1698 else |
1030 { | 1699 { |
1031 palette[i].red = png_ptr->gamma_table[palette[i].red]; | 1700 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
1032 palette[i].green = png_ptr->gamma_table[palette[i].green]; | 1701 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
1033 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; | 1702 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
1034 } | 1703 } |
1035 } | 1704 } |
1036 /* Prevent the transformations being done again, and make sure | 1705 |
1037 * that the now spurious alpha channel is stripped - the code | 1706 /* Prevent the transformations being done again. |
1038 * has just reduced background composition and gamma correction | 1707 * |
1039 * to a simple alpha channel strip. | 1708 * NOTE: this is highly dubious; it removes the transformations in |
| 1709 * place. This seems inconsistent with the general treatment of the |
| 1710 * transformations elsewhere. |
1040 */ | 1711 */ |
1041 png_ptr->transformations &= ~PNG_BACKGROUND; | 1712 png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA); |
1042 png_ptr->transformations &= ~PNG_GAMMA; | 1713 } /* color_type == PNG_COLOR_TYPE_PALETTE */ |
1043 png_ptr->transformations |= PNG_STRIP_ALPHA; | 1714 |
1044 } | |
1045 /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ | 1715 /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ |
1046 else | 1716 else /* color_type != PNG_COLOR_TYPE_PALETTE */ |
1047 /* color_type != PNG_COLOR_TYPE_PALETTE */ | |
1048 { | 1717 { |
1049 double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); | 1718 int gs_sig, g_sig; |
1050 double g = 1.0; | 1719 png_fixed_point g = PNG_FP_1; /* Correction to linear */ |
1051 double gs = 1.0; | 1720 png_fixed_point gs = PNG_FP_1; /* Correction to screen */ |
1052 | 1721 |
1053 switch (png_ptr->background_gamma_type) | 1722 switch (png_ptr->background_gamma_type) |
1054 { | 1723 { |
1055 case PNG_BACKGROUND_GAMMA_SCREEN: | 1724 case PNG_BACKGROUND_GAMMA_SCREEN: |
1056 g = (png_ptr->screen_gamma); | 1725 g = png_ptr->screen_gamma; |
1057 gs = 1.0; | 1726 /* gs = PNG_FP_1; */ |
1058 break; | 1727 break; |
1059 | 1728 |
1060 case PNG_BACKGROUND_GAMMA_FILE: | 1729 case PNG_BACKGROUND_GAMMA_FILE: |
1061 g = 1.0 / (png_ptr->gamma); | 1730 g = png_reciprocal(png_ptr->colorspace.gamma); |
1062 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); | 1731 gs = png_reciprocal2(png_ptr->colorspace.gamma, |
| 1732 png_ptr->screen_gamma); |
1063 break; | 1733 break; |
1064 | 1734 |
1065 case PNG_BACKGROUND_GAMMA_UNIQUE: | 1735 case PNG_BACKGROUND_GAMMA_UNIQUE: |
1066 g = 1.0 / (png_ptr->background_gamma); | 1736 g = png_reciprocal(png_ptr->background_gamma); |
1067 gs = 1.0 / (png_ptr->background_gamma * | 1737 gs = png_reciprocal2(png_ptr->background_gamma, |
1068 png_ptr->screen_gamma); | 1738 png_ptr->screen_gamma); |
1069 break; | 1739 break; |
| 1740 |
| 1741 default: |
| 1742 png_error(png_ptr, "invalid background gamma type"); |
1070 } | 1743 } |
1071 | 1744 |
1072 png_ptr->background_1.gray = (png_uint_16)(pow( | 1745 g_sig = png_gamma_significant(g); |
1073 (double)png_ptr->background.gray / m, g) * m + .5); | 1746 gs_sig = png_gamma_significant(gs); |
1074 png_ptr->background.gray = (png_uint_16)(pow( | 1747 |
1075 (double)png_ptr->background.gray / m, gs) * m + .5); | 1748 if (g_sig != 0) |
| 1749 png_ptr->background_1.gray = png_gamma_correct(png_ptr, |
| 1750 png_ptr->background.gray, g); |
| 1751 |
| 1752 if (gs_sig != 0) |
| 1753 png_ptr->background.gray = png_gamma_correct(png_ptr, |
| 1754 png_ptr->background.gray, gs); |
1076 | 1755 |
1077 if ((png_ptr->background.red != png_ptr->background.green) || | 1756 if ((png_ptr->background.red != png_ptr->background.green) || |
1078 (png_ptr->background.red != png_ptr->background.blue) || | 1757 (png_ptr->background.red != png_ptr->background.blue) || |
1079 (png_ptr->background.red != png_ptr->background.gray)) | 1758 (png_ptr->background.red != png_ptr->background.gray)) |
1080 { | 1759 { |
1081 /* RGB or RGBA with color background */ | 1760 /* RGB or RGBA with color background */ |
1082 png_ptr->background_1.red = (png_uint_16)(pow( | 1761 if (g_sig != 0) |
1083 (double)png_ptr->background.red / m, g) * m + .5); | 1762 { |
1084 png_ptr->background_1.green = (png_uint_16)(pow( | 1763 png_ptr->background_1.red = png_gamma_correct(png_ptr, |
1085 (double)png_ptr->background.green / m, g) * m + .5); | 1764 png_ptr->background.red, g); |
1086 png_ptr->background_1.blue = (png_uint_16)(pow( | 1765 |
1087 (double)png_ptr->background.blue / m, g) * m + .5); | 1766 png_ptr->background_1.green = png_gamma_correct(png_ptr, |
1088 png_ptr->background.red = (png_uint_16)(pow( | 1767 png_ptr->background.green, g); |
1089 (double)png_ptr->background.red / m, gs) * m + .5); | 1768 |
1090 png_ptr->background.green = (png_uint_16)(pow( | 1769 png_ptr->background_1.blue = png_gamma_correct(png_ptr, |
1091 (double)png_ptr->background.green / m, gs) * m + .5); | 1770 png_ptr->background.blue, g); |
1092 png_ptr->background.blue = (png_uint_16)(pow( | 1771 } |
1093 (double)png_ptr->background.blue / m, gs) * m + .5); | 1772 |
| 1773 if (gs_sig != 0) |
| 1774 { |
| 1775 png_ptr->background.red = png_gamma_correct(png_ptr, |
| 1776 png_ptr->background.red, gs); |
| 1777 |
| 1778 png_ptr->background.green = png_gamma_correct(png_ptr, |
| 1779 png_ptr->background.green, gs); |
| 1780 |
| 1781 png_ptr->background.blue = png_gamma_correct(png_ptr, |
| 1782 png_ptr->background.blue, gs); |
| 1783 } |
1094 } | 1784 } |
| 1785 |
1095 else | 1786 else |
1096 { | 1787 { |
1097 /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ | 1788 /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ |
1098 png_ptr->background_1.red = png_ptr->background_1.green | 1789 png_ptr->background_1.red = png_ptr->background_1.green |
1099 = png_ptr->background_1.blue = png_ptr->background_1.gray; | 1790 = png_ptr->background_1.blue = png_ptr->background_1.gray; |
| 1791 |
1100 png_ptr->background.red = png_ptr->background.green | 1792 png_ptr->background.red = png_ptr->background.green |
1101 = png_ptr->background.blue = png_ptr->background.gray; | 1793 = png_ptr->background.blue = png_ptr->background.gray; |
1102 } | 1794 } |
1103 } | 1795 |
1104 } | 1796 /* The background is now in screen gamma: */ |
| 1797 png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; |
| 1798 } /* color_type != PNG_COLOR_TYPE_PALETTE */ |
| 1799 }/* png_ptr->transformations & PNG_BACKGROUND */ |
| 1800 |
1105 else | 1801 else |
1106 /* Transformation does not include PNG_BACKGROUND */ | 1802 /* Transformation does not include PNG_BACKGROUND */ |
1107 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ | 1803 #endif /* READ_BACKGROUND */ |
1108 if (color_type == PNG_COLOR_TYPE_PALETTE) | 1804 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE |
| 1805 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
| 1806 /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ |
| 1807 && ((png_ptr->transformations & PNG_EXPAND) == 0 || |
| 1808 (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) |
| 1809 #endif |
| 1810 ) |
1109 { | 1811 { |
1110 png_colorp palette = png_ptr->palette; | 1812 png_colorp palette = png_ptr->palette; |
1111 int num_palette = png_ptr->num_palette; | 1813 int num_palette = png_ptr->num_palette; |
1112 int i; | 1814 int i; |
1113 | 1815 |
| 1816 /* NOTE: there are other transformations that should probably be in |
| 1817 * here too. |
| 1818 */ |
1114 for (i = 0; i < num_palette; i++) | 1819 for (i = 0; i < num_palette; i++) |
1115 { | 1820 { |
1116 palette[i].red = png_ptr->gamma_table[palette[i].red]; | 1821 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
1117 palette[i].green = png_ptr->gamma_table[palette[i].green]; | 1822 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
1118 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; | 1823 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
1119 } | 1824 } |
1120 | 1825 |
1121 /* Done the gamma correction. */ | 1826 /* Done the gamma correction. */ |
1122 png_ptr->transformations &= ~PNG_GAMMA; | 1827 png_ptr->transformations &= ~PNG_GAMMA; |
1123 } | 1828 } /* color_type == PALETTE && !PNG_BACKGROUND transformation */ |
1124 } | 1829 } |
1125 #ifdef PNG_READ_BACKGROUND_SUPPORTED | 1830 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
1126 else | 1831 else |
1127 #endif | 1832 #endif |
1128 #endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */ | 1833 #endif /* READ_GAMMA */ |
| 1834 |
1129 #ifdef PNG_READ_BACKGROUND_SUPPORTED | 1835 #ifdef PNG_READ_BACKGROUND_SUPPORTED |
1130 /* No GAMMA transformation */ | 1836 /* No GAMMA transformation (see the hanging else 4 lines above) */ |
1131 if ((png_ptr->transformations & PNG_BACKGROUND) && | 1837 if ((png_ptr->transformations & PNG_COMPOSE) != 0 && |
1132 (color_type == PNG_COLOR_TYPE_PALETTE)) | 1838 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) |
1133 { | 1839 { |
1134 int i; | 1840 int i; |
1135 int istop = (int)png_ptr->num_trans; | 1841 int istop = (int)png_ptr->num_trans; |
1136 png_color back; | 1842 png_color back; |
1137 png_colorp palette = png_ptr->palette; | 1843 png_colorp palette = png_ptr->palette; |
1138 | 1844 |
1139 back.red = (png_byte)png_ptr->background.red; | 1845 back.red = (png_byte)png_ptr->background.red; |
1140 back.green = (png_byte)png_ptr->background.green; | 1846 back.green = (png_byte)png_ptr->background.green; |
1141 back.blue = (png_byte)png_ptr->background.blue; | 1847 back.blue = (png_byte)png_ptr->background.blue; |
1142 | 1848 |
1143 for (i = 0; i < istop; i++) | 1849 for (i = 0; i < istop; i++) |
1144 { | 1850 { |
1145 if (png_ptr->trans[i] == 0) | 1851 if (png_ptr->trans_alpha[i] == 0) |
1146 { | 1852 { |
1147 palette[i] = back; | 1853 palette[i] = back; |
1148 } | 1854 } |
1149 else if (png_ptr->trans[i] != 0xff) | 1855 |
| 1856 else if (png_ptr->trans_alpha[i] != 0xff) |
1150 { | 1857 { |
1151 /* The png_composite() macro is defined in png.h */ | 1858 /* The png_composite() macro is defined in png.h */ |
1152 png_composite(palette[i].red, palette[i].red, | 1859 png_composite(palette[i].red, palette[i].red, |
1153 png_ptr->trans[i], back.red); | 1860 png_ptr->trans_alpha[i], back.red); |
| 1861 |
1154 png_composite(palette[i].green, palette[i].green, | 1862 png_composite(palette[i].green, palette[i].green, |
1155 png_ptr->trans[i], back.green); | 1863 png_ptr->trans_alpha[i], back.green); |
| 1864 |
1156 png_composite(palette[i].blue, palette[i].blue, | 1865 png_composite(palette[i].blue, palette[i].blue, |
1157 png_ptr->trans[i], back.blue); | 1866 png_ptr->trans_alpha[i], back.blue); |
1158 } | 1867 } |
1159 } | 1868 } |
1160 | 1869 |
1161 /* Handled alpha, still need to strip the channel. */ | 1870 png_ptr->transformations &= ~PNG_COMPOSE; |
1162 png_ptr->transformations &= ~PNG_BACKGROUND; | 1871 } |
1163 png_ptr->transformations |= PNG_STRIP_ALPHA; | 1872 #endif /* READ_BACKGROUND */ |
1164 } | |
1165 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ | |
1166 | 1873 |
1167 #ifdef PNG_READ_SHIFT_SUPPORTED | 1874 #ifdef PNG_READ_SHIFT_SUPPORTED |
1168 if ((png_ptr->transformations & PNG_SHIFT) && | 1875 if ((png_ptr->transformations & PNG_SHIFT) != 0 && |
1169 !(png_ptr->transformations & PNG_EXPAND) && | 1876 (png_ptr->transformations & PNG_EXPAND) == 0 && |
1170 (color_type == PNG_COLOR_TYPE_PALETTE)) | 1877 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) |
1171 { | 1878 { |
1172 png_uint_16 i; | 1879 int i; |
1173 png_uint_16 istop = png_ptr->num_palette; | 1880 int istop = png_ptr->num_palette; |
1174 int sr = 8 - png_ptr->sig_bit.red; | 1881 int shift = 8 - png_ptr->sig_bit.red; |
1175 int sg = 8 - png_ptr->sig_bit.green; | |
1176 int sb = 8 - png_ptr->sig_bit.blue; | |
1177 | |
1178 if (sr < 0 || sr > 8) | |
1179 sr = 0; | |
1180 if (sg < 0 || sg > 8) | |
1181 sg = 0; | |
1182 if (sb < 0 || sb > 8) | |
1183 sb = 0; | |
1184 for (i = 0; i < istop; i++) | |
1185 { | |
1186 png_ptr->palette[i].red >>= sr; | |
1187 png_ptr->palette[i].green >>= sg; | |
1188 png_ptr->palette[i].blue >>= sb; | |
1189 } | |
1190 | 1882 |
1191 png_ptr->transformations &= ~PNG_SHIFT; | 1883 png_ptr->transformations &= ~PNG_SHIFT; |
1192 } | 1884 |
1193 #endif /* PNG_READ_SHIFT_SUPPORTED */ | 1885 /* significant bits can be in the range 1 to 7 for a meaninful result, if |
1194 } | 1886 * the number of significant bits is 0 then no shift is done (this is an |
1195 #if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \ | 1887 * error condition which is silently ignored.) |
1196 && !defined(PNG_READ_BACKGROUND_SUPPORTED) | 1888 */ |
1197 if (png_ptr) | 1889 if (shift > 0 && shift < 8) |
1198 return; | 1890 for (i=0; i<istop; ++i) |
1199 #endif | 1891 { |
| 1892 int component = png_ptr->palette[i].red; |
| 1893 |
| 1894 component >>= shift; |
| 1895 png_ptr->palette[i].red = (png_byte)component; |
| 1896 } |
| 1897 |
| 1898 shift = 8 - png_ptr->sig_bit.green; |
| 1899 if (shift > 0 && shift < 8) |
| 1900 for (i=0; i<istop; ++i) |
| 1901 { |
| 1902 int component = png_ptr->palette[i].green; |
| 1903 |
| 1904 component >>= shift; |
| 1905 png_ptr->palette[i].green = (png_byte)component; |
| 1906 } |
| 1907 |
| 1908 shift = 8 - png_ptr->sig_bit.blue; |
| 1909 if (shift > 0 && shift < 8) |
| 1910 for (i=0; i<istop; ++i) |
| 1911 { |
| 1912 int component = png_ptr->palette[i].blue; |
| 1913 |
| 1914 component >>= shift; |
| 1915 png_ptr->palette[i].blue = (png_byte)component; |
| 1916 } |
| 1917 } |
| 1918 #endif /* READ_SHIFT */ |
1200 } | 1919 } |
1201 | 1920 |
1202 /* Modify the info structure to reflect the transformations. The | 1921 /* Modify the info structure to reflect the transformations. The |
1203 * info should be updated so a PNG file could be written with it, | 1922 * info should be updated so a PNG file could be written with it, |
1204 * assuming the transformations result in valid PNG data. | 1923 * assuming the transformations result in valid PNG data. |
1205 */ | 1924 */ |
1206 void /* PRIVATE */ | 1925 void /* PRIVATE */ |
1207 png_read_transform_info(png_structp png_ptr, png_infop info_ptr) | 1926 png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr) |
1208 { | 1927 { |
1209 png_debug(1, "in png_read_transform_info"); | 1928 png_debug(1, "in png_read_transform_info"); |
1210 | 1929 |
1211 #ifdef PNG_READ_EXPAND_SUPPORTED | 1930 #ifdef PNG_READ_EXPAND_SUPPORTED |
1212 if (png_ptr->transformations & PNG_EXPAND) | 1931 if ((png_ptr->transformations & PNG_EXPAND) != 0) |
1213 { | 1932 { |
1214 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | 1933 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
1215 { | 1934 { |
1216 if (png_ptr->num_trans) | 1935 /* This check must match what actually happens in |
| 1936 * png_do_expand_palette; if it ever checks the tRNS chunk to see if |
| 1937 * it is all opaque we must do the same (at present it does not.) |
| 1938 */ |
| 1939 if (png_ptr->num_trans > 0) |
1217 info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; | 1940 info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
| 1941 |
1218 else | 1942 else |
1219 info_ptr->color_type = PNG_COLOR_TYPE_RGB; | 1943 info_ptr->color_type = PNG_COLOR_TYPE_RGB; |
| 1944 |
1220 info_ptr->bit_depth = 8; | 1945 info_ptr->bit_depth = 8; |
1221 info_ptr->num_trans = 0; | 1946 info_ptr->num_trans = 0; |
| 1947 |
| 1948 if (png_ptr->palette == NULL) |
| 1949 png_error (png_ptr, "Palette is NULL in indexed image"); |
1222 } | 1950 } |
1223 else | 1951 else |
1224 { | 1952 { |
1225 if (png_ptr->num_trans) | 1953 if (png_ptr->num_trans != 0) |
1226 { | 1954 { |
1227 if (png_ptr->transformations & PNG_EXPAND_tRNS) | 1955 if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0) |
1228 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; | 1956 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
1229 } | 1957 } |
1230 if (info_ptr->bit_depth < 8) | 1958 if (info_ptr->bit_depth < 8) |
1231 info_ptr->bit_depth = 8; | 1959 info_ptr->bit_depth = 8; |
| 1960 |
1232 info_ptr->num_trans = 0; | 1961 info_ptr->num_trans = 0; |
1233 } | 1962 } |
1234 } | 1963 } |
1235 #endif | 1964 #endif |
1236 | 1965 |
1237 #ifdef PNG_READ_BACKGROUND_SUPPORTED | 1966 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ |
1238 if (png_ptr->transformations & PNG_BACKGROUND) | 1967 defined(PNG_READ_ALPHA_MODE_SUPPORTED) |
1239 { | 1968 /* The following is almost certainly wrong unless the background value is in |
1240 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; | 1969 * the screen space! |
1241 info_ptr->num_trans = 0; | 1970 */ |
| 1971 if ((png_ptr->transformations & PNG_COMPOSE) != 0) |
1242 info_ptr->background = png_ptr->background; | 1972 info_ptr->background = png_ptr->background; |
1243 } | |
1244 #endif | 1973 #endif |
1245 | 1974 |
1246 #ifdef PNG_READ_GAMMA_SUPPORTED | 1975 #ifdef PNG_READ_GAMMA_SUPPORTED |
1247 if (png_ptr->transformations & PNG_GAMMA) | 1976 /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4), |
1248 { | 1977 * however it seems that the code in png_init_read_transformations, which has |
1249 #ifdef PNG_FLOATING_POINT_SUPPORTED | 1978 * been called before this from png_read_update_info->png_read_start_row |
1250 info_ptr->gamma = png_ptr->gamma; | 1979 * sometimes does the gamma transform and cancels the flag. |
1251 #endif | 1980 * |
1252 #ifdef PNG_FIXED_POINT_SUPPORTED | 1981 * TODO: this looks wrong; the info_ptr should end up with a gamma equal to |
1253 info_ptr->int_gamma = png_ptr->int_gamma; | 1982 * the screen_gamma value. The following probably results in weirdness if |
1254 #endif | 1983 * the info_ptr is used by the app after the rows have been read. |
1255 } | 1984 */ |
1256 #endif | 1985 info_ptr->colorspace.gamma = png_ptr->colorspace.gamma; |
1257 | 1986 #endif |
1258 #ifdef PNG_READ_16_TO_8_SUPPORTED | 1987 |
1259 if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16)) | 1988 if (info_ptr->bit_depth == 16) |
1260 info_ptr->bit_depth = 8; | 1989 { |
1261 #endif | 1990 # ifdef PNG_READ_16BIT_SUPPORTED |
| 1991 # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
| 1992 if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) |
| 1993 info_ptr->bit_depth = 8; |
| 1994 # endif |
| 1995 |
| 1996 # ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
| 1997 if ((png_ptr->transformations & PNG_16_TO_8) != 0) |
| 1998 info_ptr->bit_depth = 8; |
| 1999 # endif |
| 2000 |
| 2001 # else |
| 2002 /* No 16-bit support: force chopping 16-bit input down to 8, in this case |
| 2003 * the app program can chose if both APIs are available by setting the |
| 2004 * correct scaling to use. |
| 2005 */ |
| 2006 # ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
| 2007 /* For compatibility with previous versions use the strip method by |
| 2008 * default. This code works because if PNG_SCALE_16_TO_8 is already |
| 2009 * set the code below will do that in preference to the chop. |
| 2010 */ |
| 2011 png_ptr->transformations |= PNG_16_TO_8; |
| 2012 info_ptr->bit_depth = 8; |
| 2013 # else |
| 2014 |
| 2015 # ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
| 2016 png_ptr->transformations |= PNG_SCALE_16_TO_8; |
| 2017 info_ptr->bit_depth = 8; |
| 2018 # else |
| 2019 |
| 2020 CONFIGURATION ERROR: you must enable at least one 16 to 8 method |
| 2021 # endif |
| 2022 # endif |
| 2023 #endif /* !READ_16BIT */ |
| 2024 } |
1262 | 2025 |
1263 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | 2026 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
1264 if (png_ptr->transformations & PNG_GRAY_TO_RGB) | 2027 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0) |
1265 info_ptr->color_type |= PNG_COLOR_MASK_COLOR; | 2028 info_ptr->color_type = (png_byte)(info_ptr->color_type | |
| 2029 PNG_COLOR_MASK_COLOR); |
1266 #endif | 2030 #endif |
1267 | 2031 |
1268 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | 2032 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
1269 if (png_ptr->transformations & PNG_RGB_TO_GRAY) | 2033 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) |
1270 info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; | 2034 info_ptr->color_type = (png_byte)(info_ptr->color_type & |
1271 #endif | 2035 ~PNG_COLOR_MASK_COLOR); |
1272 | 2036 #endif |
1273 #ifdef PNG_READ_DITHER_SUPPORTED | 2037 |
1274 if (png_ptr->transformations & PNG_DITHER) | 2038 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
| 2039 if ((png_ptr->transformations & PNG_QUANTIZE) != 0) |
1275 { | 2040 { |
1276 if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || | 2041 if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
1277 (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && | 2042 (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && |
1278 png_ptr->palette_lookup && info_ptr->bit_depth == 8) | 2043 png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8) |
1279 { | 2044 { |
1280 info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; | 2045 info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; |
1281 } | 2046 } |
1282 } | 2047 } |
1283 #endif | 2048 #endif |
1284 | 2049 |
| 2050 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
| 2051 if ((png_ptr->transformations & PNG_EXPAND_16) != 0 && |
| 2052 info_ptr->bit_depth == 8 && |
| 2053 info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) |
| 2054 { |
| 2055 info_ptr->bit_depth = 16; |
| 2056 } |
| 2057 #endif |
| 2058 |
1285 #ifdef PNG_READ_PACK_SUPPORTED | 2059 #ifdef PNG_READ_PACK_SUPPORTED |
1286 if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) | 2060 if ((png_ptr->transformations & PNG_PACK) != 0 && |
| 2061 (info_ptr->bit_depth < 8)) |
1287 info_ptr->bit_depth = 8; | 2062 info_ptr->bit_depth = 8; |
1288 #endif | 2063 #endif |
1289 | 2064 |
1290 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | 2065 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
1291 info_ptr->channels = 1; | 2066 info_ptr->channels = 1; |
1292 else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) | 2067 |
| 2068 else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0) |
1293 info_ptr->channels = 3; | 2069 info_ptr->channels = 3; |
| 2070 |
1294 else | 2071 else |
1295 info_ptr->channels = 1; | 2072 info_ptr->channels = 1; |
1296 | 2073 |
1297 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | 2074 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
1298 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) | 2075 if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0) |
1299 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; | 2076 { |
1300 #endif | 2077 info_ptr->color_type = (png_byte)(info_ptr->color_type & |
1301 | 2078 ~PNG_COLOR_MASK_ALPHA); |
1302 if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) | 2079 info_ptr->num_trans = 0; |
| 2080 } |
| 2081 #endif |
| 2082 |
| 2083 if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0) |
1303 info_ptr->channels++; | 2084 info_ptr->channels++; |
1304 | 2085 |
1305 #ifdef PNG_READ_FILLER_SUPPORTED | 2086 #ifdef PNG_READ_FILLER_SUPPORTED |
1306 /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ | 2087 /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ |
1307 if ((png_ptr->transformations & PNG_FILLER) && | 2088 if ((png_ptr->transformations & PNG_FILLER) != 0 && |
1308 ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || | 2089 (info_ptr->color_type == PNG_COLOR_TYPE_RGB || |
1309 (info_ptr->color_type == PNG_COLOR_TYPE_GRAY))) | 2090 info_ptr->color_type == PNG_COLOR_TYPE_GRAY)) |
1310 { | 2091 { |
1311 info_ptr->channels++; | 2092 info_ptr->channels++; |
1312 /* If adding a true alpha channel not just filler */ | 2093 /* If adding a true alpha channel not just filler */ |
1313 #ifndef PNG_1_0_X | 2094 if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0) |
1314 if (png_ptr->transformations & PNG_ADD_ALPHA) | 2095 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
1315 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; | |
1316 #endif | |
1317 } | 2096 } |
1318 #endif | 2097 #endif |
1319 | 2098 |
1320 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ | 2099 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ |
1321 defined(PNG_READ_USER_TRANSFORM_SUPPORTED) | 2100 defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
1322 if (png_ptr->transformations & PNG_USER_TRANSFORM) | 2101 if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) |
1323 { | 2102 { |
1324 if (info_ptr->bit_depth < png_ptr->user_transform_depth) | 2103 if (png_ptr->user_transform_depth != 0) |
1325 info_ptr->bit_depth = png_ptr->user_transform_depth; | 2104 info_ptr->bit_depth = png_ptr->user_transform_depth; |
1326 if (info_ptr->channels < png_ptr->user_transform_channels) | 2105 |
| 2106 if (png_ptr->user_transform_channels != 0) |
1327 info_ptr->channels = png_ptr->user_transform_channels; | 2107 info_ptr->channels = png_ptr->user_transform_channels; |
1328 } | 2108 } |
1329 #endif | 2109 #endif |
1330 | 2110 |
1331 info_ptr->pixel_depth = (png_byte)(info_ptr->channels * | 2111 info_ptr->pixel_depth = (png_byte)(info_ptr->channels * |
1332 info_ptr->bit_depth); | 2112 info_ptr->bit_depth); |
1333 | 2113 |
1334 info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); | 2114 info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); |
1335 | 2115 |
| 2116 /* Adding in 1.5.4: cache the above value in png_struct so that we can later |
| 2117 * check in png_rowbytes that the user buffer won't get overwritten. Note |
| 2118 * that the field is not always set - if png_read_update_info isn't called |
| 2119 * the application has to either not do any transforms or get the calculation |
| 2120 * right itself. |
| 2121 */ |
| 2122 png_ptr->info_rowbytes = info_ptr->rowbytes; |
| 2123 |
1336 #ifndef PNG_READ_EXPAND_SUPPORTED | 2124 #ifndef PNG_READ_EXPAND_SUPPORTED |
1337 if (png_ptr) | 2125 if (png_ptr != NULL) |
1338 return; | 2126 return; |
1339 #endif | 2127 #endif |
1340 } | 2128 } |
1341 | 2129 |
1342 /* Transform the row. The order of transformations is significant, | |
1343 * and is very touchy. If you add a transformation, take care to | |
1344 * decide how it fits in with the other transformations here. | |
1345 */ | |
1346 void /* PRIVATE */ | |
1347 png_do_read_transformations(png_structp png_ptr) | |
1348 { | |
1349 png_debug(1, "in png_do_read_transformations"); | |
1350 | |
1351 if (png_ptr->row_buf == NULL) | |
1352 { | |
1353 #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE) | |
1354 char msg[50]; | |
1355 | |
1356 png_snprintf2(msg, 50, | |
1357 "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number, | |
1358 png_ptr->pass); | |
1359 png_error(png_ptr, msg); | |
1360 #else | |
1361 png_error(png_ptr, "NULL row buffer"); | |
1362 #endif | |
1363 } | |
1364 #ifdef PNG_WARN_UNINITIALIZED_ROW | |
1365 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) | |
1366 /* Application has failed to call either png_read_start_image() | |
1367 * or png_read_update_info() after setting transforms that expand | |
1368 * pixels. This check added to libpng-1.2.19 | |
1369 */ | |
1370 #if (PNG_WARN_UNINITIALIZED_ROW==1) | |
1371 png_error(png_ptr, "Uninitialized row"); | |
1372 #else | |
1373 png_warning(png_ptr, "Uninitialized row"); | |
1374 #endif | |
1375 #endif | |
1376 | |
1377 #ifdef PNG_READ_EXPAND_SUPPORTED | |
1378 if (png_ptr->transformations & PNG_EXPAND) | |
1379 { | |
1380 if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) | |
1381 { | |
1382 if (png_ptr->palette == NULL) | |
1383 png_error (png_ptr, "Palette is NULL in indexed image"); | |
1384 | |
1385 png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1386 png_ptr->palette, png_ptr->trans, png_ptr->num_trans); | |
1387 } | |
1388 else | |
1389 { | |
1390 if (png_ptr->num_trans && | |
1391 (png_ptr->transformations & PNG_EXPAND_tRNS)) | |
1392 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1393 &(png_ptr->trans_values)); | |
1394 else | |
1395 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1396 NULL); | |
1397 } | |
1398 } | |
1399 #endif | |
1400 | |
1401 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED | |
1402 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) | |
1403 png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1404 PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)); | |
1405 #endif | |
1406 | |
1407 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | |
1408 if (png_ptr->transformations & PNG_RGB_TO_GRAY) | |
1409 { | |
1410 int rgb_error = | |
1411 png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), | |
1412 png_ptr->row_buf + 1); | |
1413 if (rgb_error) | |
1414 { | |
1415 png_ptr->rgb_to_gray_status=1; | |
1416 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == | |
1417 PNG_RGB_TO_GRAY_WARN) | |
1418 png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); | |
1419 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == | |
1420 PNG_RGB_TO_GRAY_ERR) | |
1421 png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); | |
1422 } | |
1423 } | |
1424 #endif | |
1425 | |
1426 /* From Andreas Dilger e-mail to png-implement, 26 March 1998: | |
1427 * | |
1428 * In most cases, the "simple transparency" should be done prior to doing | |
1429 * gray-to-RGB, or you will have to test 3x as many bytes to check if a | |
1430 * pixel is transparent. You would also need to make sure that the | |
1431 * transparency information is upgraded to RGB. | |
1432 * | |
1433 * To summarize, the current flow is: | |
1434 * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite | |
1435 * with background "in place" if transparent, | |
1436 * convert to RGB if necessary | |
1437 * - Gray + alpha -> composite with gray background and remove alpha bytes, | |
1438 * convert to RGB if necessary | |
1439 * | |
1440 * To support RGB backgrounds for gray images we need: | |
1441 * - Gray + simple transparency -> convert to RGB + simple transparency, | |
1442 * compare 3 or 6 bytes and composite with | |
1443 * background "in place" if transparent | |
1444 * (3x compare/pixel compared to doing | |
1445 * composite with gray bkgrnd) | |
1446 * - Gray + alpha -> convert to RGB + alpha, composite with background and | |
1447 * remove alpha bytes (3x float | |
1448 * operations/pixel compared with composite | |
1449 * on gray background) | |
1450 * | |
1451 * Greg's change will do this. The reason it wasn't done before is for | |
1452 * performance, as this increases the per-pixel operations. If we would check | |
1453 * in advance if the background was gray or RGB, and position the gray-to-RGB | |
1454 * transform appropriately, then it would save a lot of work/time. | |
1455 */ | |
1456 | |
1457 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | |
1458 /* If gray -> RGB, do so now only if background is non-gray; else do later | |
1459 * for performance reasons | |
1460 */ | |
1461 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && | |
1462 !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) | |
1463 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1464 #endif | |
1465 | |
1466 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
1467 if ((png_ptr->transformations & PNG_BACKGROUND) && | |
1468 ((png_ptr->num_trans != 0 ) || | |
1469 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) | |
1470 png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1471 &(png_ptr->trans_values), &(png_ptr->background) | |
1472 #ifdef PNG_READ_GAMMA_SUPPORTED | |
1473 , &(png_ptr->background_1), | |
1474 png_ptr->gamma_table, png_ptr->gamma_from_1, | |
1475 png_ptr->gamma_to_1, png_ptr->gamma_16_table, | |
1476 png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, | |
1477 png_ptr->gamma_shift | |
1478 #endif | |
1479 ); | |
1480 #endif | |
1481 | |
1482 #ifdef PNG_READ_GAMMA_SUPPORTED | |
1483 if ((png_ptr->transformations & PNG_GAMMA) && | |
1484 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
1485 !((png_ptr->transformations & PNG_BACKGROUND) && | |
1486 ((png_ptr->num_trans != 0) || | |
1487 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && | |
1488 #endif | |
1489 (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) | |
1490 png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1491 png_ptr->gamma_table, png_ptr->gamma_16_table, | |
1492 png_ptr->gamma_shift); | |
1493 #endif | |
1494 | |
1495 #ifdef PNG_READ_16_TO_8_SUPPORTED | |
1496 if (png_ptr->transformations & PNG_16_TO_8) | |
1497 png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1498 #endif | |
1499 | |
1500 #ifdef PNG_READ_DITHER_SUPPORTED | |
1501 if (png_ptr->transformations & PNG_DITHER) | |
1502 { | |
1503 png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1504 png_ptr->palette_lookup, png_ptr->dither_index); | |
1505 if (png_ptr->row_info.rowbytes == (png_uint_32)0) | |
1506 png_error(png_ptr, "png_do_dither returned rowbytes=0"); | |
1507 } | |
1508 #endif | |
1509 | |
1510 #ifdef PNG_READ_INVERT_SUPPORTED | |
1511 if (png_ptr->transformations & PNG_INVERT_MONO) | |
1512 png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1513 #endif | |
1514 | |
1515 #ifdef PNG_READ_SHIFT_SUPPORTED | |
1516 if (png_ptr->transformations & PNG_SHIFT) | |
1517 png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1518 &(png_ptr->shift)); | |
1519 #endif | |
1520 | |
1521 #ifdef PNG_READ_PACK_SUPPORTED | 2130 #ifdef PNG_READ_PACK_SUPPORTED |
1522 if (png_ptr->transformations & PNG_PACK) | |
1523 png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1524 #endif | |
1525 | |
1526 #ifdef PNG_READ_BGR_SUPPORTED | |
1527 if (png_ptr->transformations & PNG_BGR) | |
1528 png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1529 #endif | |
1530 | |
1531 #ifdef PNG_READ_PACKSWAP_SUPPORTED | |
1532 if (png_ptr->transformations & PNG_PACKSWAP) | |
1533 png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1534 #endif | |
1535 | |
1536 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | |
1537 /* If gray -> RGB, do so now only if we did not do so above */ | |
1538 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && | |
1539 (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) | |
1540 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1541 #endif | |
1542 | |
1543 #ifdef PNG_READ_FILLER_SUPPORTED | |
1544 if (png_ptr->transformations & PNG_FILLER) | |
1545 png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, | |
1546 (png_uint_32)png_ptr->filler, png_ptr->flags); | |
1547 #endif | |
1548 | |
1549 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED | |
1550 if (png_ptr->transformations & PNG_INVERT_ALPHA) | |
1551 png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1552 #endif | |
1553 | |
1554 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED | |
1555 if (png_ptr->transformations & PNG_SWAP_ALPHA) | |
1556 png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1557 #endif | |
1558 | |
1559 #ifdef PNG_READ_SWAP_SUPPORTED | |
1560 if (png_ptr->transformations & PNG_SWAP_BYTES) | |
1561 png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); | |
1562 #endif | |
1563 | |
1564 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED | |
1565 if (png_ptr->transformations & PNG_USER_TRANSFORM) | |
1566 { | |
1567 if (png_ptr->read_user_transform_fn != NULL) | |
1568 (*(png_ptr->read_user_transform_fn)) /* User read transform function */ | |
1569 (png_ptr, /* png_ptr */ | |
1570 &(png_ptr->row_info), /* row_info: */ | |
1571 /* png_uint_32 width; width of row */ | |
1572 /* png_uint_32 rowbytes; number of bytes in row */ | |
1573 /* png_byte color_type; color type of pixels */ | |
1574 /* png_byte bit_depth; bit depth of samples */ | |
1575 /* png_byte channels; number of channels (1-4) */ | |
1576 /* png_byte pixel_depth; bits per pixel (depth*channels) */ | |
1577 png_ptr->row_buf + 1); /* start of pixel data for row */ | |
1578 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED | |
1579 if (png_ptr->user_transform_depth) | |
1580 png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; | |
1581 if (png_ptr->user_transform_channels) | |
1582 png_ptr->row_info.channels = png_ptr->user_transform_channels; | |
1583 #endif | |
1584 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * | |
1585 png_ptr->row_info.channels); | |
1586 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, | |
1587 png_ptr->row_info.width); | |
1588 } | |
1589 #endif | |
1590 | |
1591 } | |
1592 | |
1593 #ifdef PNG_READ_PACK_SUPPORTED | |
1594 /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, | 2131 /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
1595 * without changing the actual values. Thus, if you had a row with | 2132 * without changing the actual values. Thus, if you had a row with |
1596 * a bit depth of 1, you would end up with bytes that only contained | 2133 * a bit depth of 1, you would end up with bytes that only contained |
1597 * the numbers 0 or 1. If you would rather they contain 0 and 255, use | 2134 * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
1598 * png_do_shift() after this. | 2135 * png_do_shift() after this. |
1599 */ | 2136 */ |
1600 void /* PRIVATE */ | 2137 static void |
1601 png_do_unpack(png_row_infop row_info, png_bytep row) | 2138 png_do_unpack(png_row_infop row_info, png_bytep row) |
1602 { | 2139 { |
1603 png_debug(1, "in png_do_unpack"); | 2140 png_debug(1, "in png_do_unpack"); |
1604 | 2141 |
1605 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
1606 if (row != NULL && row_info != NULL && row_info->bit_depth < 8) | |
1607 #else | |
1608 if (row_info->bit_depth < 8) | 2142 if (row_info->bit_depth < 8) |
1609 #endif | |
1610 { | 2143 { |
1611 png_uint_32 i; | 2144 png_uint_32 i; |
1612 png_uint_32 row_width=row_info->width; | 2145 png_uint_32 row_width=row_info->width; |
1613 | 2146 |
1614 switch (row_info->bit_depth) | 2147 switch (row_info->bit_depth) |
1615 { | 2148 { |
1616 case 1: | 2149 case 1: |
1617 { | 2150 { |
1618 png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); | 2151 png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); |
1619 png_bytep dp = row + (png_size_t)row_width - 1; | 2152 png_bytep dp = row + (png_size_t)row_width - 1; |
1620 png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); | 2153 png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); |
1621 for (i = 0; i < row_width; i++) | 2154 for (i = 0; i < row_width; i++) |
1622 { | 2155 { |
1623 *dp = (png_byte)((*sp >> shift) & 0x01); | 2156 *dp = (png_byte)((*sp >> shift) & 0x01); |
| 2157 |
1624 if (shift == 7) | 2158 if (shift == 7) |
1625 { | 2159 { |
1626 shift = 0; | 2160 shift = 0; |
1627 sp--; | 2161 sp--; |
1628 } | 2162 } |
| 2163 |
1629 else | 2164 else |
1630 shift++; | 2165 shift++; |
1631 | 2166 |
1632 dp--; | 2167 dp--; |
1633 } | 2168 } |
1634 break; | 2169 break; |
1635 } | 2170 } |
1636 | 2171 |
1637 case 2: | 2172 case 2: |
1638 { | 2173 { |
1639 | 2174 |
1640 png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); | 2175 png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); |
1641 png_bytep dp = row + (png_size_t)row_width - 1; | 2176 png_bytep dp = row + (png_size_t)row_width - 1; |
1642 png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); | 2177 png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
1643 for (i = 0; i < row_width; i++) | 2178 for (i = 0; i < row_width; i++) |
1644 { | 2179 { |
1645 *dp = (png_byte)((*sp >> shift) & 0x03); | 2180 *dp = (png_byte)((*sp >> shift) & 0x03); |
| 2181 |
1646 if (shift == 6) | 2182 if (shift == 6) |
1647 { | 2183 { |
1648 shift = 0; | 2184 shift = 0; |
1649 sp--; | 2185 sp--; |
1650 } | 2186 } |
| 2187 |
1651 else | 2188 else |
1652 shift += 2; | 2189 shift += 2; |
1653 | 2190 |
1654 dp--; | 2191 dp--; |
1655 } | 2192 } |
1656 break; | 2193 break; |
1657 } | 2194 } |
1658 | 2195 |
1659 case 4: | 2196 case 4: |
1660 { | 2197 { |
1661 png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); | 2198 png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); |
1662 png_bytep dp = row + (png_size_t)row_width - 1; | 2199 png_bytep dp = row + (png_size_t)row_width - 1; |
1663 png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); | 2200 png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
1664 for (i = 0; i < row_width; i++) | 2201 for (i = 0; i < row_width; i++) |
1665 { | 2202 { |
1666 *dp = (png_byte)((*sp >> shift) & 0x0f); | 2203 *dp = (png_byte)((*sp >> shift) & 0x0f); |
| 2204 |
1667 if (shift == 4) | 2205 if (shift == 4) |
1668 { | 2206 { |
1669 shift = 0; | 2207 shift = 0; |
1670 sp--; | 2208 sp--; |
1671 } | 2209 } |
| 2210 |
1672 else | 2211 else |
1673 shift = 4; | 2212 shift = 4; |
1674 | 2213 |
1675 dp--; | 2214 dp--; |
1676 } | 2215 } |
1677 break; | 2216 break; |
1678 } | 2217 } |
| 2218 |
| 2219 default: |
| 2220 break; |
1679 } | 2221 } |
1680 row_info->bit_depth = 8; | 2222 row_info->bit_depth = 8; |
1681 row_info->pixel_depth = (png_byte)(8 * row_info->channels); | 2223 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
1682 row_info->rowbytes = row_width * row_info->channels; | 2224 row_info->rowbytes = row_width * row_info->channels; |
1683 } | 2225 } |
1684 } | 2226 } |
1685 #endif | 2227 #endif |
1686 | 2228 |
1687 #ifdef PNG_READ_SHIFT_SUPPORTED | 2229 #ifdef PNG_READ_SHIFT_SUPPORTED |
1688 /* Reverse the effects of png_do_shift. This routine merely shifts the | 2230 /* Reverse the effects of png_do_shift. This routine merely shifts the |
1689 * pixels back to their significant bits values. Thus, if you have | 2231 * pixels back to their significant bits values. Thus, if you have |
1690 * a row of bit depth 8, but only 5 are significant, this will shift | 2232 * a row of bit depth 8, but only 5 are significant, this will shift |
1691 * the values back to 0 through 31. | 2233 * the values back to 0 through 31. |
1692 */ | 2234 */ |
1693 void /* PRIVATE */ | 2235 static void |
1694 png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) | 2236 png_do_unshift(png_row_infop row_info, png_bytep row, |
| 2237 png_const_color_8p sig_bits) |
1695 { | 2238 { |
| 2239 int color_type; |
| 2240 |
1696 png_debug(1, "in png_do_unshift"); | 2241 png_debug(1, "in png_do_unshift"); |
1697 | 2242 |
1698 if ( | 2243 /* The palette case has already been handled in the _init routine. */ |
1699 #ifdef PNG_USELESS_TESTS_SUPPORTED | 2244 color_type = row_info->color_type; |
1700 row != NULL && row_info != NULL && sig_bits != NULL && | 2245 |
1701 #endif | 2246 if (color_type != PNG_COLOR_TYPE_PALETTE) |
1702 row_info->color_type != PNG_COLOR_TYPE_PALETTE) | |
1703 { | 2247 { |
1704 int shift[4]; | 2248 int shift[4]; |
1705 int channels = 0; | 2249 int channels = 0; |
1706 int c; | 2250 int bit_depth = row_info->bit_depth; |
1707 png_uint_16 value = 0; | 2251 |
1708 png_uint_32 row_width = row_info->width; | 2252 if ((color_type & PNG_COLOR_MASK_COLOR) != 0) |
1709 | 2253 { |
1710 if (row_info->color_type & PNG_COLOR_MASK_COLOR) | 2254 shift[channels++] = bit_depth - sig_bits->red; |
1711 { | 2255 shift[channels++] = bit_depth - sig_bits->green; |
1712 shift[channels++] = row_info->bit_depth - sig_bits->red; | 2256 shift[channels++] = bit_depth - sig_bits->blue; |
1713 shift[channels++] = row_info->bit_depth - sig_bits->green; | 2257 } |
1714 shift[channels++] = row_info->bit_depth - sig_bits->blue; | 2258 |
1715 } | |
1716 else | 2259 else |
1717 { | 2260 { |
1718 shift[channels++] = row_info->bit_depth - sig_bits->gray; | 2261 shift[channels++] = bit_depth - sig_bits->gray; |
1719 } | 2262 } |
1720 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) | 2263 |
1721 { | 2264 if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) |
1722 shift[channels++] = row_info->bit_depth - sig_bits->alpha; | 2265 { |
1723 } | 2266 shift[channels++] = bit_depth - sig_bits->alpha; |
1724 | 2267 } |
1725 for (c = 0; c < channels; c++) | 2268 |
1726 { | 2269 { |
1727 if (shift[c] <= 0) | 2270 int c, have_shift; |
1728 shift[c] = 0; | 2271 |
1729 else | 2272 for (c = have_shift = 0; c < channels; ++c) |
1730 value = 1; | 2273 { |
1731 } | 2274 /* A shift of more than the bit depth is an error condition but it |
1732 | 2275 * gets ignored here. |
1733 if (!value) | 2276 */ |
1734 return; | 2277 if (shift[c] <= 0 || shift[c] >= bit_depth) |
1735 | 2278 shift[c] = 0; |
1736 switch (row_info->bit_depth) | 2279 |
1737 { | 2280 else |
| 2281 have_shift = 1; |
| 2282 } |
| 2283 |
| 2284 if (have_shift == 0) |
| 2285 return; |
| 2286 } |
| 2287 |
| 2288 switch (bit_depth) |
| 2289 { |
| 2290 default: |
| 2291 /* Must be 1bpp gray: should not be here! */ |
| 2292 /* NOTREACHED */ |
| 2293 break; |
| 2294 |
1738 case 2: | 2295 case 2: |
1739 { | 2296 /* Must be 2bpp gray */ |
1740 png_bytep bp; | 2297 /* assert(channels == 1 && shift[0] == 1) */ |
1741 png_uint_32 i; | 2298 { |
1742 png_uint_32 istop = row_info->rowbytes; | 2299 png_bytep bp = row; |
1743 | 2300 png_bytep bp_end = bp + row_info->rowbytes; |
1744 for (bp = row, i = 0; i < istop; i++) | 2301 |
1745 { | 2302 while (bp < bp_end) |
1746 *bp >>= 1; | 2303 { |
1747 *bp++ &= 0x55; | 2304 int b = (*bp >> 1) & 0x55; |
| 2305 *bp++ = (png_byte)b; |
1748 } | 2306 } |
1749 break; | 2307 break; |
1750 } | 2308 } |
1751 | 2309 |
1752 case 4: | 2310 case 4: |
1753 { | 2311 /* Must be 4bpp gray */ |
1754 png_bytep bp = row; | 2312 /* assert(channels == 1) */ |
1755 png_uint_32 i; | 2313 { |
1756 png_uint_32 istop = row_info->rowbytes; | 2314 png_bytep bp = row; |
1757 png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | | 2315 png_bytep bp_end = bp + row_info->rowbytes; |
1758 (png_byte)((int)0xf >> shift[0])); | 2316 int gray_shift = shift[0]; |
1759 | 2317 int mask = 0xf >> gray_shift; |
1760 for (i = 0; i < istop; i++) | 2318 |
1761 { | 2319 mask |= mask << 4; |
1762 *bp >>= shift[0]; | 2320 |
1763 *bp++ &= mask; | 2321 while (bp < bp_end) |
| 2322 { |
| 2323 int b = (*bp >> gray_shift) & mask; |
| 2324 *bp++ = (png_byte)b; |
1764 } | 2325 } |
1765 break; | 2326 break; |
1766 } | 2327 } |
1767 | 2328 |
1768 case 8: | 2329 case 8: |
1769 { | 2330 /* Single byte components, G, GA, RGB, RGBA */ |
1770 png_bytep bp = row; | 2331 { |
1771 png_uint_32 i; | 2332 png_bytep bp = row; |
1772 png_uint_32 istop = row_width * channels; | 2333 png_bytep bp_end = bp + row_info->rowbytes; |
1773 | 2334 int channel = 0; |
1774 for (i = 0; i < istop; i++) | 2335 |
1775 { | 2336 while (bp < bp_end) |
1776 *bp++ >>= shift[i%channels]; | 2337 { |
1777 } | 2338 int b = *bp >> shift[channel]; |
1778 break; | 2339 if (++channel >= channels) |
1779 } | 2340 channel = 0; |
1780 | 2341 *bp++ = (png_byte)b; |
| 2342 } |
| 2343 break; |
| 2344 } |
| 2345 |
| 2346 #ifdef PNG_READ_16BIT_SUPPORTED |
1781 case 16: | 2347 case 16: |
1782 { | 2348 /* Double byte components, G, GA, RGB, RGBA */ |
1783 png_bytep bp = row; | 2349 { |
1784 png_uint_32 i; | 2350 png_bytep bp = row; |
1785 png_uint_32 istop = channels * row_width; | 2351 png_bytep bp_end = bp + row_info->rowbytes; |
1786 | 2352 int channel = 0; |
1787 for (i = 0; i < istop; i++) | 2353 |
1788 { | 2354 while (bp < bp_end) |
1789 value = (png_uint_16)((*bp << 8) + *(bp + 1)); | 2355 { |
1790 value >>= shift[i%channels]; | 2356 int value = (bp[0] << 8) + bp[1]; |
| 2357 |
| 2358 value >>= shift[channel]; |
| 2359 if (++channel >= channels) |
| 2360 channel = 0; |
1791 *bp++ = (png_byte)(value >> 8); | 2361 *bp++ = (png_byte)(value >> 8); |
1792 *bp++ = (png_byte)(value & 0xff); | 2362 *bp++ = (png_byte)value; |
1793 } | 2363 } |
1794 break; | 2364 break; |
1795 } | 2365 } |
| 2366 #endif |
1796 } | 2367 } |
1797 } | 2368 } |
1798 } | 2369 } |
1799 #endif | 2370 #endif |
1800 | 2371 |
1801 #ifdef PNG_READ_16_TO_8_SUPPORTED | 2372 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
1802 /* Chop rows of bit depth 16 down to 8 */ | 2373 /* Scale rows of bit depth 16 down to 8 accurately */ |
1803 void /* PRIVATE */ | 2374 static void |
| 2375 png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) |
| 2376 { |
| 2377 png_debug(1, "in png_do_scale_16_to_8"); |
| 2378 |
| 2379 if (row_info->bit_depth == 16) |
| 2380 { |
| 2381 png_bytep sp = row; /* source */ |
| 2382 png_bytep dp = row; /* destination */ |
| 2383 png_bytep ep = sp + row_info->rowbytes; /* end+1 */ |
| 2384 |
| 2385 while (sp < ep) |
| 2386 { |
| 2387 /* The input is an array of 16-bit components, these must be scaled to |
| 2388 * 8 bits each. For a 16-bit value V the required value (from the PNG |
| 2389 * specification) is: |
| 2390 * |
| 2391 * (V * 255) / 65535 |
| 2392 * |
| 2393 * This reduces to round(V / 257), or floor((V + 128.5)/257) |
| 2394 * |
| 2395 * Represent V as the two byte value vhi.vlo. Make a guess that the |
| 2396 * result is the top byte of V, vhi, then the correction to this value |
| 2397 * is: |
| 2398 * |
| 2399 * error = floor(((V-vhi.vhi) + 128.5) / 257) |
| 2400 * = floor(((vlo-vhi) + 128.5) / 257) |
| 2401 * |
| 2402 * This can be approximated using integer arithmetic (and a signed |
| 2403 * shift): |
| 2404 * |
| 2405 * error = (vlo-vhi+128) >> 8; |
| 2406 * |
| 2407 * The approximate differs from the exact answer only when (vlo-vhi) is |
| 2408 * 128; it then gives a correction of +1 when the exact correction is |
| 2409 * 0. This gives 128 errors. The exact answer (correct for all 16-bit |
| 2410 * input values) is: |
| 2411 * |
| 2412 * error = (vlo-vhi+128)*65535 >> 24; |
| 2413 * |
| 2414 * An alternative arithmetic calculation which also gives no errors is: |
| 2415 * |
| 2416 * (V * 255 + 32895) >> 16 |
| 2417 */ |
| 2418 |
| 2419 png_int_32 tmp = *sp++; /* must be signed! */ |
| 2420 tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24; |
| 2421 *dp++ = (png_byte)tmp; |
| 2422 } |
| 2423 |
| 2424 row_info->bit_depth = 8; |
| 2425 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
| 2426 row_info->rowbytes = row_info->width * row_info->channels; |
| 2427 } |
| 2428 } |
| 2429 #endif |
| 2430 |
| 2431 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
| 2432 static void |
| 2433 /* Simply discard the low byte. This was the default behavior prior |
| 2434 * to libpng-1.5.4. |
| 2435 */ |
1804 png_do_chop(png_row_infop row_info, png_bytep row) | 2436 png_do_chop(png_row_infop row_info, png_bytep row) |
1805 { | 2437 { |
1806 png_debug(1, "in png_do_chop"); | 2438 png_debug(1, "in png_do_chop"); |
1807 | 2439 |
1808 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
1809 if (row != NULL && row_info != NULL && row_info->bit_depth == 16) | |
1810 #else | |
1811 if (row_info->bit_depth == 16) | 2440 if (row_info->bit_depth == 16) |
1812 #endif | |
1813 { | 2441 { |
1814 png_bytep sp = row; | 2442 png_bytep sp = row; /* source */ |
1815 png_bytep dp = row; | 2443 png_bytep dp = row; /* destination */ |
1816 png_uint_32 i; | 2444 png_bytep ep = sp + row_info->rowbytes; /* end+1 */ |
1817 png_uint_32 istop = row_info->width * row_info->channels; | 2445 |
1818 | 2446 while (sp < ep) |
1819 for (i = 0; i<istop; i++, sp += 2, dp++) | 2447 { |
1820 { | 2448 *dp++ = *sp; |
1821 #ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED | 2449 sp += 2; /* skip low byte */ |
1822 /* This does a more accurate scaling of the 16-bit color | 2450 } |
1823 * value, rather than a simple low-byte truncation. | 2451 |
1824 * | |
1825 * What the ideal calculation should be: | |
1826 * *dp = (((((png_uint_32)(*sp) << 8) | | |
1827 * (png_uint_32)(*(sp + 1))) * 255 + 127) | |
1828 * / (png_uint_32)65535L; | |
1829 * | |
1830 * GRR: no, I think this is what it really should be: | |
1831 * *dp = (((((png_uint_32)(*sp) << 8) | | |
1832 * (png_uint_32)(*(sp + 1))) + 128L) | |
1833 * / (png_uint_32)257L; | |
1834 * | |
1835 * GRR: here's the exact calculation with shifts: | |
1836 * temp = (((png_uint_32)(*sp) << 8) | | |
1837 * (png_uint_32)(*(sp + 1))) + 128L; | |
1838 * *dp = (temp - (temp >> 8)) >> 8; | |
1839 * | |
1840 * Approximate calculation with shift/add instead of multiply/divide: | |
1841 * *dp = ((((png_uint_32)(*sp) << 8) | | |
1842 * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; | |
1843 * | |
1844 * What we actually do to avoid extra shifting and conversion: | |
1845 */ | |
1846 | |
1847 *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); | |
1848 #else | |
1849 /* Simply discard the low order byte */ | |
1850 *dp = *sp; | |
1851 #endif | |
1852 } | |
1853 row_info->bit_depth = 8; | 2452 row_info->bit_depth = 8; |
1854 row_info->pixel_depth = (png_byte)(8 * row_info->channels); | 2453 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
1855 row_info->rowbytes = row_info->width * row_info->channels; | 2454 row_info->rowbytes = row_info->width * row_info->channels; |
1856 } | 2455 } |
1857 } | 2456 } |
1858 #endif | 2457 #endif |
1859 | 2458 |
1860 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED | 2459 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED |
1861 void /* PRIVATE */ | 2460 static void |
1862 png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) | 2461 png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) |
1863 { | 2462 { |
1864 png_debug(1, "in png_do_read_swap_alpha"); | 2463 png_debug(1, "in png_do_read_swap_alpha"); |
1865 | 2464 |
1866 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
1867 if (row != NULL && row_info != NULL) | |
1868 #endif | |
1869 { | 2465 { |
1870 png_uint_32 row_width = row_info->width; | 2466 png_uint_32 row_width = row_info->width; |
1871 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | 2467 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
1872 { | 2468 { |
1873 /* This converts from RGBA to ARGB */ | 2469 /* This converts from RGBA to ARGB */ |
1874 if (row_info->bit_depth == 8) | 2470 if (row_info->bit_depth == 8) |
1875 { | 2471 { |
1876 png_bytep sp = row + row_info->rowbytes; | 2472 png_bytep sp = row + row_info->rowbytes; |
1877 png_bytep dp = sp; | 2473 png_bytep dp = sp; |
1878 png_byte save; | 2474 png_byte save; |
1879 png_uint_32 i; | 2475 png_uint_32 i; |
1880 | 2476 |
1881 for (i = 0; i < row_width; i++) | 2477 for (i = 0; i < row_width; i++) |
1882 { | 2478 { |
1883 save = *(--sp); | 2479 save = *(--sp); |
1884 *(--dp) = *(--sp); | 2480 *(--dp) = *(--sp); |
1885 *(--dp) = *(--sp); | 2481 *(--dp) = *(--sp); |
1886 *(--dp) = *(--sp); | 2482 *(--dp) = *(--sp); |
1887 *(--dp) = save; | 2483 *(--dp) = save; |
1888 } | 2484 } |
1889 } | 2485 } |
| 2486 |
| 2487 #ifdef PNG_READ_16BIT_SUPPORTED |
1890 /* This converts from RRGGBBAA to AARRGGBB */ | 2488 /* This converts from RRGGBBAA to AARRGGBB */ |
1891 else | 2489 else |
1892 { | 2490 { |
1893 png_bytep sp = row + row_info->rowbytes; | 2491 png_bytep sp = row + row_info->rowbytes; |
1894 png_bytep dp = sp; | 2492 png_bytep dp = sp; |
1895 png_byte save[2]; | 2493 png_byte save[2]; |
1896 png_uint_32 i; | 2494 png_uint_32 i; |
1897 | 2495 |
1898 for (i = 0; i < row_width; i++) | 2496 for (i = 0; i < row_width; i++) |
1899 { | 2497 { |
1900 save[0] = *(--sp); | 2498 save[0] = *(--sp); |
1901 save[1] = *(--sp); | 2499 save[1] = *(--sp); |
1902 *(--dp) = *(--sp); | 2500 *(--dp) = *(--sp); |
1903 *(--dp) = *(--sp); | 2501 *(--dp) = *(--sp); |
1904 *(--dp) = *(--sp); | 2502 *(--dp) = *(--sp); |
1905 *(--dp) = *(--sp); | 2503 *(--dp) = *(--sp); |
1906 *(--dp) = *(--sp); | 2504 *(--dp) = *(--sp); |
1907 *(--dp) = *(--sp); | 2505 *(--dp) = *(--sp); |
1908 *(--dp) = save[0]; | 2506 *(--dp) = save[0]; |
1909 *(--dp) = save[1]; | 2507 *(--dp) = save[1]; |
1910 } | 2508 } |
1911 } | 2509 } |
| 2510 #endif |
1912 } | 2511 } |
| 2512 |
1913 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) | 2513 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
1914 { | 2514 { |
1915 /* This converts from GA to AG */ | 2515 /* This converts from GA to AG */ |
1916 if (row_info->bit_depth == 8) | 2516 if (row_info->bit_depth == 8) |
1917 { | 2517 { |
1918 png_bytep sp = row + row_info->rowbytes; | 2518 png_bytep sp = row + row_info->rowbytes; |
1919 png_bytep dp = sp; | 2519 png_bytep dp = sp; |
1920 png_byte save; | 2520 png_byte save; |
1921 png_uint_32 i; | 2521 png_uint_32 i; |
1922 | 2522 |
1923 for (i = 0; i < row_width; i++) | 2523 for (i = 0; i < row_width; i++) |
1924 { | 2524 { |
1925 save = *(--sp); | 2525 save = *(--sp); |
1926 *(--dp) = *(--sp); | 2526 *(--dp) = *(--sp); |
1927 *(--dp) = save; | 2527 *(--dp) = save; |
1928 } | 2528 } |
1929 } | 2529 } |
| 2530 |
| 2531 #ifdef PNG_READ_16BIT_SUPPORTED |
1930 /* This converts from GGAA to AAGG */ | 2532 /* This converts from GGAA to AAGG */ |
1931 else | 2533 else |
1932 { | 2534 { |
1933 png_bytep sp = row + row_info->rowbytes; | 2535 png_bytep sp = row + row_info->rowbytes; |
1934 png_bytep dp = sp; | 2536 png_bytep dp = sp; |
1935 png_byte save[2]; | 2537 png_byte save[2]; |
1936 png_uint_32 i; | 2538 png_uint_32 i; |
1937 | 2539 |
1938 for (i = 0; i < row_width; i++) | 2540 for (i = 0; i < row_width; i++) |
1939 { | 2541 { |
1940 save[0] = *(--sp); | 2542 save[0] = *(--sp); |
1941 save[1] = *(--sp); | 2543 save[1] = *(--sp); |
1942 *(--dp) = *(--sp); | 2544 *(--dp) = *(--sp); |
1943 *(--dp) = *(--sp); | 2545 *(--dp) = *(--sp); |
1944 *(--dp) = save[0]; | 2546 *(--dp) = save[0]; |
1945 *(--dp) = save[1]; | 2547 *(--dp) = save[1]; |
1946 } | 2548 } |
1947 } | 2549 } |
| 2550 #endif |
1948 } | 2551 } |
1949 } | 2552 } |
1950 } | 2553 } |
1951 #endif | 2554 #endif |
1952 | 2555 |
1953 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED | 2556 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
1954 void /* PRIVATE */ | 2557 static void |
1955 png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) | 2558 png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) |
1956 { | 2559 { |
| 2560 png_uint_32 row_width; |
1957 png_debug(1, "in png_do_read_invert_alpha"); | 2561 png_debug(1, "in png_do_read_invert_alpha"); |
1958 | 2562 |
1959 #ifdef PNG_USELESS_TESTS_SUPPORTED | 2563 row_width = row_info->width; |
1960 if (row != NULL && row_info != NULL) | 2564 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
1961 #endif | |
1962 { | 2565 { |
1963 png_uint_32 row_width = row_info->width; | 2566 if (row_info->bit_depth == 8) |
1964 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | |
1965 { | 2567 { |
1966 /* This inverts the alpha channel in RGBA */ | 2568 /* This inverts the alpha channel in RGBA */ |
1967 if (row_info->bit_depth == 8) | 2569 png_bytep sp = row + row_info->rowbytes; |
| 2570 png_bytep dp = sp; |
| 2571 png_uint_32 i; |
| 2572 |
| 2573 for (i = 0; i < row_width; i++) |
1968 { | 2574 { |
1969 png_bytep sp = row + row_info->rowbytes; | 2575 *(--dp) = (png_byte)(255 - *(--sp)); |
1970 png_bytep dp = sp; | |
1971 png_uint_32 i; | |
1972 | 2576 |
1973 for (i = 0; i < row_width; i++) | 2577 /* This does nothing: |
1974 { | 2578 *(--dp) = *(--sp); |
1975 *(--dp) = (png_byte)(255 - *(--sp)); | 2579 *(--dp) = *(--sp); |
1976 | 2580 *(--dp) = *(--sp); |
1977 /* This does nothing: | 2581 We can replace it with: |
1978 *(--dp) = *(--sp); | |
1979 *(--dp) = *(--sp); | |
1980 *(--dp) = *(--sp); | |
1981 We can replace it with: | |
1982 */ | 2582 */ |
1983 sp-=3; | 2583 sp-=3; |
1984 dp=sp; | 2584 dp=sp; |
1985 } | |
1986 } | |
1987 /* This inverts the alpha channel in RRGGBBAA */ | |
1988 else | |
1989 { | |
1990 png_bytep sp = row + row_info->rowbytes; | |
1991 png_bytep dp = sp; | |
1992 png_uint_32 i; | |
1993 | |
1994 for (i = 0; i < row_width; i++) | |
1995 { | |
1996 *(--dp) = (png_byte)(255 - *(--sp)); | |
1997 *(--dp) = (png_byte)(255 - *(--sp)); | |
1998 | |
1999 /* This does nothing: | |
2000 *(--dp) = *(--sp); | |
2001 *(--dp) = *(--sp); | |
2002 *(--dp) = *(--sp); | |
2003 *(--dp) = *(--sp); | |
2004 *(--dp) = *(--sp); | |
2005 *(--dp) = *(--sp); | |
2006 We can replace it with: | |
2007 */ | |
2008 sp-=6; | |
2009 dp=sp; | |
2010 } | |
2011 } | 2585 } |
2012 } | 2586 } |
2013 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) | 2587 |
| 2588 #ifdef PNG_READ_16BIT_SUPPORTED |
| 2589 /* This inverts the alpha channel in RRGGBBAA */ |
| 2590 else |
| 2591 { |
| 2592 png_bytep sp = row + row_info->rowbytes; |
| 2593 png_bytep dp = sp; |
| 2594 png_uint_32 i; |
| 2595 |
| 2596 for (i = 0; i < row_width; i++) |
| 2597 { |
| 2598 *(--dp) = (png_byte)(255 - *(--sp)); |
| 2599 *(--dp) = (png_byte)(255 - *(--sp)); |
| 2600 |
| 2601 /* This does nothing: |
| 2602 *(--dp) = *(--sp); |
| 2603 *(--dp) = *(--sp); |
| 2604 *(--dp) = *(--sp); |
| 2605 *(--dp) = *(--sp); |
| 2606 *(--dp) = *(--sp); |
| 2607 *(--dp) = *(--sp); |
| 2608 We can replace it with: |
| 2609 */ |
| 2610 sp-=6; |
| 2611 dp=sp; |
| 2612 } |
| 2613 } |
| 2614 #endif |
| 2615 } |
| 2616 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| 2617 { |
| 2618 if (row_info->bit_depth == 8) |
2014 { | 2619 { |
2015 /* This inverts the alpha channel in GA */ | 2620 /* This inverts the alpha channel in GA */ |
2016 if (row_info->bit_depth == 8) | 2621 png_bytep sp = row + row_info->rowbytes; |
| 2622 png_bytep dp = sp; |
| 2623 png_uint_32 i; |
| 2624 |
| 2625 for (i = 0; i < row_width; i++) |
2017 { | 2626 { |
2018 png_bytep sp = row + row_info->rowbytes; | 2627 *(--dp) = (png_byte)(255 - *(--sp)); |
2019 png_bytep dp = sp; | 2628 *(--dp) = *(--sp); |
2020 png_uint_32 i; | |
2021 | |
2022 for (i = 0; i < row_width; i++) | |
2023 { | |
2024 *(--dp) = (png_byte)(255 - *(--sp)); | |
2025 *(--dp) = *(--sp); | |
2026 } | |
2027 } | |
2028 /* This inverts the alpha channel in GGAA */ | |
2029 else | |
2030 { | |
2031 png_bytep sp = row + row_info->rowbytes; | |
2032 png_bytep dp = sp; | |
2033 png_uint_32 i; | |
2034 | |
2035 for (i = 0; i < row_width; i++) | |
2036 { | |
2037 *(--dp) = (png_byte)(255 - *(--sp)); | |
2038 *(--dp) = (png_byte)(255 - *(--sp)); | |
2039 /* | |
2040 *(--dp) = *(--sp); | |
2041 *(--dp) = *(--sp); | |
2042 */ | |
2043 sp-=2; | |
2044 dp=sp; | |
2045 } | |
2046 } | 2629 } |
2047 } | 2630 } |
| 2631 |
| 2632 #ifdef PNG_READ_16BIT_SUPPORTED |
| 2633 else |
| 2634 { |
| 2635 /* This inverts the alpha channel in GGAA */ |
| 2636 png_bytep sp = row + row_info->rowbytes; |
| 2637 png_bytep dp = sp; |
| 2638 png_uint_32 i; |
| 2639 |
| 2640 for (i = 0; i < row_width; i++) |
| 2641 { |
| 2642 *(--dp) = (png_byte)(255 - *(--sp)); |
| 2643 *(--dp) = (png_byte)(255 - *(--sp)); |
| 2644 /* |
| 2645 *(--dp) = *(--sp); |
| 2646 *(--dp) = *(--sp); |
| 2647 */ |
| 2648 sp-=2; |
| 2649 dp=sp; |
| 2650 } |
| 2651 } |
| 2652 #endif |
2048 } | 2653 } |
2049 } | 2654 } |
2050 #endif | 2655 #endif |
2051 | 2656 |
2052 #ifdef PNG_READ_FILLER_SUPPORTED | 2657 #ifdef PNG_READ_FILLER_SUPPORTED |
2053 /* Add filler channel if we have RGB color */ | 2658 /* Add filler channel if we have RGB color */ |
2054 void /* PRIVATE */ | 2659 static void |
2055 png_do_read_filler(png_row_infop row_info, png_bytep row, | 2660 png_do_read_filler(png_row_infop row_info, png_bytep row, |
2056 png_uint_32 filler, png_uint_32 flags) | 2661 png_uint_32 filler, png_uint_32 flags) |
2057 { | 2662 { |
2058 png_uint_32 i; | 2663 png_uint_32 i; |
2059 png_uint_32 row_width = row_info->width; | 2664 png_uint_32 row_width = row_info->width; |
2060 | 2665 |
2061 png_byte hi_filler = (png_byte)((filler>>8) & 0xff); | 2666 #ifdef PNG_READ_16BIT_SUPPORTED |
2062 png_byte lo_filler = (png_byte)(filler & 0xff); | 2667 png_byte hi_filler = (png_byte)(filler>>8); |
| 2668 #endif |
| 2669 png_byte lo_filler = (png_byte)filler; |
2063 | 2670 |
2064 png_debug(1, "in png_do_read_filler"); | 2671 png_debug(1, "in png_do_read_filler"); |
2065 | 2672 |
2066 if ( | 2673 if ( |
2067 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
2068 row != NULL && row_info != NULL && | |
2069 #endif | |
2070 row_info->color_type == PNG_COLOR_TYPE_GRAY) | 2674 row_info->color_type == PNG_COLOR_TYPE_GRAY) |
2071 { | 2675 { |
2072 if (row_info->bit_depth == 8) | 2676 if (row_info->bit_depth == 8) |
2073 { | 2677 { |
2074 /* This changes the data from G to GX */ | 2678 if ((flags & PNG_FLAG_FILLER_AFTER) != 0) |
2075 if (flags & PNG_FLAG_FILLER_AFTER) | |
2076 { | 2679 { |
| 2680 /* This changes the data from G to GX */ |
2077 png_bytep sp = row + (png_size_t)row_width; | 2681 png_bytep sp = row + (png_size_t)row_width; |
2078 png_bytep dp = sp + (png_size_t)row_width; | 2682 png_bytep dp = sp + (png_size_t)row_width; |
2079 for (i = 1; i < row_width; i++) | 2683 for (i = 1; i < row_width; i++) |
2080 { | 2684 { |
2081 *(--dp) = lo_filler; | 2685 *(--dp) = lo_filler; |
2082 *(--dp) = *(--sp); | 2686 *(--dp) = *(--sp); |
2083 } | 2687 } |
2084 *(--dp) = lo_filler; | 2688 *(--dp) = lo_filler; |
2085 row_info->channels = 2; | 2689 row_info->channels = 2; |
2086 row_info->pixel_depth = 16; | 2690 row_info->pixel_depth = 16; |
2087 row_info->rowbytes = row_width * 2; | 2691 row_info->rowbytes = row_width * 2; |
2088 } | 2692 } |
2089 /* This changes the data from G to XG */ | 2693 |
2090 else | 2694 else |
2091 { | 2695 { |
| 2696 /* This changes the data from G to XG */ |
2092 png_bytep sp = row + (png_size_t)row_width; | 2697 png_bytep sp = row + (png_size_t)row_width; |
2093 png_bytep dp = sp + (png_size_t)row_width; | 2698 png_bytep dp = sp + (png_size_t)row_width; |
2094 for (i = 0; i < row_width; i++) | 2699 for (i = 0; i < row_width; i++) |
2095 { | 2700 { |
2096 *(--dp) = *(--sp); | 2701 *(--dp) = *(--sp); |
2097 *(--dp) = lo_filler; | 2702 *(--dp) = lo_filler; |
2098 } | 2703 } |
2099 row_info->channels = 2; | 2704 row_info->channels = 2; |
2100 row_info->pixel_depth = 16; | 2705 row_info->pixel_depth = 16; |
2101 row_info->rowbytes = row_width * 2; | 2706 row_info->rowbytes = row_width * 2; |
2102 } | 2707 } |
2103 } | 2708 } |
| 2709 |
| 2710 #ifdef PNG_READ_16BIT_SUPPORTED |
2104 else if (row_info->bit_depth == 16) | 2711 else if (row_info->bit_depth == 16) |
2105 { | 2712 { |
2106 /* This changes the data from GG to GGXX */ | 2713 if ((flags & PNG_FLAG_FILLER_AFTER) != 0) |
2107 if (flags & PNG_FLAG_FILLER_AFTER) | |
2108 { | 2714 { |
| 2715 /* This changes the data from GG to GGXX */ |
2109 png_bytep sp = row + (png_size_t)row_width * 2; | 2716 png_bytep sp = row + (png_size_t)row_width * 2; |
2110 png_bytep dp = sp + (png_size_t)row_width * 2; | 2717 png_bytep dp = sp + (png_size_t)row_width * 2; |
2111 for (i = 1; i < row_width; i++) | 2718 for (i = 1; i < row_width; i++) |
2112 { | 2719 { |
| 2720 *(--dp) = lo_filler; |
2113 *(--dp) = hi_filler; | 2721 *(--dp) = hi_filler; |
2114 *(--dp) = lo_filler; | |
2115 *(--dp) = *(--sp); | 2722 *(--dp) = *(--sp); |
2116 *(--dp) = *(--sp); | 2723 *(--dp) = *(--sp); |
2117 } | 2724 } |
| 2725 *(--dp) = lo_filler; |
2118 *(--dp) = hi_filler; | 2726 *(--dp) = hi_filler; |
2119 *(--dp) = lo_filler; | |
2120 row_info->channels = 2; | 2727 row_info->channels = 2; |
2121 row_info->pixel_depth = 32; | 2728 row_info->pixel_depth = 32; |
2122 row_info->rowbytes = row_width * 4; | 2729 row_info->rowbytes = row_width * 4; |
2123 } | 2730 } |
2124 /* This changes the data from GG to XXGG */ | 2731 |
2125 else | 2732 else |
2126 { | 2733 { |
| 2734 /* This changes the data from GG to XXGG */ |
2127 png_bytep sp = row + (png_size_t)row_width * 2; | 2735 png_bytep sp = row + (png_size_t)row_width * 2; |
2128 png_bytep dp = sp + (png_size_t)row_width * 2; | 2736 png_bytep dp = sp + (png_size_t)row_width * 2; |
2129 for (i = 0; i < row_width; i++) | 2737 for (i = 0; i < row_width; i++) |
2130 { | 2738 { |
2131 *(--dp) = *(--sp); | 2739 *(--dp) = *(--sp); |
2132 *(--dp) = *(--sp); | 2740 *(--dp) = *(--sp); |
| 2741 *(--dp) = lo_filler; |
2133 *(--dp) = hi_filler; | 2742 *(--dp) = hi_filler; |
2134 *(--dp) = lo_filler; | |
2135 } | 2743 } |
2136 row_info->channels = 2; | 2744 row_info->channels = 2; |
2137 row_info->pixel_depth = 32; | 2745 row_info->pixel_depth = 32; |
2138 row_info->rowbytes = row_width * 4; | 2746 row_info->rowbytes = row_width * 4; |
2139 } | 2747 } |
2140 } | 2748 } |
| 2749 #endif |
2141 } /* COLOR_TYPE == GRAY */ | 2750 } /* COLOR_TYPE == GRAY */ |
2142 else if (row_info->color_type == PNG_COLOR_TYPE_RGB) | 2751 else if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
2143 { | 2752 { |
2144 if (row_info->bit_depth == 8) | 2753 if (row_info->bit_depth == 8) |
2145 { | 2754 { |
2146 /* This changes the data from RGB to RGBX */ | 2755 if ((flags & PNG_FLAG_FILLER_AFTER) != 0) |
2147 if (flags & PNG_FLAG_FILLER_AFTER) | |
2148 { | 2756 { |
| 2757 /* This changes the data from RGB to RGBX */ |
2149 png_bytep sp = row + (png_size_t)row_width * 3; | 2758 png_bytep sp = row + (png_size_t)row_width * 3; |
2150 png_bytep dp = sp + (png_size_t)row_width; | 2759 png_bytep dp = sp + (png_size_t)row_width; |
2151 for (i = 1; i < row_width; i++) | 2760 for (i = 1; i < row_width; i++) |
2152 { | 2761 { |
2153 *(--dp) = lo_filler; | 2762 *(--dp) = lo_filler; |
2154 *(--dp) = *(--sp); | 2763 *(--dp) = *(--sp); |
2155 *(--dp) = *(--sp); | 2764 *(--dp) = *(--sp); |
2156 *(--dp) = *(--sp); | 2765 *(--dp) = *(--sp); |
2157 } | 2766 } |
2158 *(--dp) = lo_filler; | 2767 *(--dp) = lo_filler; |
2159 row_info->channels = 4; | 2768 row_info->channels = 4; |
2160 row_info->pixel_depth = 32; | 2769 row_info->pixel_depth = 32; |
2161 row_info->rowbytes = row_width * 4; | 2770 row_info->rowbytes = row_width * 4; |
2162 } | 2771 } |
2163 /* This changes the data from RGB to XRGB */ | 2772 |
2164 else | 2773 else |
2165 { | 2774 { |
| 2775 /* This changes the data from RGB to XRGB */ |
2166 png_bytep sp = row + (png_size_t)row_width * 3; | 2776 png_bytep sp = row + (png_size_t)row_width * 3; |
2167 png_bytep dp = sp + (png_size_t)row_width; | 2777 png_bytep dp = sp + (png_size_t)row_width; |
2168 for (i = 0; i < row_width; i++) | 2778 for (i = 0; i < row_width; i++) |
2169 { | 2779 { |
2170 *(--dp) = *(--sp); | 2780 *(--dp) = *(--sp); |
2171 *(--dp) = *(--sp); | 2781 *(--dp) = *(--sp); |
2172 *(--dp) = *(--sp); | 2782 *(--dp) = *(--sp); |
2173 *(--dp) = lo_filler; | 2783 *(--dp) = lo_filler; |
2174 } | 2784 } |
2175 row_info->channels = 4; | 2785 row_info->channels = 4; |
2176 row_info->pixel_depth = 32; | 2786 row_info->pixel_depth = 32; |
2177 row_info->rowbytes = row_width * 4; | 2787 row_info->rowbytes = row_width * 4; |
2178 } | 2788 } |
2179 } | 2789 } |
| 2790 |
| 2791 #ifdef PNG_READ_16BIT_SUPPORTED |
2180 else if (row_info->bit_depth == 16) | 2792 else if (row_info->bit_depth == 16) |
2181 { | 2793 { |
2182 /* This changes the data from RRGGBB to RRGGBBXX */ | 2794 if ((flags & PNG_FLAG_FILLER_AFTER) != 0) |
2183 if (flags & PNG_FLAG_FILLER_AFTER) | |
2184 { | 2795 { |
| 2796 /* This changes the data from RRGGBB to RRGGBBXX */ |
2185 png_bytep sp = row + (png_size_t)row_width * 6; | 2797 png_bytep sp = row + (png_size_t)row_width * 6; |
2186 png_bytep dp = sp + (png_size_t)row_width * 2; | 2798 png_bytep dp = sp + (png_size_t)row_width * 2; |
2187 for (i = 1; i < row_width; i++) | 2799 for (i = 1; i < row_width; i++) |
2188 { | 2800 { |
| 2801 *(--dp) = lo_filler; |
2189 *(--dp) = hi_filler; | 2802 *(--dp) = hi_filler; |
2190 *(--dp) = lo_filler; | |
2191 *(--dp) = *(--sp); | 2803 *(--dp) = *(--sp); |
2192 *(--dp) = *(--sp); | 2804 *(--dp) = *(--sp); |
2193 *(--dp) = *(--sp); | 2805 *(--dp) = *(--sp); |
2194 *(--dp) = *(--sp); | 2806 *(--dp) = *(--sp); |
2195 *(--dp) = *(--sp); | 2807 *(--dp) = *(--sp); |
2196 *(--dp) = *(--sp); | 2808 *(--dp) = *(--sp); |
2197 } | 2809 } |
| 2810 *(--dp) = lo_filler; |
2198 *(--dp) = hi_filler; | 2811 *(--dp) = hi_filler; |
2199 *(--dp) = lo_filler; | |
2200 row_info->channels = 4; | 2812 row_info->channels = 4; |
2201 row_info->pixel_depth = 64; | 2813 row_info->pixel_depth = 64; |
2202 row_info->rowbytes = row_width * 8; | 2814 row_info->rowbytes = row_width * 8; |
2203 } | 2815 } |
2204 /* This changes the data from RRGGBB to XXRRGGBB */ | 2816 |
2205 else | 2817 else |
2206 { | 2818 { |
| 2819 /* This changes the data from RRGGBB to XXRRGGBB */ |
2207 png_bytep sp = row + (png_size_t)row_width * 6; | 2820 png_bytep sp = row + (png_size_t)row_width * 6; |
2208 png_bytep dp = sp + (png_size_t)row_width * 2; | 2821 png_bytep dp = sp + (png_size_t)row_width * 2; |
2209 for (i = 0; i < row_width; i++) | 2822 for (i = 0; i < row_width; i++) |
2210 { | 2823 { |
2211 *(--dp) = *(--sp); | 2824 *(--dp) = *(--sp); |
2212 *(--dp) = *(--sp); | 2825 *(--dp) = *(--sp); |
2213 *(--dp) = *(--sp); | 2826 *(--dp) = *(--sp); |
2214 *(--dp) = *(--sp); | 2827 *(--dp) = *(--sp); |
2215 *(--dp) = *(--sp); | 2828 *(--dp) = *(--sp); |
2216 *(--dp) = *(--sp); | 2829 *(--dp) = *(--sp); |
| 2830 *(--dp) = lo_filler; |
2217 *(--dp) = hi_filler; | 2831 *(--dp) = hi_filler; |
2218 *(--dp) = lo_filler; | |
2219 } | 2832 } |
| 2833 |
2220 row_info->channels = 4; | 2834 row_info->channels = 4; |
2221 row_info->pixel_depth = 64; | 2835 row_info->pixel_depth = 64; |
2222 row_info->rowbytes = row_width * 8; | 2836 row_info->rowbytes = row_width * 8; |
2223 } | 2837 } |
2224 } | 2838 } |
| 2839 #endif |
2225 } /* COLOR_TYPE == RGB */ | 2840 } /* COLOR_TYPE == RGB */ |
2226 } | 2841 } |
2227 #endif | 2842 #endif |
2228 | 2843 |
2229 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED | 2844 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
2230 /* Expand grayscale files to RGB, with or without alpha */ | 2845 /* Expand grayscale files to RGB, with or without alpha */ |
2231 void /* PRIVATE */ | 2846 static void |
2232 png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) | 2847 png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
2233 { | 2848 { |
2234 png_uint_32 i; | 2849 png_uint_32 i; |
2235 png_uint_32 row_width = row_info->width; | 2850 png_uint_32 row_width = row_info->width; |
2236 | 2851 |
2237 png_debug(1, "in png_do_gray_to_rgb"); | 2852 png_debug(1, "in png_do_gray_to_rgb"); |
2238 | 2853 |
2239 if (row_info->bit_depth >= 8 && | 2854 if (row_info->bit_depth >= 8 && |
2240 #ifdef PNG_USELESS_TESTS_SUPPORTED | 2855 (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0) |
2241 row != NULL && row_info != NULL && | |
2242 #endif | |
2243 !(row_info->color_type & PNG_COLOR_MASK_COLOR)) | |
2244 { | 2856 { |
2245 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) | 2857 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
2246 { | 2858 { |
2247 if (row_info->bit_depth == 8) | 2859 if (row_info->bit_depth == 8) |
2248 { | 2860 { |
| 2861 /* This changes G to RGB */ |
2249 png_bytep sp = row + (png_size_t)row_width - 1; | 2862 png_bytep sp = row + (png_size_t)row_width - 1; |
2250 png_bytep dp = sp + (png_size_t)row_width * 2; | 2863 png_bytep dp = sp + (png_size_t)row_width * 2; |
2251 for (i = 0; i < row_width; i++) | 2864 for (i = 0; i < row_width; i++) |
2252 { | 2865 { |
2253 *(dp--) = *sp; | 2866 *(dp--) = *sp; |
2254 *(dp--) = *sp; | 2867 *(dp--) = *sp; |
2255 *(dp--) = *(sp--); | 2868 *(dp--) = *(sp--); |
2256 } | 2869 } |
2257 } | 2870 } |
| 2871 |
2258 else | 2872 else |
2259 { | 2873 { |
| 2874 /* This changes GG to RRGGBB */ |
2260 png_bytep sp = row + (png_size_t)row_width * 2 - 1; | 2875 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
2261 png_bytep dp = sp + (png_size_t)row_width * 4; | 2876 png_bytep dp = sp + (png_size_t)row_width * 4; |
2262 for (i = 0; i < row_width; i++) | 2877 for (i = 0; i < row_width; i++) |
2263 { | 2878 { |
2264 *(dp--) = *sp; | 2879 *(dp--) = *sp; |
2265 *(dp--) = *(sp - 1); | 2880 *(dp--) = *(sp - 1); |
2266 *(dp--) = *sp; | 2881 *(dp--) = *sp; |
2267 *(dp--) = *(sp - 1); | 2882 *(dp--) = *(sp - 1); |
2268 *(dp--) = *(sp--); | 2883 *(dp--) = *(sp--); |
2269 *(dp--) = *(sp--); | 2884 *(dp--) = *(sp--); |
2270 } | 2885 } |
2271 } | 2886 } |
2272 } | 2887 } |
| 2888 |
2273 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) | 2889 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
2274 { | 2890 { |
2275 if (row_info->bit_depth == 8) | 2891 if (row_info->bit_depth == 8) |
2276 { | 2892 { |
| 2893 /* This changes GA to RGBA */ |
2277 png_bytep sp = row + (png_size_t)row_width * 2 - 1; | 2894 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
2278 png_bytep dp = sp + (png_size_t)row_width * 2; | 2895 png_bytep dp = sp + (png_size_t)row_width * 2; |
2279 for (i = 0; i < row_width; i++) | 2896 for (i = 0; i < row_width; i++) |
2280 { | 2897 { |
2281 *(dp--) = *(sp--); | 2898 *(dp--) = *(sp--); |
2282 *(dp--) = *sp; | 2899 *(dp--) = *sp; |
2283 *(dp--) = *sp; | 2900 *(dp--) = *sp; |
2284 *(dp--) = *(sp--); | 2901 *(dp--) = *(sp--); |
2285 } | 2902 } |
2286 } | 2903 } |
| 2904 |
2287 else | 2905 else |
2288 { | 2906 { |
| 2907 /* This changes GGAA to RRGGBBAA */ |
2289 png_bytep sp = row + (png_size_t)row_width * 4 - 1; | 2908 png_bytep sp = row + (png_size_t)row_width * 4 - 1; |
2290 png_bytep dp = sp + (png_size_t)row_width * 4; | 2909 png_bytep dp = sp + (png_size_t)row_width * 4; |
2291 for (i = 0; i < row_width; i++) | 2910 for (i = 0; i < row_width; i++) |
2292 { | 2911 { |
2293 *(dp--) = *(sp--); | 2912 *(dp--) = *(sp--); |
2294 *(dp--) = *(sp--); | 2913 *(dp--) = *(sp--); |
2295 *(dp--) = *sp; | 2914 *(dp--) = *sp; |
2296 *(dp--) = *(sp - 1); | 2915 *(dp--) = *(sp - 1); |
2297 *(dp--) = *sp; | 2916 *(dp--) = *sp; |
2298 *(dp--) = *(sp - 1); | 2917 *(dp--) = *(sp - 1); |
2299 *(dp--) = *(sp--); | 2918 *(dp--) = *(sp--); |
2300 *(dp--) = *(sp--); | 2919 *(dp--) = *(sp--); |
2301 } | 2920 } |
2302 } | 2921 } |
2303 } | 2922 } |
2304 row_info->channels += (png_byte)2; | 2923 row_info->channels = (png_byte)(row_info->channels + 2); |
2305 row_info->color_type |= PNG_COLOR_MASK_COLOR; | 2924 row_info->color_type |= PNG_COLOR_MASK_COLOR; |
2306 row_info->pixel_depth = (png_byte)(row_info->channels * | 2925 row_info->pixel_depth = (png_byte)(row_info->channels * |
2307 row_info->bit_depth); | 2926 row_info->bit_depth); |
2308 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | 2927 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
2309 } | 2928 } |
2310 } | 2929 } |
2311 #endif | 2930 #endif |
2312 | 2931 |
2313 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED | 2932 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
2314 /* Reduce RGB files to grayscale, with or without alpha | 2933 /* Reduce RGB files to grayscale, with or without alpha |
2315 * using the equation given in Poynton's ColorFAQ at | 2934 * using the equation given in Poynton's ColorFAQ of 1998-01-04 at |
2316 * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) | 2935 * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but |
2317 * New link: | 2936 * versions dated 1998 through November 2002 have been archived at |
| 2937 * http://web.archive.org/web/20000816232553/http://www.inforamp.net/ |
| 2938 * ~poynton/notes/colour_and_gamma/ColorFAQ.txt ) |
| 2939 * Charles Poynton poynton at poynton.com |
| 2940 * |
| 2941 * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B |
| 2942 * |
| 2943 * which can be expressed with integers as |
| 2944 * |
| 2945 * Y = (6969 * R + 23434 * G + 2365 * B)/32768 |
| 2946 * |
| 2947 * Poynton's current link (as of January 2003 through July 2011): |
2318 * <http://www.poynton.com/notes/colour_and_gamma/> | 2948 * <http://www.poynton.com/notes/colour_and_gamma/> |
2319 * Charles Poynton poynton at poynton.com | 2949 * has changed the numbers slightly: |
2320 * | 2950 * |
2321 * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B | 2951 * Y = 0.2126*R + 0.7152*G + 0.0722*B |
2322 * | |
2323 * We approximate this with | |
2324 * | |
2325 * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B | |
2326 * | 2952 * |
2327 * which can be expressed with integers as | 2953 * which can be expressed with integers as |
2328 * | 2954 * |
2329 * Y = (6969 * R + 23434 * G + 2365 * B)/32768 | 2955 * Y = (6966 * R + 23436 * G + 2366 * B)/32768 |
2330 * | 2956 * |
2331 * The calculation is to be done in a linear colorspace. | 2957 * Historically, however, libpng uses numbers derived from the ITU-R Rec 709 |
2332 * | 2958 * end point chromaticities and the D65 white point. Depending on the |
2333 * Other integer coefficents can be used via png_set_rgb_to_gray(). | 2959 * precision used for the D65 white point this produces a variety of different |
| 2960 * numbers, however if the four decimal place value used in ITU-R Rec 709 is |
| 2961 * used (0.3127,0.3290) the Y calculation would be: |
| 2962 * |
| 2963 * Y = (6968 * R + 23435 * G + 2366 * B)/32768 |
| 2964 * |
| 2965 * While this is correct the rounding results in an overflow for white, because |
| 2966 * the sum of the rounded coefficients is 32769, not 32768. Consequently |
| 2967 * libpng uses, instead, the closest non-overflowing approximation: |
| 2968 * |
| 2969 * Y = (6968 * R + 23434 * G + 2366 * B)/32768 |
| 2970 * |
| 2971 * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk |
| 2972 * (including an sRGB chunk) then the chromaticities are used to calculate the |
| 2973 * coefficients. See the chunk handling in pngrutil.c for more information. |
| 2974 * |
| 2975 * In all cases the calculation is to be done in a linear colorspace. If no |
| 2976 * gamma information is available to correct the encoding of the original RGB |
| 2977 * values this results in an implicit assumption that the original PNG RGB |
| 2978 * values were linear. |
| 2979 * |
| 2980 * Other integer coefficents can be used via png_set_rgb_to_gray(). Because |
| 2981 * the API takes just red and green coefficients the blue coefficient is |
| 2982 * calculated to make the sum 32768. This will result in different rounding |
| 2983 * to that used above. |
2334 */ | 2984 */ |
2335 int /* PRIVATE */ | 2985 static int |
2336 png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) | 2986 png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row) |
2337 | 2987 |
2338 { | 2988 { |
2339 png_uint_32 i; | |
2340 | |
2341 png_uint_32 row_width = row_info->width; | |
2342 int rgb_error = 0; | 2989 int rgb_error = 0; |
2343 | 2990 |
2344 png_debug(1, "in png_do_rgb_to_gray"); | 2991 png_debug(1, "in png_do_rgb_to_gray"); |
2345 | 2992 |
2346 if ( | 2993 if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 && |
2347 #ifdef PNG_USELESS_TESTS_SUPPORTED | 2994 (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0) |
2348 row != NULL && row_info != NULL && | |
2349 #endif | |
2350 (row_info->color_type & PNG_COLOR_MASK_COLOR)) | |
2351 { | 2995 { |
2352 png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; | 2996 PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; |
2353 png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; | 2997 PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; |
2354 png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; | 2998 PNG_CONST png_uint_32 bc = 32768 - rc - gc; |
2355 | 2999 PNG_CONST png_uint_32 row_width = row_info->width; |
2356 if (row_info->color_type == PNG_COLOR_TYPE_RGB) | 3000 PNG_CONST int have_alpha = |
| 3001 (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; |
| 3002 |
| 3003 if (row_info->bit_depth == 8) |
2357 { | 3004 { |
2358 if (row_info->bit_depth == 8) | 3005 #ifdef PNG_READ_GAMMA_SUPPORTED |
2359 { | 3006 /* Notice that gamma to/from 1 are not necessarily inverses (if |
2360 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) | 3007 * there is an overall gamma correction). Prior to 1.5.5 this code |
2361 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) | 3008 * checked the linearized values for equality; this doesn't match |
2362 { | 3009 * the documentation, the original values must be checked. |
2363 png_bytep sp = row; | 3010 */ |
2364 png_bytep dp = row; | 3011 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
2365 | 3012 { |
2366 for (i = 0; i < row_width; i++) | 3013 png_bytep sp = row; |
2367 { | 3014 png_bytep dp = row; |
2368 png_byte red = png_ptr->gamma_to_1[*(sp++)]; | 3015 png_uint_32 i; |
2369 png_byte green = png_ptr->gamma_to_1[*(sp++)]; | 3016 |
2370 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; | 3017 for (i = 0; i < row_width; i++) |
2371 if (red != green || red != blue) | 3018 { |
2372 { | 3019 png_byte red = *(sp++); |
2373 rgb_error |= 1; | 3020 png_byte green = *(sp++); |
2374 *(dp++) = png_ptr->gamma_from_1[ | 3021 png_byte blue = *(sp++); |
2375 (rc*red + gc*green + bc*blue)>>15]; | 3022 |
2376 } | 3023 if (red != green || red != blue) |
| 3024 { |
| 3025 red = png_ptr->gamma_to_1[red]; |
| 3026 green = png_ptr->gamma_to_1[green]; |
| 3027 blue = png_ptr->gamma_to_1[blue]; |
| 3028 |
| 3029 rgb_error |= 1; |
| 3030 *(dp++) = png_ptr->gamma_from_1[ |
| 3031 (rc*red + gc*green + bc*blue + 16384)>>15]; |
| 3032 } |
| 3033 |
| 3034 else |
| 3035 { |
| 3036 /* If there is no overall correction the table will not be |
| 3037 * set. |
| 3038 */ |
| 3039 if (png_ptr->gamma_table != NULL) |
| 3040 red = png_ptr->gamma_table[red]; |
| 3041 |
| 3042 *(dp++) = red; |
| 3043 } |
| 3044 |
| 3045 if (have_alpha != 0) |
| 3046 *(dp++) = *(sp++); |
| 3047 } |
| 3048 } |
| 3049 else |
| 3050 #endif |
| 3051 { |
| 3052 png_bytep sp = row; |
| 3053 png_bytep dp = row; |
| 3054 png_uint_32 i; |
| 3055 |
| 3056 for (i = 0; i < row_width; i++) |
| 3057 { |
| 3058 png_byte red = *(sp++); |
| 3059 png_byte green = *(sp++); |
| 3060 png_byte blue = *(sp++); |
| 3061 |
| 3062 if (red != green || red != blue) |
| 3063 { |
| 3064 rgb_error |= 1; |
| 3065 /* NOTE: this is the historical approach which simply |
| 3066 * truncates the results. |
| 3067 */ |
| 3068 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
| 3069 } |
| 3070 |
| 3071 else |
| 3072 *(dp++) = red; |
| 3073 |
| 3074 if (have_alpha != 0) |
| 3075 *(dp++) = *(sp++); |
| 3076 } |
| 3077 } |
| 3078 } |
| 3079 |
| 3080 else /* RGB bit_depth == 16 */ |
| 3081 { |
| 3082 #ifdef PNG_READ_GAMMA_SUPPORTED |
| 3083 if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) |
| 3084 { |
| 3085 png_bytep sp = row; |
| 3086 png_bytep dp = row; |
| 3087 png_uint_32 i; |
| 3088 |
| 3089 for (i = 0; i < row_width; i++) |
| 3090 { |
| 3091 png_uint_16 red, green, blue, w; |
| 3092 png_byte hi,lo; |
| 3093 |
| 3094 hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); |
| 3095 hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); |
| 3096 hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); |
| 3097 |
| 3098 if (red == green && red == blue) |
| 3099 { |
| 3100 if (png_ptr->gamma_16_table != NULL) |
| 3101 w = png_ptr->gamma_16_table[(red & 0xff) |
| 3102 >> png_ptr->gamma_shift][red >> 8]; |
| 3103 |
2377 else | 3104 else |
2378 *(dp++) = *(sp - 1); | |
2379 } | |
2380 } | |
2381 else | |
2382 #endif | |
2383 { | |
2384 png_bytep sp = row; | |
2385 png_bytep dp = row; | |
2386 for (i = 0; i < row_width; i++) | |
2387 { | |
2388 png_byte red = *(sp++); | |
2389 png_byte green = *(sp++); | |
2390 png_byte blue = *(sp++); | |
2391 if (red != green || red != blue) | |
2392 { | |
2393 rgb_error |= 1; | |
2394 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); | |
2395 } | |
2396 else | |
2397 *(dp++) = *(sp - 1); | |
2398 } | |
2399 } | |
2400 } | |
2401 | |
2402 else /* RGB bit_depth == 16 */ | |
2403 { | |
2404 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) | |
2405 if (png_ptr->gamma_16_to_1 != NULL && | |
2406 png_ptr->gamma_16_from_1 != NULL) | |
2407 { | |
2408 png_bytep sp = row; | |
2409 png_bytep dp = row; | |
2410 for (i = 0; i < row_width; i++) | |
2411 { | |
2412 png_uint_16 red, green, blue, w; | |
2413 png_byte hi,lo; | |
2414 | |
2415 hi=*(sp)++; lo=*(sp)++; | |
2416 red = (png_uint_16)((hi << 8) | (lo)); | |
2417 hi=*(sp)++; lo=*(sp)++; | |
2418 green = (png_uint_16)((hi << 8) | (lo)); | |
2419 hi=*(sp)++; lo=*(sp)++; | |
2420 blue = (png_uint_16)((hi << 8) | (lo)); | |
2421 | |
2422 if (red == green && red == blue) | |
2423 w = red; | 3105 w = red; |
2424 else | 3106 } |
2425 { | 3107 |
2426 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> | 3108 else |
2427 png_ptr->gamma_shift][red>>8]; | 3109 { |
2428 png_uint_16 green_1 = | 3110 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff) |
2429 png_ptr->gamma_16_to_1[(green&0xff) >> | 3111 >> png_ptr->gamma_shift][red>>8]; |
2430 png_ptr->gamma_shift][green>>8]; | 3112 png_uint_16 green_1 = |
2431 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> | 3113 png_ptr->gamma_16_to_1[(green & 0xff) >> |
2432 png_ptr->gamma_shift][blue>>8]; | 3114 png_ptr->gamma_shift][green>>8]; |
2433 png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 | 3115 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff) |
2434 + bc*blue_1)>>15); | 3116 >> png_ptr->gamma_shift][blue>>8]; |
2435 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> | 3117 png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 |
2436 png_ptr->gamma_shift][gray16 >> 8]; | 3118 + bc*blue_1 + 16384)>>15); |
2437 rgb_error |= 1; | 3119 w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >> |
2438 } | 3120 png_ptr->gamma_shift][gray16 >> 8]; |
2439 | 3121 rgb_error |= 1; |
2440 *(dp++) = (png_byte)((w>>8) & 0xff); | 3122 } |
2441 *(dp++) = (png_byte)(w & 0xff); | 3123 |
2442 } | 3124 *(dp++) = (png_byte)((w>>8) & 0xff); |
2443 } | 3125 *(dp++) = (png_byte)(w & 0xff); |
2444 else | 3126 |
2445 #endif | 3127 if (have_alpha != 0) |
2446 { | 3128 { |
2447 png_bytep sp = row; | 3129 *(dp++) = *(sp++); |
2448 png_bytep dp = row; | 3130 *(dp++) = *(sp++); |
2449 for (i = 0; i < row_width; i++) | 3131 } |
2450 { | 3132 } |
2451 png_uint_16 red, green, blue, gray16; | 3133 } |
2452 png_byte hi,lo; | 3134 else |
2453 | 3135 #endif |
2454 hi=*(sp)++; lo=*(sp)++; | 3136 { |
2455 red = (png_uint_16)((hi << 8) | (lo)); | 3137 png_bytep sp = row; |
2456 hi=*(sp)++; lo=*(sp)++; | 3138 png_bytep dp = row; |
2457 green = (png_uint_16)((hi << 8) | (lo)); | 3139 png_uint_32 i; |
2458 hi=*(sp)++; lo=*(sp)++; | 3140 |
2459 blue = (png_uint_16)((hi << 8) | (lo)); | 3141 for (i = 0; i < row_width; i++) |
2460 | 3142 { |
2461 if (red != green || red != blue) | 3143 png_uint_16 red, green, blue, gray16; |
2462 rgb_error |= 1; | 3144 png_byte hi,lo; |
2463 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); | 3145 |
2464 *(dp++) = (png_byte)((gray16>>8) & 0xff); | 3146 hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo)); |
2465 *(dp++) = (png_byte)(gray16 & 0xff); | 3147 hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo)); |
| 3148 hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo)); |
| 3149 |
| 3150 if (red != green || red != blue) |
| 3151 rgb_error |= 1; |
| 3152 |
| 3153 /* From 1.5.5 in the 16-bit case do the accurate conversion even |
| 3154 * in the 'fast' case - this is because this is where the code |
| 3155 * ends up when handling linear 16-bit data. |
| 3156 */ |
| 3157 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> |
| 3158 15); |
| 3159 *(dp++) = (png_byte)((gray16 >> 8) & 0xff); |
| 3160 *(dp++) = (png_byte)(gray16 & 0xff); |
| 3161 |
| 3162 if (have_alpha != 0) |
| 3163 { |
| 3164 *(dp++) = *(sp++); |
| 3165 *(dp++) = *(sp++); |
2466 } | 3166 } |
2467 } | 3167 } |
2468 } | 3168 } |
2469 } | 3169 } |
2470 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | 3170 |
2471 { | 3171 row_info->channels = (png_byte)(row_info->channels - 2); |
2472 if (row_info->bit_depth == 8) | 3172 row_info->color_type = (png_byte)(row_info->color_type & |
2473 { | 3173 ~PNG_COLOR_MASK_COLOR); |
2474 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) | |
2475 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) | |
2476 { | |
2477 png_bytep sp = row; | |
2478 png_bytep dp = row; | |
2479 for (i = 0; i < row_width; i++) | |
2480 { | |
2481 png_byte red = png_ptr->gamma_to_1[*(sp++)]; | |
2482 png_byte green = png_ptr->gamma_to_1[*(sp++)]; | |
2483 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; | |
2484 if (red != green || red != blue) | |
2485 rgb_error |= 1; | |
2486 *(dp++) = png_ptr->gamma_from_1 | |
2487 [(rc*red + gc*green + bc*blue)>>15]; | |
2488 *(dp++) = *(sp++); /* alpha */ | |
2489 } | |
2490 } | |
2491 else | |
2492 #endif | |
2493 { | |
2494 png_bytep sp = row; | |
2495 png_bytep dp = row; | |
2496 for (i = 0; i < row_width; i++) | |
2497 { | |
2498 png_byte red = *(sp++); | |
2499 png_byte green = *(sp++); | |
2500 png_byte blue = *(sp++); | |
2501 if (red != green || red != blue) | |
2502 rgb_error |= 1; | |
2503 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); | |
2504 *(dp++) = *(sp++); /* alpha */ | |
2505 } | |
2506 } | |
2507 } | |
2508 else /* RGBA bit_depth == 16 */ | |
2509 { | |
2510 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) | |
2511 if (png_ptr->gamma_16_to_1 != NULL && | |
2512 png_ptr->gamma_16_from_1 != NULL) | |
2513 { | |
2514 png_bytep sp = row; | |
2515 png_bytep dp = row; | |
2516 for (i = 0; i < row_width; i++) | |
2517 { | |
2518 png_uint_16 red, green, blue, w; | |
2519 png_byte hi,lo; | |
2520 | |
2521 hi=*(sp)++; lo=*(sp)++; | |
2522 red = (png_uint_16)((hi << 8) | (lo)); | |
2523 hi=*(sp)++; lo=*(sp)++; | |
2524 green = (png_uint_16)((hi << 8) | (lo)); | |
2525 hi=*(sp)++; lo=*(sp)++; | |
2526 blue = (png_uint_16)((hi << 8) | (lo)); | |
2527 | |
2528 if (red == green && red == blue) | |
2529 w = red; | |
2530 else | |
2531 { | |
2532 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> | |
2533 png_ptr->gamma_shift][red>>8]; | |
2534 png_uint_16 green_1 = | |
2535 png_ptr->gamma_16_to_1[(green&0xff) >> | |
2536 png_ptr->gamma_shift][green>>8]; | |
2537 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> | |
2538 png_ptr->gamma_shift][blue>>8]; | |
2539 png_uint_16 gray16 = (png_uint_16)((rc * red_1 | |
2540 + gc * green_1 + bc * blue_1)>>15); | |
2541 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> | |
2542 png_ptr->gamma_shift][gray16 >> 8]; | |
2543 rgb_error |= 1; | |
2544 } | |
2545 | |
2546 *(dp++) = (png_byte)((w>>8) & 0xff); | |
2547 *(dp++) = (png_byte)(w & 0xff); | |
2548 *(dp++) = *(sp++); /* alpha */ | |
2549 *(dp++) = *(sp++); | |
2550 } | |
2551 } | |
2552 else | |
2553 #endif | |
2554 { | |
2555 png_bytep sp = row; | |
2556 png_bytep dp = row; | |
2557 for (i = 0; i < row_width; i++) | |
2558 { | |
2559 png_uint_16 red, green, blue, gray16; | |
2560 red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; | |
2561 green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; | |
2562 blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; | |
2563 if (red != green || red != blue) | |
2564 rgb_error |= 1; | |
2565 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); | |
2566 *(dp++) = (png_byte)((gray16>>8) & 0xff); | |
2567 *(dp++) = (png_byte)(gray16 & 0xff); | |
2568 *(dp++) = *(sp++); /* alpha */ | |
2569 *(dp++) = *(sp++); | |
2570 } | |
2571 } | |
2572 } | |
2573 } | |
2574 row_info->channels -= (png_byte)2; | |
2575 row_info->color_type &= ~PNG_COLOR_MASK_COLOR; | |
2576 row_info->pixel_depth = (png_byte)(row_info->channels * | 3174 row_info->pixel_depth = (png_byte)(row_info->channels * |
2577 row_info->bit_depth); | 3175 row_info->bit_depth); |
2578 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | 3176 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
2579 } | 3177 } |
2580 return rgb_error; | 3178 return rgb_error; |
2581 } | 3179 } |
2582 #endif | 3180 #endif |
2583 | 3181 |
2584 /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth | 3182 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ |
2585 * large of png_color. This lets grayscale images be treated as | 3183 defined(PNG_READ_ALPHA_MODE_SUPPORTED) |
2586 * paletted. Most useful for gamma correction and simplification | |
2587 * of code. | |
2588 */ | |
2589 void PNGAPI | |
2590 png_build_grayscale_palette(int bit_depth, png_colorp palette) | |
2591 { | |
2592 int num_palette; | |
2593 int color_inc; | |
2594 int i; | |
2595 int v; | |
2596 | |
2597 png_debug(1, "in png_do_build_grayscale_palette"); | |
2598 | |
2599 if (palette == NULL) | |
2600 return; | |
2601 | |
2602 switch (bit_depth) | |
2603 { | |
2604 case 1: | |
2605 num_palette = 2; | |
2606 color_inc = 0xff; | |
2607 break; | |
2608 | |
2609 case 2: | |
2610 num_palette = 4; | |
2611 color_inc = 0x55; | |
2612 break; | |
2613 | |
2614 case 4: | |
2615 num_palette = 16; | |
2616 color_inc = 0x11; | |
2617 break; | |
2618 | |
2619 case 8: | |
2620 num_palette = 256; | |
2621 color_inc = 1; | |
2622 break; | |
2623 | |
2624 default: | |
2625 num_palette = 0; | |
2626 color_inc = 0; | |
2627 break; | |
2628 } | |
2629 | |
2630 for (i = 0, v = 0; i < num_palette; i++, v += color_inc) | |
2631 { | |
2632 palette[i].red = (png_byte)v; | |
2633 palette[i].green = (png_byte)v; | |
2634 palette[i].blue = (png_byte)v; | |
2635 } | |
2636 } | |
2637 | |
2638 /* This function is currently unused. Do we really need it? */ | |
2639 #if defined(PNG_READ_DITHER_SUPPORTED) && \ | |
2640 defined(PNG_CORRECT_PALETTE_SUPPORTED) | |
2641 void /* PRIVATE */ | |
2642 png_correct_palette(png_structp png_ptr, png_colorp palette, | |
2643 int num_palette) | |
2644 { | |
2645 png_debug(1, "in png_correct_palette"); | |
2646 | |
2647 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ | |
2648 defined(PNG_READ_GAMMA_SUPPORTED) && \ | |
2649 defined(PNG_FLOATING_POINT_SUPPORTED) | |
2650 if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND)) | |
2651 { | |
2652 png_color back, back_1; | |
2653 | |
2654 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) | |
2655 { | |
2656 back.red = png_ptr->gamma_table[png_ptr->background.red]; | |
2657 back.green = png_ptr->gamma_table[png_ptr->background.green]; | |
2658 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; | |
2659 | |
2660 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; | |
2661 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; | |
2662 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; | |
2663 } | |
2664 else | |
2665 { | |
2666 double g; | |
2667 | |
2668 g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); | |
2669 | |
2670 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN | |
2671 || fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) | |
2672 { | |
2673 back.red = png_ptr->background.red; | |
2674 back.green = png_ptr->background.green; | |
2675 back.blue = png_ptr->background.blue; | |
2676 } | |
2677 else | |
2678 { | |
2679 back.red = | |
2680 (png_byte)(pow((double)png_ptr->background.red/255, g) * | |
2681 255.0 + 0.5); | |
2682 back.green = | |
2683 (png_byte)(pow((double)png_ptr->background.green/255, g) * | |
2684 255.0 + 0.5); | |
2685 back.blue = | |
2686 (png_byte)(pow((double)png_ptr->background.blue/255, g) * | |
2687 255.0 + 0.5); | |
2688 } | |
2689 | |
2690 g = 1.0 / png_ptr->background_gamma; | |
2691 | |
2692 back_1.red = | |
2693 (png_byte)(pow((double)png_ptr->background.red/255, g) * | |
2694 255.0 + 0.5); | |
2695 back_1.green = | |
2696 (png_byte)(pow((double)png_ptr->background.green/255, g) * | |
2697 255.0 + 0.5); | |
2698 back_1.blue = | |
2699 (png_byte)(pow((double)png_ptr->background.blue/255, g) * | |
2700 255.0 + 0.5); | |
2701 } | |
2702 | |
2703 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
2704 { | |
2705 png_uint_32 i; | |
2706 | |
2707 for (i = 0; i < (png_uint_32)num_palette; i++) | |
2708 { | |
2709 if (i < png_ptr->num_trans && png_ptr->trans[i] == 0) | |
2710 { | |
2711 palette[i] = back; | |
2712 } | |
2713 else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff) | |
2714 { | |
2715 png_byte v, w; | |
2716 | |
2717 v = png_ptr->gamma_to_1[png_ptr->palette[i].red]; | |
2718 png_composite(w, v, png_ptr->trans[i], back_1.red); | |
2719 palette[i].red = png_ptr->gamma_from_1[w]; | |
2720 | |
2721 v = png_ptr->gamma_to_1[png_ptr->palette[i].green]; | |
2722 png_composite(w, v, png_ptr->trans[i], back_1.green); | |
2723 palette[i].green = png_ptr->gamma_from_1[w]; | |
2724 | |
2725 v = png_ptr->gamma_to_1[png_ptr->palette[i].blue]; | |
2726 png_composite(w, v, png_ptr->trans[i], back_1.blue); | |
2727 palette[i].blue = png_ptr->gamma_from_1[w]; | |
2728 } | |
2729 else | |
2730 { | |
2731 palette[i].red = png_ptr->gamma_table[palette[i].red]; | |
2732 palette[i].green = png_ptr->gamma_table[palette[i].green]; | |
2733 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; | |
2734 } | |
2735 } | |
2736 } | |
2737 else | |
2738 { | |
2739 int i; | |
2740 | |
2741 for (i = 0; i < num_palette; i++) | |
2742 { | |
2743 if (palette[i].red == (png_byte)png_ptr->trans_values.gray) | |
2744 { | |
2745 palette[i] = back; | |
2746 } | |
2747 else | |
2748 { | |
2749 palette[i].red = png_ptr->gamma_table[palette[i].red]; | |
2750 palette[i].green = png_ptr->gamma_table[palette[i].green]; | |
2751 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; | |
2752 } | |
2753 } | |
2754 } | |
2755 } | |
2756 else | |
2757 #endif | |
2758 #ifdef PNG_READ_GAMMA_SUPPORTED | |
2759 if (png_ptr->transformations & PNG_GAMMA) | |
2760 { | |
2761 int i; | |
2762 | |
2763 for (i = 0; i < num_palette; i++) | |
2764 { | |
2765 palette[i].red = png_ptr->gamma_table[palette[i].red]; | |
2766 palette[i].green = png_ptr->gamma_table[palette[i].green]; | |
2767 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; | |
2768 } | |
2769 } | |
2770 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
2771 else | |
2772 #endif | |
2773 #endif | |
2774 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
2775 if (png_ptr->transformations & PNG_BACKGROUND) | |
2776 { | |
2777 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) | |
2778 { | |
2779 png_color back; | |
2780 | |
2781 back.red = (png_byte)png_ptr->background.red; | |
2782 back.green = (png_byte)png_ptr->background.green; | |
2783 back.blue = (png_byte)png_ptr->background.blue; | |
2784 | |
2785 for (i = 0; i < (int)png_ptr->num_trans; i++) | |
2786 { | |
2787 if (png_ptr->trans[i] == 0) | |
2788 { | |
2789 palette[i].red = back.red; | |
2790 palette[i].green = back.green; | |
2791 palette[i].blue = back.blue; | |
2792 } | |
2793 else if (png_ptr->trans[i] != 0xff) | |
2794 { | |
2795 png_composite(palette[i].red, png_ptr->palette[i].red, | |
2796 png_ptr->trans[i], back.red); | |
2797 png_composite(palette[i].green, png_ptr->palette[i].green, | |
2798 png_ptr->trans[i], back.green); | |
2799 png_composite(palette[i].blue, png_ptr->palette[i].blue, | |
2800 png_ptr->trans[i], back.blue); | |
2801 } | |
2802 } | |
2803 } | |
2804 else /* Assume grayscale palette (what else could it be?) */ | |
2805 { | |
2806 int i; | |
2807 | |
2808 for (i = 0; i < num_palette; i++) | |
2809 { | |
2810 if (i == (png_byte)png_ptr->trans_values.gray) | |
2811 { | |
2812 palette[i].red = (png_byte)png_ptr->background.red; | |
2813 palette[i].green = (png_byte)png_ptr->background.green; | |
2814 palette[i].blue = (png_byte)png_ptr->background.blue; | |
2815 } | |
2816 } | |
2817 } | |
2818 } | |
2819 #endif | |
2820 } | |
2821 #endif | |
2822 | |
2823 #ifdef PNG_READ_BACKGROUND_SUPPORTED | |
2824 /* Replace any alpha or transparency with the supplied background color. | 3184 /* Replace any alpha or transparency with the supplied background color. |
2825 * "background" is already in the screen gamma, while "background_1" is | 3185 * "background" is already in the screen gamma, while "background_1" is |
2826 * at a gamma of 1.0. Paletted files have already been taken care of. | 3186 * at a gamma of 1.0. Paletted files have already been taken care of. |
2827 */ | 3187 */ |
2828 void /* PRIVATE */ | 3188 static void |
2829 png_do_background(png_row_infop row_info, png_bytep row, | 3189 png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr) |
2830 png_color_16p trans_values, png_color_16p background | 3190 { |
2831 #ifdef PNG_READ_GAMMA_SUPPORTED | 3191 #ifdef PNG_READ_GAMMA_SUPPORTED |
2832 , png_color_16p background_1, | 3192 png_const_bytep gamma_table = png_ptr->gamma_table; |
2833 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, | 3193 png_const_bytep gamma_from_1 = png_ptr->gamma_from_1; |
2834 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, | 3194 png_const_bytep gamma_to_1 = png_ptr->gamma_to_1; |
2835 png_uint_16pp gamma_16_to_1, int gamma_shift | 3195 png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table; |
2836 #endif | 3196 png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1; |
2837 ) | 3197 png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1; |
2838 { | 3198 int gamma_shift = png_ptr->gamma_shift; |
2839 png_bytep sp, dp; | 3199 int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0; |
| 3200 #endif |
| 3201 |
| 3202 png_bytep sp; |
2840 png_uint_32 i; | 3203 png_uint_32 i; |
2841 png_uint_32 row_width=row_info->width; | 3204 png_uint_32 row_width = row_info->width; |
2842 int shift; | 3205 int shift; |
2843 | 3206 |
2844 png_debug(1, "in png_do_background"); | 3207 png_debug(1, "in png_do_compose"); |
2845 | 3208 |
2846 if (background != NULL && | |
2847 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
2848 row != NULL && row_info != NULL && | |
2849 #endif | |
2850 (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || | |
2851 (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values))) | |
2852 { | 3209 { |
2853 switch (row_info->color_type) | 3210 switch (row_info->color_type) |
2854 { | 3211 { |
2855 case PNG_COLOR_TYPE_GRAY: | 3212 case PNG_COLOR_TYPE_GRAY: |
2856 { | 3213 { |
2857 switch (row_info->bit_depth) | 3214 switch (row_info->bit_depth) |
2858 { | 3215 { |
2859 case 1: | 3216 case 1: |
2860 { | 3217 { |
2861 sp = row; | 3218 sp = row; |
2862 shift = 7; | 3219 shift = 7; |
2863 for (i = 0; i < row_width; i++) | 3220 for (i = 0; i < row_width; i++) |
2864 { | 3221 { |
2865 if ((png_uint_16)((*sp >> shift) & 0x01) | 3222 if ((png_uint_16)((*sp >> shift) & 0x01) |
2866 == trans_values->gray) | 3223 == png_ptr->trans_color.gray) |
2867 { | 3224 { |
2868 *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); | 3225 unsigned int tmp = *sp & (0x7f7f >> (7 - shift)); |
2869 *sp |= (png_byte)(background->gray << shift); | 3226 tmp |= png_ptr->background.gray << shift; |
| 3227 *sp = (png_byte)(tmp & 0xff); |
2870 } | 3228 } |
2871 if (!shift) | 3229 |
| 3230 if (shift == 0) |
2872 { | 3231 { |
2873 shift = 7; | 3232 shift = 7; |
2874 sp++; | 3233 sp++; |
2875 } | 3234 } |
| 3235 |
2876 else | 3236 else |
2877 shift--; | 3237 shift--; |
2878 } | 3238 } |
2879 break; | 3239 break; |
2880 } | 3240 } |
2881 | 3241 |
2882 case 2: | 3242 case 2: |
2883 { | 3243 { |
2884 #ifdef PNG_READ_GAMMA_SUPPORTED | 3244 #ifdef PNG_READ_GAMMA_SUPPORTED |
2885 if (gamma_table != NULL) | 3245 if (gamma_table != NULL) |
2886 { | 3246 { |
2887 sp = row; | 3247 sp = row; |
2888 shift = 6; | 3248 shift = 6; |
2889 for (i = 0; i < row_width; i++) | 3249 for (i = 0; i < row_width; i++) |
2890 { | 3250 { |
2891 if ((png_uint_16)((*sp >> shift) & 0x03) | 3251 if ((png_uint_16)((*sp >> shift) & 0x03) |
2892 == trans_values->gray) | 3252 == png_ptr->trans_color.gray) |
2893 { | 3253 { |
2894 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); | 3254 unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); |
2895 *sp |= (png_byte)(background->gray << shift); | 3255 tmp |= png_ptr->background.gray << shift; |
| 3256 *sp = (png_byte)(tmp & 0xff); |
2896 } | 3257 } |
| 3258 |
2897 else | 3259 else |
2898 { | 3260 { |
2899 png_byte p = (png_byte)((*sp >> shift) & 0x03); | 3261 unsigned int p = (*sp >> shift) & 0x03; |
2900 png_byte g = (png_byte)((gamma_table [p | (p << 2) | | 3262 unsigned int g = (gamma_table [p | (p << 2) | |
2901 (p << 4) | (p << 6)] >> 6) & 0x03); | 3263 (p << 4) | (p << 6)] >> 6) & 0x03; |
2902 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); | 3264 unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); |
2903 *sp |= (png_byte)(g << shift); | 3265 tmp |= g << shift; |
| 3266 *sp = (png_byte)(tmp & 0xff); |
2904 } | 3267 } |
2905 if (!shift) | 3268 |
| 3269 if (shift == 0) |
2906 { | 3270 { |
2907 shift = 6; | 3271 shift = 6; |
2908 sp++; | 3272 sp++; |
2909 } | 3273 } |
| 3274 |
2910 else | 3275 else |
2911 shift -= 2; | 3276 shift -= 2; |
2912 } | 3277 } |
2913 } | 3278 } |
| 3279 |
2914 else | 3280 else |
2915 #endif | 3281 #endif |
2916 { | 3282 { |
2917 sp = row; | 3283 sp = row; |
2918 shift = 6; | 3284 shift = 6; |
2919 for (i = 0; i < row_width; i++) | 3285 for (i = 0; i < row_width; i++) |
2920 { | 3286 { |
2921 if ((png_uint_16)((*sp >> shift) & 0x03) | 3287 if ((png_uint_16)((*sp >> shift) & 0x03) |
2922 == trans_values->gray) | 3288 == png_ptr->trans_color.gray) |
2923 { | 3289 { |
2924 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); | 3290 unsigned int tmp = *sp & (0x3f3f >> (6 - shift)); |
2925 *sp |= (png_byte)(background->gray << shift); | 3291 tmp |= png_ptr->background.gray << shift; |
| 3292 *sp = (png_byte)(tmp & 0xff); |
2926 } | 3293 } |
2927 if (!shift) | 3294 |
| 3295 if (shift == 0) |
2928 { | 3296 { |
2929 shift = 6; | 3297 shift = 6; |
2930 sp++; | 3298 sp++; |
2931 } | 3299 } |
| 3300 |
2932 else | 3301 else |
2933 shift -= 2; | 3302 shift -= 2; |
2934 } | 3303 } |
2935 } | 3304 } |
2936 break; | 3305 break; |
2937 } | 3306 } |
2938 | 3307 |
2939 case 4: | 3308 case 4: |
2940 { | 3309 { |
2941 #ifdef PNG_READ_GAMMA_SUPPORTED | 3310 #ifdef PNG_READ_GAMMA_SUPPORTED |
2942 if (gamma_table != NULL) | 3311 if (gamma_table != NULL) |
2943 { | 3312 { |
2944 sp = row; | 3313 sp = row; |
2945 shift = 4; | 3314 shift = 4; |
2946 for (i = 0; i < row_width; i++) | 3315 for (i = 0; i < row_width; i++) |
2947 { | 3316 { |
2948 if ((png_uint_16)((*sp >> shift) & 0x0f) | 3317 if ((png_uint_16)((*sp >> shift) & 0x0f) |
2949 == trans_values->gray) | 3318 == png_ptr->trans_color.gray) |
2950 { | 3319 { |
2951 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); | 3320 unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); |
2952 *sp |= (png_byte)(background->gray << shift); | 3321 tmp |= png_ptr->background.gray << shift; |
| 3322 *sp = (png_byte)(tmp & 0xff); |
2953 } | 3323 } |
| 3324 |
2954 else | 3325 else |
2955 { | 3326 { |
2956 png_byte p = (png_byte)((*sp >> shift) & 0x0f); | 3327 unsigned int p = (*sp >> shift) & 0x0f; |
2957 png_byte g = (png_byte)((gamma_table[p | | 3328 unsigned int g = (gamma_table[p | (p << 4)] >> 4) & |
2958 (p << 4)] >> 4) & 0x0f); | 3329 0x0f; |
2959 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); | 3330 unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); |
2960 *sp |= (png_byte)(g << shift); | 3331 tmp |= g << shift; |
| 3332 *sp = (png_byte)(tmp & 0xff); |
2961 } | 3333 } |
2962 if (!shift) | 3334 |
| 3335 if (shift == 0) |
2963 { | 3336 { |
2964 shift = 4; | 3337 shift = 4; |
2965 sp++; | 3338 sp++; |
2966 } | 3339 } |
| 3340 |
2967 else | 3341 else |
2968 shift -= 4; | 3342 shift -= 4; |
2969 } | 3343 } |
2970 } | 3344 } |
| 3345 |
2971 else | 3346 else |
2972 #endif | 3347 #endif |
2973 { | 3348 { |
2974 sp = row; | 3349 sp = row; |
2975 shift = 4; | 3350 shift = 4; |
2976 for (i = 0; i < row_width; i++) | 3351 for (i = 0; i < row_width; i++) |
2977 { | 3352 { |
2978 if ((png_uint_16)((*sp >> shift) & 0x0f) | 3353 if ((png_uint_16)((*sp >> shift) & 0x0f) |
2979 == trans_values->gray) | 3354 == png_ptr->trans_color.gray) |
2980 { | 3355 { |
2981 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); | 3356 unsigned int tmp = *sp & (0x0f0f >> (4 - shift)); |
2982 *sp |= (png_byte)(background->gray << shift); | 3357 tmp |= png_ptr->background.gray << shift; |
| 3358 *sp = (png_byte)(tmp & 0xff); |
2983 } | 3359 } |
2984 if (!shift) | 3360 |
| 3361 if (shift == 0) |
2985 { | 3362 { |
2986 shift = 4; | 3363 shift = 4; |
2987 sp++; | 3364 sp++; |
2988 } | 3365 } |
| 3366 |
2989 else | 3367 else |
2990 shift -= 4; | 3368 shift -= 4; |
2991 } | 3369 } |
2992 } | 3370 } |
2993 break; | 3371 break; |
2994 } | 3372 } |
2995 | 3373 |
2996 case 8: | 3374 case 8: |
2997 { | 3375 { |
2998 #ifdef PNG_READ_GAMMA_SUPPORTED | 3376 #ifdef PNG_READ_GAMMA_SUPPORTED |
2999 if (gamma_table != NULL) | 3377 if (gamma_table != NULL) |
3000 { | 3378 { |
3001 sp = row; | 3379 sp = row; |
3002 for (i = 0; i < row_width; i++, sp++) | 3380 for (i = 0; i < row_width; i++, sp++) |
3003 { | 3381 { |
3004 if (*sp == trans_values->gray) | 3382 if (*sp == png_ptr->trans_color.gray) |
3005 { | 3383 *sp = (png_byte)png_ptr->background.gray; |
3006 *sp = (png_byte)background->gray; | 3384 |
3007 } | |
3008 else | 3385 else |
3009 { | |
3010 *sp = gamma_table[*sp]; | 3386 *sp = gamma_table[*sp]; |
3011 } | |
3012 } | 3387 } |
3013 } | 3388 } |
3014 else | 3389 else |
3015 #endif | 3390 #endif |
3016 { | 3391 { |
3017 sp = row; | 3392 sp = row; |
3018 for (i = 0; i < row_width; i++, sp++) | 3393 for (i = 0; i < row_width; i++, sp++) |
3019 { | 3394 { |
3020 if (*sp == trans_values->gray) | 3395 if (*sp == png_ptr->trans_color.gray) |
3021 { | 3396 *sp = (png_byte)png_ptr->background.gray; |
3022 *sp = (png_byte)background->gray; | |
3023 } | |
3024 } | 3397 } |
3025 } | 3398 } |
3026 break; | 3399 break; |
3027 } | 3400 } |
3028 | 3401 |
3029 case 16: | 3402 case 16: |
3030 { | 3403 { |
3031 #ifdef PNG_READ_GAMMA_SUPPORTED | 3404 #ifdef PNG_READ_GAMMA_SUPPORTED |
3032 if (gamma_16 != NULL) | 3405 if (gamma_16 != NULL) |
3033 { | 3406 { |
3034 sp = row; | 3407 sp = row; |
3035 for (i = 0; i < row_width; i++, sp += 2) | 3408 for (i = 0; i < row_width; i++, sp += 2) |
3036 { | 3409 { |
3037 png_uint_16 v; | 3410 png_uint_16 v; |
3038 | 3411 |
3039 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | 3412 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
3040 if (v == trans_values->gray) | 3413 |
| 3414 if (v == png_ptr->trans_color.gray) |
3041 { | 3415 { |
3042 /* Background is already in screen gamma */ | 3416 /* Background is already in screen gamma */ |
3043 *sp = (png_byte)((background->gray >> 8) & 0xff); | 3417 *sp = (png_byte)((png_ptr->background.gray >> 8) |
3044 *(sp + 1) = (png_byte)(background->gray & 0xff); | 3418 & 0xff); |
| 3419 *(sp + 1) = (png_byte)(png_ptr->background.gray |
| 3420 & 0xff); |
3045 } | 3421 } |
| 3422 |
3046 else | 3423 else |
3047 { | 3424 { |
3048 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | 3425 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
3049 *sp = (png_byte)((v >> 8) & 0xff); | 3426 *sp = (png_byte)((v >> 8) & 0xff); |
3050 *(sp + 1) = (png_byte)(v & 0xff); | 3427 *(sp + 1) = (png_byte)(v & 0xff); |
3051 } | 3428 } |
3052 } | 3429 } |
3053 } | 3430 } |
3054 else | 3431 else |
3055 #endif | 3432 #endif |
3056 { | 3433 { |
3057 sp = row; | 3434 sp = row; |
3058 for (i = 0; i < row_width; i++, sp += 2) | 3435 for (i = 0; i < row_width; i++, sp += 2) |
3059 { | 3436 { |
3060 png_uint_16 v; | 3437 png_uint_16 v; |
3061 | 3438 |
3062 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | 3439 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
3063 if (v == trans_values->gray) | 3440 |
| 3441 if (v == png_ptr->trans_color.gray) |
3064 { | 3442 { |
3065 *sp = (png_byte)((background->gray >> 8) & 0xff); | 3443 *sp = (png_byte)((png_ptr->background.gray >> 8) |
3066 *(sp + 1) = (png_byte)(background->gray & 0xff); | 3444 & 0xff); |
| 3445 *(sp + 1) = (png_byte)(png_ptr->background.gray |
| 3446 & 0xff); |
3067 } | 3447 } |
3068 } | 3448 } |
3069 } | 3449 } |
3070 break; | 3450 break; |
3071 } | 3451 } |
| 3452 |
| 3453 default: |
| 3454 break; |
3072 } | 3455 } |
3073 break; | 3456 break; |
3074 } | 3457 } |
3075 | 3458 |
3076 case PNG_COLOR_TYPE_RGB: | 3459 case PNG_COLOR_TYPE_RGB: |
3077 { | 3460 { |
3078 if (row_info->bit_depth == 8) | 3461 if (row_info->bit_depth == 8) |
3079 { | 3462 { |
3080 #ifdef PNG_READ_GAMMA_SUPPORTED | 3463 #ifdef PNG_READ_GAMMA_SUPPORTED |
3081 if (gamma_table != NULL) | 3464 if (gamma_table != NULL) |
3082 { | 3465 { |
3083 sp = row; | 3466 sp = row; |
3084 for (i = 0; i < row_width; i++, sp += 3) | 3467 for (i = 0; i < row_width; i++, sp += 3) |
3085 { | 3468 { |
3086 if (*sp == trans_values->red && | 3469 if (*sp == png_ptr->trans_color.red && |
3087 *(sp + 1) == trans_values->green && | 3470 *(sp + 1) == png_ptr->trans_color.green && |
3088 *(sp + 2) == trans_values->blue) | 3471 *(sp + 2) == png_ptr->trans_color.blue) |
3089 { | 3472 { |
3090 *sp = (png_byte)background->red; | 3473 *sp = (png_byte)png_ptr->background.red; |
3091 *(sp + 1) = (png_byte)background->green; | 3474 *(sp + 1) = (png_byte)png_ptr->background.green; |
3092 *(sp + 2) = (png_byte)background->blue; | 3475 *(sp + 2) = (png_byte)png_ptr->background.blue; |
3093 } | 3476 } |
| 3477 |
3094 else | 3478 else |
3095 { | 3479 { |
3096 *sp = gamma_table[*sp]; | 3480 *sp = gamma_table[*sp]; |
3097 *(sp + 1) = gamma_table[*(sp + 1)]; | 3481 *(sp + 1) = gamma_table[*(sp + 1)]; |
3098 *(sp + 2) = gamma_table[*(sp + 2)]; | 3482 *(sp + 2) = gamma_table[*(sp + 2)]; |
3099 } | 3483 } |
3100 } | 3484 } |
3101 } | 3485 } |
3102 else | 3486 else |
3103 #endif | 3487 #endif |
3104 { | 3488 { |
3105 sp = row; | 3489 sp = row; |
3106 for (i = 0; i < row_width; i++, sp += 3) | 3490 for (i = 0; i < row_width; i++, sp += 3) |
3107 { | 3491 { |
3108 if (*sp == trans_values->red && | 3492 if (*sp == png_ptr->trans_color.red && |
3109 *(sp + 1) == trans_values->green && | 3493 *(sp + 1) == png_ptr->trans_color.green && |
3110 *(sp + 2) == trans_values->blue) | 3494 *(sp + 2) == png_ptr->trans_color.blue) |
3111 { | 3495 { |
3112 *sp = (png_byte)background->red; | 3496 *sp = (png_byte)png_ptr->background.red; |
3113 *(sp + 1) = (png_byte)background->green; | 3497 *(sp + 1) = (png_byte)png_ptr->background.green; |
3114 *(sp + 2) = (png_byte)background->blue; | 3498 *(sp + 2) = (png_byte)png_ptr->background.blue; |
3115 } | 3499 } |
3116 } | 3500 } |
3117 } | 3501 } |
3118 } | 3502 } |
3119 else /* if (row_info->bit_depth == 16) */ | 3503 else /* if (row_info->bit_depth == 16) */ |
3120 { | 3504 { |
3121 #ifdef PNG_READ_GAMMA_SUPPORTED | 3505 #ifdef PNG_READ_GAMMA_SUPPORTED |
3122 if (gamma_16 != NULL) | 3506 if (gamma_16 != NULL) |
3123 { | 3507 { |
3124 sp = row; | 3508 sp = row; |
3125 for (i = 0; i < row_width; i++, sp += 6) | 3509 for (i = 0; i < row_width; i++, sp += 6) |
3126 { | 3510 { |
3127 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | 3511 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
3128 png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); | 3512 |
3129 png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); | 3513 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
3130 if (r == trans_values->red && g == trans_values->green && | 3514 + *(sp + 3)); |
3131 b == trans_values->blue) | 3515 |
| 3516 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
| 3517 + *(sp + 5)); |
| 3518 |
| 3519 if (r == png_ptr->trans_color.red && |
| 3520 g == png_ptr->trans_color.green && |
| 3521 b == png_ptr->trans_color.blue) |
3132 { | 3522 { |
3133 /* Background is already in screen gamma */ | 3523 /* Background is already in screen gamma */ |
3134 *sp = (png_byte)((background->red >> 8) & 0xff); | 3524 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
3135 *(sp + 1) = (png_byte)(background->red & 0xff); | 3525 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
3136 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); | 3526 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) |
3137 *(sp + 3) = (png_byte)(background->green & 0xff); | 3527 & 0xff); |
3138 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); | 3528 *(sp + 3) = (png_byte)(png_ptr->background.green |
3139 *(sp + 5) = (png_byte)(background->blue & 0xff); | 3529 & 0xff); |
| 3530 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) |
| 3531 & 0xff); |
| 3532 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
3140 } | 3533 } |
| 3534 |
3141 else | 3535 else |
3142 { | 3536 { |
3143 png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | 3537 png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
3144 *sp = (png_byte)((v >> 8) & 0xff); | 3538 *sp = (png_byte)((v >> 8) & 0xff); |
3145 *(sp + 1) = (png_byte)(v & 0xff); | 3539 *(sp + 1) = (png_byte)(v & 0xff); |
| 3540 |
3146 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; | 3541 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
3147 *(sp + 2) = (png_byte)((v >> 8) & 0xff); | 3542 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
3148 *(sp + 3) = (png_byte)(v & 0xff); | 3543 *(sp + 3) = (png_byte)(v & 0xff); |
| 3544 |
3149 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; | 3545 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
3150 *(sp + 4) = (png_byte)((v >> 8) & 0xff); | 3546 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
3151 *(sp + 5) = (png_byte)(v & 0xff); | 3547 *(sp + 5) = (png_byte)(v & 0xff); |
3152 } | 3548 } |
3153 } | 3549 } |
3154 } | 3550 } |
| 3551 |
3155 else | 3552 else |
3156 #endif | 3553 #endif |
3157 { | 3554 { |
3158 sp = row; | 3555 sp = row; |
3159 for (i = 0; i < row_width; i++, sp += 6) | 3556 for (i = 0; i < row_width; i++, sp += 6) |
3160 { | 3557 { |
3161 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1)); | 3558 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
3162 png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); | |
3163 png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); | |
3164 | 3559 |
3165 if (r == trans_values->red && g == trans_values->green && | 3560 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
3166 b == trans_values->blue) | 3561 + *(sp + 3)); |
| 3562 |
| 3563 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
| 3564 + *(sp + 5)); |
| 3565 |
| 3566 if (r == png_ptr->trans_color.red && |
| 3567 g == png_ptr->trans_color.green && |
| 3568 b == png_ptr->trans_color.blue) |
3167 { | 3569 { |
3168 *sp = (png_byte)((background->red >> 8) & 0xff); | 3570 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
3169 *(sp + 1) = (png_byte)(background->red & 0xff); | 3571 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
3170 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); | 3572 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) |
3171 *(sp + 3) = (png_byte)(background->green & 0xff); | 3573 & 0xff); |
3172 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); | 3574 *(sp + 3) = (png_byte)(png_ptr->background.green |
3173 *(sp + 5) = (png_byte)(background->blue & 0xff); | 3575 & 0xff); |
| 3576 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) |
| 3577 & 0xff); |
| 3578 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
3174 } | 3579 } |
3175 } | 3580 } |
3176 } | 3581 } |
3177 } | 3582 } |
3178 break; | 3583 break; |
3179 } | 3584 } |
3180 | 3585 |
3181 case PNG_COLOR_TYPE_GRAY_ALPHA: | 3586 case PNG_COLOR_TYPE_GRAY_ALPHA: |
3182 { | 3587 { |
3183 if (row_info->bit_depth == 8) | 3588 if (row_info->bit_depth == 8) |
3184 { | 3589 { |
3185 #ifdef PNG_READ_GAMMA_SUPPORTED | 3590 #ifdef PNG_READ_GAMMA_SUPPORTED |
3186 if (gamma_to_1 != NULL && gamma_from_1 != NULL && | 3591 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
3187 gamma_table != NULL) | 3592 gamma_table != NULL) |
3188 { | 3593 { |
3189 sp = row; | 3594 sp = row; |
3190 dp = row; | 3595 for (i = 0; i < row_width; i++, sp += 2) |
3191 for (i = 0; i < row_width; i++, sp += 2, dp++) | |
3192 { | 3596 { |
3193 png_uint_16 a = *(sp + 1); | 3597 png_uint_16 a = *(sp + 1); |
3194 | 3598 |
3195 if (a == 0xff) | 3599 if (a == 0xff) |
3196 { | 3600 *sp = gamma_table[*sp]; |
3197 *dp = gamma_table[*sp]; | 3601 |
3198 } | |
3199 else if (a == 0) | 3602 else if (a == 0) |
3200 { | 3603 { |
3201 /* Background is already in screen gamma */ | 3604 /* Background is already in screen gamma */ |
3202 *dp = (png_byte)background->gray; | 3605 *sp = (png_byte)png_ptr->background.gray; |
3203 } | 3606 } |
| 3607 |
3204 else | 3608 else |
3205 { | 3609 { |
3206 png_byte v, w; | 3610 png_byte v, w; |
3207 | 3611 |
3208 v = gamma_to_1[*sp]; | 3612 v = gamma_to_1[*sp]; |
3209 png_composite(w, v, a, background_1->gray); | 3613 png_composite(w, v, a, png_ptr->background_1.gray); |
3210 *dp = gamma_from_1[w]; | 3614 if (optimize == 0) |
| 3615 w = gamma_from_1[w]; |
| 3616 *sp = w; |
3211 } | 3617 } |
3212 } | 3618 } |
3213 } | 3619 } |
3214 else | 3620 else |
3215 #endif | 3621 #endif |
3216 { | 3622 { |
3217 sp = row; | 3623 sp = row; |
3218 dp = row; | 3624 for (i = 0; i < row_width; i++, sp += 2) |
3219 for (i = 0; i < row_width; i++, sp += 2, dp++) | |
3220 { | 3625 { |
3221 png_byte a = *(sp + 1); | 3626 png_byte a = *(sp + 1); |
3222 | 3627 |
3223 if (a == 0xff) | 3628 if (a == 0) |
3224 { | 3629 *sp = (png_byte)png_ptr->background.gray; |
3225 *dp = *sp; | 3630 |
3226 } | 3631 else if (a < 0xff) |
3227 #ifdef PNG_READ_GAMMA_SUPPORTED | 3632 png_composite(*sp, *sp, a, png_ptr->background.gray); |
3228 else if (a == 0) | |
3229 { | |
3230 *dp = (png_byte)background->gray; | |
3231 } | |
3232 else | |
3233 { | |
3234 png_composite(*dp, *sp, a, background_1->gray); | |
3235 } | |
3236 #else | |
3237 *dp = (png_byte)background->gray; | |
3238 #endif | |
3239 } | 3633 } |
3240 } | 3634 } |
3241 } | 3635 } |
3242 else /* if (png_ptr->bit_depth == 16) */ | 3636 else /* if (png_ptr->bit_depth == 16) */ |
3243 { | 3637 { |
3244 #ifdef PNG_READ_GAMMA_SUPPORTED | 3638 #ifdef PNG_READ_GAMMA_SUPPORTED |
3245 if (gamma_16 != NULL && gamma_16_from_1 != NULL && | 3639 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
3246 gamma_16_to_1 != NULL) | 3640 gamma_16_to_1 != NULL) |
3247 { | 3641 { |
3248 sp = row; | 3642 sp = row; |
3249 dp = row; | 3643 for (i = 0; i < row_width; i++, sp += 4) |
3250 for (i = 0; i < row_width; i++, sp += 4, dp += 2) | |
3251 { | 3644 { |
3252 png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); | 3645 png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) |
| 3646 + *(sp + 3)); |
3253 | 3647 |
3254 if (a == (png_uint_16)0xffff) | 3648 if (a == (png_uint_16)0xffff) |
3255 { | 3649 { |
3256 png_uint_16 v; | 3650 png_uint_16 v; |
3257 | 3651 |
3258 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | 3652 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
3259 *dp = (png_byte)((v >> 8) & 0xff); | 3653 *sp = (png_byte)((v >> 8) & 0xff); |
3260 *(dp + 1) = (png_byte)(v & 0xff); | 3654 *(sp + 1) = (png_byte)(v & 0xff); |
3261 } | 3655 } |
3262 #ifdef PNG_READ_GAMMA_SUPPORTED | 3656 |
3263 else if (a == 0) | 3657 else if (a == 0) |
3264 #else | |
3265 else | |
3266 #endif | |
3267 { | 3658 { |
3268 /* Background is already in screen gamma */ | 3659 /* Background is already in screen gamma */ |
3269 *dp = (png_byte)((background->gray >> 8) & 0xff); | 3660 *sp = (png_byte)((png_ptr->background.gray >> 8) |
3270 *(dp + 1) = (png_byte)(background->gray & 0xff); | 3661 & 0xff); |
| 3662 *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); |
3271 } | 3663 } |
3272 #ifdef PNG_READ_GAMMA_SUPPORTED | 3664 |
3273 else | 3665 else |
3274 { | 3666 { |
3275 png_uint_16 g, v, w; | 3667 png_uint_16 g, v, w; |
3276 | 3668 |
3277 g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; | 3669 g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
3278 png_composite_16(v, g, a, background_1->gray); | 3670 png_composite_16(v, g, a, png_ptr->background_1.gray); |
3279 w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; | 3671 if (optimize != 0) |
3280 *dp = (png_byte)((w >> 8) & 0xff); | 3672 w = v; |
3281 *(dp + 1) = (png_byte)(w & 0xff); | 3673 else |
| 3674 w = gamma_16_from_1[(v & 0xff) >> |
| 3675 gamma_shift][v >> 8]; |
| 3676 *sp = (png_byte)((w >> 8) & 0xff); |
| 3677 *(sp + 1) = (png_byte)(w & 0xff); |
3282 } | 3678 } |
3283 #endif | |
3284 } | 3679 } |
3285 } | 3680 } |
3286 else | 3681 else |
3287 #endif | 3682 #endif |
3288 { | 3683 { |
3289 sp = row; | 3684 sp = row; |
3290 dp = row; | 3685 for (i = 0; i < row_width; i++, sp += 4) |
3291 for (i = 0; i < row_width; i++, sp += 4, dp += 2) | |
3292 { | 3686 { |
3293 png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); | 3687 png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8) |
3294 if (a == (png_uint_16)0xffff) | 3688 + *(sp + 3)); |
| 3689 |
| 3690 if (a == 0) |
3295 { | 3691 { |
3296 png_memcpy(dp, sp, 2); | 3692 *sp = (png_byte)((png_ptr->background.gray >> 8) |
| 3693 & 0xff); |
| 3694 *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff); |
3297 } | 3695 } |
3298 #ifdef PNG_READ_GAMMA_SUPPORTED | 3696 |
3299 else if (a == 0) | 3697 else if (a < 0xffff) |
3300 #else | |
3301 else | |
3302 #endif | |
3303 { | |
3304 *dp = (png_byte)((background->gray >> 8) & 0xff); | |
3305 *(dp + 1) = (png_byte)(background->gray & 0xff); | |
3306 } | |
3307 #ifdef PNG_READ_GAMMA_SUPPORTED | |
3308 else | |
3309 { | 3698 { |
3310 png_uint_16 g, v; | 3699 png_uint_16 g, v; |
3311 | 3700 |
3312 g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | 3701 g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
3313 png_composite_16(v, g, a, background_1->gray); | 3702 png_composite_16(v, g, a, png_ptr->background.gray); |
3314 *dp = (png_byte)((v >> 8) & 0xff); | 3703 *sp = (png_byte)((v >> 8) & 0xff); |
3315 *(dp + 1) = (png_byte)(v & 0xff); | 3704 *(sp + 1) = (png_byte)(v & 0xff); |
3316 } | 3705 } |
3317 #endif | |
3318 } | 3706 } |
3319 } | 3707 } |
3320 } | 3708 } |
3321 break; | 3709 break; |
3322 } | 3710 } |
3323 | 3711 |
3324 case PNG_COLOR_TYPE_RGB_ALPHA: | 3712 case PNG_COLOR_TYPE_RGB_ALPHA: |
3325 { | 3713 { |
3326 if (row_info->bit_depth == 8) | 3714 if (row_info->bit_depth == 8) |
3327 { | 3715 { |
3328 #ifdef PNG_READ_GAMMA_SUPPORTED | 3716 #ifdef PNG_READ_GAMMA_SUPPORTED |
3329 if (gamma_to_1 != NULL && gamma_from_1 != NULL && | 3717 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
3330 gamma_table != NULL) | 3718 gamma_table != NULL) |
3331 { | 3719 { |
3332 sp = row; | 3720 sp = row; |
3333 dp = row; | 3721 for (i = 0; i < row_width; i++, sp += 4) |
3334 for (i = 0; i < row_width; i++, sp += 4, dp += 3) | |
3335 { | 3722 { |
3336 png_byte a = *(sp + 3); | 3723 png_byte a = *(sp + 3); |
3337 | 3724 |
3338 if (a == 0xff) | 3725 if (a == 0xff) |
3339 { | 3726 { |
3340 *dp = gamma_table[*sp]; | 3727 *sp = gamma_table[*sp]; |
3341 *(dp + 1) = gamma_table[*(sp + 1)]; | 3728 *(sp + 1) = gamma_table[*(sp + 1)]; |
3342 *(dp + 2) = gamma_table[*(sp + 2)]; | 3729 *(sp + 2) = gamma_table[*(sp + 2)]; |
3343 } | 3730 } |
| 3731 |
3344 else if (a == 0) | 3732 else if (a == 0) |
3345 { | 3733 { |
3346 /* Background is already in screen gamma */ | 3734 /* Background is already in screen gamma */ |
3347 *dp = (png_byte)background->red; | 3735 *sp = (png_byte)png_ptr->background.red; |
3348 *(dp + 1) = (png_byte)background->green; | 3736 *(sp + 1) = (png_byte)png_ptr->background.green; |
3349 *(dp + 2) = (png_byte)background->blue; | 3737 *(sp + 2) = (png_byte)png_ptr->background.blue; |
3350 } | 3738 } |
| 3739 |
3351 else | 3740 else |
3352 { | 3741 { |
3353 png_byte v, w; | 3742 png_byte v, w; |
3354 | 3743 |
3355 v = gamma_to_1[*sp]; | 3744 v = gamma_to_1[*sp]; |
3356 png_composite(w, v, a, background_1->red); | 3745 png_composite(w, v, a, png_ptr->background_1.red); |
3357 *dp = gamma_from_1[w]; | 3746 if (optimize == 0) w = gamma_from_1[w]; |
| 3747 *sp = w; |
| 3748 |
3358 v = gamma_to_1[*(sp + 1)]; | 3749 v = gamma_to_1[*(sp + 1)]; |
3359 png_composite(w, v, a, background_1->green); | 3750 png_composite(w, v, a, png_ptr->background_1.green); |
3360 *(dp + 1) = gamma_from_1[w]; | 3751 if (optimize == 0) w = gamma_from_1[w]; |
| 3752 *(sp + 1) = w; |
| 3753 |
3361 v = gamma_to_1[*(sp + 2)]; | 3754 v = gamma_to_1[*(sp + 2)]; |
3362 png_composite(w, v, a, background_1->blue); | 3755 png_composite(w, v, a, png_ptr->background_1.blue); |
3363 *(dp + 2) = gamma_from_1[w]; | 3756 if (optimize == 0) w = gamma_from_1[w]; |
| 3757 *(sp + 2) = w; |
3364 } | 3758 } |
3365 } | 3759 } |
3366 } | 3760 } |
3367 else | 3761 else |
3368 #endif | 3762 #endif |
3369 { | 3763 { |
3370 sp = row; | 3764 sp = row; |
3371 dp = row; | 3765 for (i = 0; i < row_width; i++, sp += 4) |
3372 for (i = 0; i < row_width; i++, sp += 4, dp += 3) | |
3373 { | 3766 { |
3374 png_byte a = *(sp + 3); | 3767 png_byte a = *(sp + 3); |
3375 | 3768 |
3376 if (a == 0xff) | 3769 if (a == 0) |
3377 { | 3770 { |
3378 *dp = *sp; | 3771 *sp = (png_byte)png_ptr->background.red; |
3379 *(dp + 1) = *(sp + 1); | 3772 *(sp + 1) = (png_byte)png_ptr->background.green; |
3380 *(dp + 2) = *(sp + 2); | 3773 *(sp + 2) = (png_byte)png_ptr->background.blue; |
3381 } | 3774 } |
3382 else if (a == 0) | 3775 |
| 3776 else if (a < 0xff) |
3383 { | 3777 { |
3384 *dp = (png_byte)background->red; | 3778 png_composite(*sp, *sp, a, png_ptr->background.red); |
3385 *(dp + 1) = (png_byte)background->green; | 3779 |
3386 *(dp + 2) = (png_byte)background->blue; | 3780 png_composite(*(sp + 1), *(sp + 1), a, |
3387 } | 3781 png_ptr->background.green); |
3388 else | 3782 |
3389 { | 3783 png_composite(*(sp + 2), *(sp + 2), a, |
3390 png_composite(*dp, *sp, a, background->red); | 3784 png_ptr->background.blue); |
3391 png_composite(*(dp + 1), *(sp + 1), a, | |
3392 background->green); | |
3393 png_composite(*(dp + 2), *(sp + 2), a, | |
3394 background->blue); | |
3395 } | 3785 } |
3396 } | 3786 } |
3397 } | 3787 } |
3398 } | 3788 } |
3399 else /* if (row_info->bit_depth == 16) */ | 3789 else /* if (row_info->bit_depth == 16) */ |
3400 { | 3790 { |
3401 #ifdef PNG_READ_GAMMA_SUPPORTED | 3791 #ifdef PNG_READ_GAMMA_SUPPORTED |
3402 if (gamma_16 != NULL && gamma_16_from_1 != NULL && | 3792 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
3403 gamma_16_to_1 != NULL) | 3793 gamma_16_to_1 != NULL) |
3404 { | 3794 { |
3405 sp = row; | 3795 sp = row; |
3406 dp = row; | 3796 for (i = 0; i < row_width; i++, sp += 8) |
3407 for (i = 0; i < row_width; i++, sp += 8, dp += 6) | |
3408 { | 3797 { |
3409 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) | 3798 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
3410 << 8) + (png_uint_16)(*(sp + 7))); | 3799 << 8) + (png_uint_16)(*(sp + 7))); |
| 3800 |
3411 if (a == (png_uint_16)0xffff) | 3801 if (a == (png_uint_16)0xffff) |
3412 { | 3802 { |
3413 png_uint_16 v; | 3803 png_uint_16 v; |
3414 | 3804 |
3415 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; | 3805 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
3416 *dp = (png_byte)((v >> 8) & 0xff); | 3806 *sp = (png_byte)((v >> 8) & 0xff); |
3417 *(dp + 1) = (png_byte)(v & 0xff); | 3807 *(sp + 1) = (png_byte)(v & 0xff); |
| 3808 |
3418 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; | 3809 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
3419 *(dp + 2) = (png_byte)((v >> 8) & 0xff); | 3810 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
3420 *(dp + 3) = (png_byte)(v & 0xff); | 3811 *(sp + 3) = (png_byte)(v & 0xff); |
| 3812 |
3421 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; | 3813 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
3422 *(dp + 4) = (png_byte)((v >> 8) & 0xff); | 3814 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
3423 *(dp + 5) = (png_byte)(v & 0xff); | 3815 *(sp + 5) = (png_byte)(v & 0xff); |
3424 } | 3816 } |
| 3817 |
3425 else if (a == 0) | 3818 else if (a == 0) |
3426 { | 3819 { |
3427 /* Background is already in screen gamma */ | 3820 /* Background is already in screen gamma */ |
3428 *dp = (png_byte)((background->red >> 8) & 0xff); | 3821 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
3429 *(dp + 1) = (png_byte)(background->red & 0xff); | 3822 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
3430 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); | 3823 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) |
3431 *(dp + 3) = (png_byte)(background->green & 0xff); | 3824 & 0xff); |
3432 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); | 3825 *(sp + 3) = (png_byte)(png_ptr->background.green |
3433 *(dp + 5) = (png_byte)(background->blue & 0xff); | 3826 & 0xff); |
| 3827 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) |
| 3828 & 0xff); |
| 3829 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
3434 } | 3830 } |
| 3831 |
3435 else | 3832 else |
3436 { | 3833 { |
3437 png_uint_16 v, w, x; | 3834 png_uint_16 v, w; |
3438 | 3835 |
3439 v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; | 3836 v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
3440 png_composite_16(w, v, a, background_1->red); | 3837 png_composite_16(w, v, a, png_ptr->background_1.red); |
3441 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; | 3838 if (optimize == 0) |
3442 *dp = (png_byte)((x >> 8) & 0xff); | 3839 w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> |
3443 *(dp + 1) = (png_byte)(x & 0xff); | 3840 8]; |
| 3841 *sp = (png_byte)((w >> 8) & 0xff); |
| 3842 *(sp + 1) = (png_byte)(w & 0xff); |
| 3843 |
3444 v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; | 3844 v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
3445 png_composite_16(w, v, a, background_1->green); | 3845 png_composite_16(w, v, a, png_ptr->background_1.green); |
3446 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; | 3846 if (optimize == 0) |
3447 *(dp + 2) = (png_byte)((x >> 8) & 0xff); | 3847 w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> |
3448 *(dp + 3) = (png_byte)(x & 0xff); | 3848 8]; |
| 3849 |
| 3850 *(sp + 2) = (png_byte)((w >> 8) & 0xff); |
| 3851 *(sp + 3) = (png_byte)(w & 0xff); |
| 3852 |
3449 v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; | 3853 v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
3450 png_composite_16(w, v, a, background_1->blue); | 3854 png_composite_16(w, v, a, png_ptr->background_1.blue); |
3451 x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; | 3855 if (optimize == 0) |
3452 *(dp + 4) = (png_byte)((x >> 8) & 0xff); | 3856 w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >> |
3453 *(dp + 5) = (png_byte)(x & 0xff); | 3857 8]; |
| 3858 |
| 3859 *(sp + 4) = (png_byte)((w >> 8) & 0xff); |
| 3860 *(sp + 5) = (png_byte)(w & 0xff); |
3454 } | 3861 } |
3455 } | 3862 } |
3456 } | 3863 } |
| 3864 |
3457 else | 3865 else |
3458 #endif | 3866 #endif |
3459 { | 3867 { |
3460 sp = row; | 3868 sp = row; |
3461 dp = row; | 3869 for (i = 0; i < row_width; i++, sp += 8) |
3462 for (i = 0; i < row_width; i++, sp += 8, dp += 6) | |
3463 { | 3870 { |
3464 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) | 3871 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
3465 << 8) + (png_uint_16)(*(sp + 7))); | 3872 << 8) + (png_uint_16)(*(sp + 7))); |
3466 if (a == (png_uint_16)0xffff) | 3873 |
| 3874 if (a == 0) |
3467 { | 3875 { |
3468 png_memcpy(dp, sp, 6); | 3876 *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff); |
| 3877 *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff); |
| 3878 *(sp + 2) = (png_byte)((png_ptr->background.green >> 8) |
| 3879 & 0xff); |
| 3880 *(sp + 3) = (png_byte)(png_ptr->background.green |
| 3881 & 0xff); |
| 3882 *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8) |
| 3883 & 0xff); |
| 3884 *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff); |
3469 } | 3885 } |
3470 else if (a == 0) | 3886 |
3471 { | 3887 else if (a < 0xffff) |
3472 *dp = (png_byte)((background->red >> 8) & 0xff); | |
3473 *(dp + 1) = (png_byte)(background->red & 0xff); | |
3474 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); | |
3475 *(dp + 3) = (png_byte)(background->green & 0xff); | |
3476 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); | |
3477 *(dp + 5) = (png_byte)(background->blue & 0xff); | |
3478 } | |
3479 else | |
3480 { | 3888 { |
3481 png_uint_16 v; | 3889 png_uint_16 v; |
3482 | 3890 |
3483 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); | 3891 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
3484 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) | 3892 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
3485 + *(sp + 3)); | 3893 + *(sp + 3)); |
3486 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) | 3894 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
3487 + *(sp + 5)); | 3895 + *(sp + 5)); |
3488 | 3896 |
3489 png_composite_16(v, r, a, background->red); | 3897 png_composite_16(v, r, a, png_ptr->background.red); |
3490 *dp = (png_byte)((v >> 8) & 0xff); | 3898 *sp = (png_byte)((v >> 8) & 0xff); |
3491 *(dp + 1) = (png_byte)(v & 0xff); | 3899 *(sp + 1) = (png_byte)(v & 0xff); |
3492 png_composite_16(v, g, a, background->green); | 3900 |
3493 *(dp + 2) = (png_byte)((v >> 8) & 0xff); | 3901 png_composite_16(v, g, a, png_ptr->background.green); |
3494 *(dp + 3) = (png_byte)(v & 0xff); | 3902 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
3495 png_composite_16(v, b, a, background->blue); | 3903 *(sp + 3) = (png_byte)(v & 0xff); |
3496 *(dp + 4) = (png_byte)((v >> 8) & 0xff); | 3904 |
3497 *(dp + 5) = (png_byte)(v & 0xff); | 3905 png_composite_16(v, b, a, png_ptr->background.blue); |
| 3906 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
| 3907 *(sp + 5) = (png_byte)(v & 0xff); |
3498 } | 3908 } |
3499 } | 3909 } |
3500 } | 3910 } |
3501 } | 3911 } |
3502 break; | 3912 break; |
3503 } | 3913 } |
3504 } | |
3505 | 3914 |
3506 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) | 3915 default: |
3507 { | 3916 break; |
3508 row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; | |
3509 row_info->channels--; | |
3510 row_info->pixel_depth = (png_byte)(row_info->channels * | |
3511 row_info->bit_depth); | |
3512 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | |
3513 } | 3917 } |
3514 } | 3918 } |
3515 } | 3919 } |
3516 #endif | 3920 #endif /* READ_BACKGROUND || READ_ALPHA_MODE */ |
3517 | 3921 |
3518 #ifdef PNG_READ_GAMMA_SUPPORTED | 3922 #ifdef PNG_READ_GAMMA_SUPPORTED |
3519 /* Gamma correct the image, avoiding the alpha channel. Make sure | 3923 /* Gamma correct the image, avoiding the alpha channel. Make sure |
3520 * you do this after you deal with the transparency issue on grayscale | 3924 * you do this after you deal with the transparency issue on grayscale |
3521 * or RGB images. If your bit depth is 8, use gamma_table, if it | 3925 * or RGB images. If your bit depth is 8, use gamma_table, if it |
3522 * is 16, use gamma_16_table and gamma_shift. Build these with | 3926 * is 16, use gamma_16_table and gamma_shift. Build these with |
3523 * build_gamma_table(). | 3927 * build_gamma_table(). |
3524 */ | 3928 */ |
3525 void /* PRIVATE */ | 3929 static void |
3526 png_do_gamma(png_row_infop row_info, png_bytep row, | 3930 png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr) |
3527 png_bytep gamma_table, png_uint_16pp gamma_16_table, | |
3528 int gamma_shift) | |
3529 { | 3931 { |
| 3932 png_const_bytep gamma_table = png_ptr->gamma_table; |
| 3933 png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table; |
| 3934 int gamma_shift = png_ptr->gamma_shift; |
| 3935 |
3530 png_bytep sp; | 3936 png_bytep sp; |
3531 png_uint_32 i; | 3937 png_uint_32 i; |
3532 png_uint_32 row_width=row_info->width; | 3938 png_uint_32 row_width=row_info->width; |
3533 | 3939 |
3534 png_debug(1, "in png_do_gamma"); | 3940 png_debug(1, "in png_do_gamma"); |
3535 | 3941 |
3536 if ( | 3942 if (((row_info->bit_depth <= 8 && gamma_table != NULL) || |
3537 #ifdef PNG_USELESS_TESTS_SUPPORTED | 3943 (row_info->bit_depth == 16 && gamma_16_table != NULL))) |
3538 row != NULL && row_info != NULL && | |
3539 #endif | |
3540 ((row_info->bit_depth <= 8 && gamma_table != NULL) || | |
3541 (row_info->bit_depth == 16 && gamma_16_table != NULL))) | |
3542 { | 3944 { |
3543 switch (row_info->color_type) | 3945 switch (row_info->color_type) |
3544 { | 3946 { |
3545 case PNG_COLOR_TYPE_RGB: | 3947 case PNG_COLOR_TYPE_RGB: |
3546 { | 3948 { |
3547 if (row_info->bit_depth == 8) | 3949 if (row_info->bit_depth == 8) |
3548 { | 3950 { |
3549 sp = row; | 3951 sp = row; |
3550 for (i = 0; i < row_width; i++) | 3952 for (i = 0; i < row_width; i++) |
3551 { | 3953 { |
3552 *sp = gamma_table[*sp]; | 3954 *sp = gamma_table[*sp]; |
3553 sp++; | 3955 sp++; |
3554 *sp = gamma_table[*sp]; | 3956 *sp = gamma_table[*sp]; |
3555 sp++; | 3957 sp++; |
3556 *sp = gamma_table[*sp]; | 3958 *sp = gamma_table[*sp]; |
3557 sp++; | 3959 sp++; |
3558 } | 3960 } |
3559 } | 3961 } |
| 3962 |
3560 else /* if (row_info->bit_depth == 16) */ | 3963 else /* if (row_info->bit_depth == 16) */ |
3561 { | 3964 { |
3562 sp = row; | 3965 sp = row; |
3563 for (i = 0; i < row_width; i++) | 3966 for (i = 0; i < row_width; i++) |
3564 { | 3967 { |
3565 png_uint_16 v; | 3968 png_uint_16 v; |
3566 | 3969 |
3567 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 3970 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3568 *sp = (png_byte)((v >> 8) & 0xff); | 3971 *sp = (png_byte)((v >> 8) & 0xff); |
3569 *(sp + 1) = (png_byte)(v & 0xff); | 3972 *(sp + 1) = (png_byte)(v & 0xff); |
3570 sp += 2; | 3973 sp += 2; |
| 3974 |
3571 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 3975 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3572 *sp = (png_byte)((v >> 8) & 0xff); | 3976 *sp = (png_byte)((v >> 8) & 0xff); |
3573 *(sp + 1) = (png_byte)(v & 0xff); | 3977 *(sp + 1) = (png_byte)(v & 0xff); |
3574 sp += 2; | 3978 sp += 2; |
| 3979 |
3575 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 3980 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3576 *sp = (png_byte)((v >> 8) & 0xff); | 3981 *sp = (png_byte)((v >> 8) & 0xff); |
3577 *(sp + 1) = (png_byte)(v & 0xff); | 3982 *(sp + 1) = (png_byte)(v & 0xff); |
3578 sp += 2; | 3983 sp += 2; |
3579 } | 3984 } |
3580 } | 3985 } |
3581 break; | 3986 break; |
3582 } | 3987 } |
3583 | 3988 |
3584 case PNG_COLOR_TYPE_RGB_ALPHA: | 3989 case PNG_COLOR_TYPE_RGB_ALPHA: |
3585 { | 3990 { |
3586 if (row_info->bit_depth == 8) | 3991 if (row_info->bit_depth == 8) |
3587 { | 3992 { |
3588 sp = row; | 3993 sp = row; |
3589 for (i = 0; i < row_width; i++) | 3994 for (i = 0; i < row_width; i++) |
3590 { | 3995 { |
3591 *sp = gamma_table[*sp]; | 3996 *sp = gamma_table[*sp]; |
3592 sp++; | 3997 sp++; |
| 3998 |
3593 *sp = gamma_table[*sp]; | 3999 *sp = gamma_table[*sp]; |
3594 sp++; | 4000 sp++; |
| 4001 |
3595 *sp = gamma_table[*sp]; | 4002 *sp = gamma_table[*sp]; |
3596 sp++; | 4003 sp++; |
| 4004 |
3597 sp++; | 4005 sp++; |
3598 } | 4006 } |
3599 } | 4007 } |
| 4008 |
3600 else /* if (row_info->bit_depth == 16) */ | 4009 else /* if (row_info->bit_depth == 16) */ |
3601 { | 4010 { |
3602 sp = row; | 4011 sp = row; |
3603 for (i = 0; i < row_width; i++) | 4012 for (i = 0; i < row_width; i++) |
3604 { | 4013 { |
3605 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 4014 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3606 *sp = (png_byte)((v >> 8) & 0xff); | 4015 *sp = (png_byte)((v >> 8) & 0xff); |
3607 *(sp + 1) = (png_byte)(v & 0xff); | 4016 *(sp + 1) = (png_byte)(v & 0xff); |
3608 sp += 2; | 4017 sp += 2; |
| 4018 |
3609 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 4019 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3610 *sp = (png_byte)((v >> 8) & 0xff); | 4020 *sp = (png_byte)((v >> 8) & 0xff); |
3611 *(sp + 1) = (png_byte)(v & 0xff); | 4021 *(sp + 1) = (png_byte)(v & 0xff); |
3612 sp += 2; | 4022 sp += 2; |
| 4023 |
3613 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 4024 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3614 *sp = (png_byte)((v >> 8) & 0xff); | 4025 *sp = (png_byte)((v >> 8) & 0xff); |
3615 *(sp + 1) = (png_byte)(v & 0xff); | 4026 *(sp + 1) = (png_byte)(v & 0xff); |
3616 sp += 4; | 4027 sp += 4; |
3617 } | 4028 } |
3618 } | 4029 } |
3619 break; | 4030 break; |
3620 } | 4031 } |
3621 | 4032 |
3622 case PNG_COLOR_TYPE_GRAY_ALPHA: | 4033 case PNG_COLOR_TYPE_GRAY_ALPHA: |
3623 { | 4034 { |
3624 if (row_info->bit_depth == 8) | 4035 if (row_info->bit_depth == 8) |
3625 { | 4036 { |
3626 sp = row; | 4037 sp = row; |
3627 for (i = 0; i < row_width; i++) | 4038 for (i = 0; i < row_width; i++) |
3628 { | 4039 { |
3629 *sp = gamma_table[*sp]; | 4040 *sp = gamma_table[*sp]; |
3630 sp += 2; | 4041 sp += 2; |
3631 } | 4042 } |
3632 } | 4043 } |
| 4044 |
3633 else /* if (row_info->bit_depth == 16) */ | 4045 else /* if (row_info->bit_depth == 16) */ |
3634 { | 4046 { |
3635 sp = row; | 4047 sp = row; |
3636 for (i = 0; i < row_width; i++) | 4048 for (i = 0; i < row_width; i++) |
3637 { | 4049 { |
3638 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 4050 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3639 *sp = (png_byte)((v >> 8) & 0xff); | 4051 *sp = (png_byte)((v >> 8) & 0xff); |
3640 *(sp + 1) = (png_byte)(v & 0xff); | 4052 *(sp + 1) = (png_byte)(v & 0xff); |
3641 sp += 4; | 4053 sp += 4; |
3642 } | 4054 } |
(...skipping 52 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
3695 for (i = 0; i < row_width; i++) | 4107 for (i = 0; i < row_width; i++) |
3696 { | 4108 { |
3697 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; | 4109 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
3698 *sp = (png_byte)((v >> 8) & 0xff); | 4110 *sp = (png_byte)((v >> 8) & 0xff); |
3699 *(sp + 1) = (png_byte)(v & 0xff); | 4111 *(sp + 1) = (png_byte)(v & 0xff); |
3700 sp += 2; | 4112 sp += 2; |
3701 } | 4113 } |
3702 } | 4114 } |
3703 break; | 4115 break; |
3704 } | 4116 } |
| 4117 |
| 4118 default: |
| 4119 break; |
3705 } | 4120 } |
3706 } | 4121 } |
3707 } | 4122 } |
3708 #endif | 4123 #endif |
3709 | 4124 |
| 4125 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
| 4126 /* Encode the alpha channel to the output gamma (the input channel is always |
| 4127 * linear.) Called only with color types that have an alpha channel. Needs the |
| 4128 * from_1 tables. |
| 4129 */ |
| 4130 static void |
| 4131 png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr) |
| 4132 { |
| 4133 png_uint_32 row_width = row_info->width; |
| 4134 |
| 4135 png_debug(1, "in png_do_encode_alpha"); |
| 4136 |
| 4137 if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) |
| 4138 { |
| 4139 if (row_info->bit_depth == 8) |
| 4140 { |
| 4141 PNG_CONST png_bytep table = png_ptr->gamma_from_1; |
| 4142 |
| 4143 if (table != NULL) |
| 4144 { |
| 4145 PNG_CONST int step = |
| 4146 (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2; |
| 4147 |
| 4148 /* The alpha channel is the last component: */ |
| 4149 row += step - 1; |
| 4150 |
| 4151 for (; row_width > 0; --row_width, row += step) |
| 4152 *row = table[*row]; |
| 4153 |
| 4154 return; |
| 4155 } |
| 4156 } |
| 4157 |
| 4158 else if (row_info->bit_depth == 16) |
| 4159 { |
| 4160 PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1; |
| 4161 PNG_CONST int gamma_shift = png_ptr->gamma_shift; |
| 4162 |
| 4163 if (table != NULL) |
| 4164 { |
| 4165 PNG_CONST int step = |
| 4166 (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4; |
| 4167 |
| 4168 /* The alpha channel is the last component: */ |
| 4169 row += step - 2; |
| 4170 |
| 4171 for (; row_width > 0; --row_width, row += step) |
| 4172 { |
| 4173 png_uint_16 v; |
| 4174 |
| 4175 v = table[*(row + 1) >> gamma_shift][*row]; |
| 4176 *row = (png_byte)((v >> 8) & 0xff); |
| 4177 *(row + 1) = (png_byte)(v & 0xff); |
| 4178 } |
| 4179 |
| 4180 return; |
| 4181 } |
| 4182 } |
| 4183 } |
| 4184 |
| 4185 /* Only get to here if called with a weird row_info; no harm has been done, |
| 4186 * so just issue a warning. |
| 4187 */ |
| 4188 png_warning(png_ptr, "png_do_encode_alpha: unexpected call"); |
| 4189 } |
| 4190 #endif |
| 4191 |
3710 #ifdef PNG_READ_EXPAND_SUPPORTED | 4192 #ifdef PNG_READ_EXPAND_SUPPORTED |
3711 /* Expands a palette row to an RGB or RGBA row depending | 4193 /* Expands a palette row to an RGB or RGBA row depending |
3712 * upon whether you supply trans and num_trans. | 4194 * upon whether you supply trans and num_trans. |
3713 */ | 4195 */ |
3714 void /* PRIVATE */ | 4196 static void |
3715 png_do_expand_palette(png_row_infop row_info, png_bytep row, | 4197 png_do_expand_palette(png_row_infop row_info, png_bytep row, |
3716 png_colorp palette, png_bytep trans, int num_trans) | 4198 png_const_colorp palette, png_const_bytep trans_alpha, int num_trans) |
3717 { | 4199 { |
3718 int shift, value; | 4200 int shift, value; |
3719 png_bytep sp, dp; | 4201 png_bytep sp, dp; |
3720 png_uint_32 i; | 4202 png_uint_32 i; |
3721 png_uint_32 row_width=row_info->width; | 4203 png_uint_32 row_width=row_info->width; |
3722 | 4204 |
3723 png_debug(1, "in png_do_expand_palette"); | 4205 png_debug(1, "in png_do_expand_palette"); |
3724 | 4206 |
3725 if ( | 4207 if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) |
3726 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
3727 row != NULL && row_info != NULL && | |
3728 #endif | |
3729 row_info->color_type == PNG_COLOR_TYPE_PALETTE) | |
3730 { | 4208 { |
3731 if (row_info->bit_depth < 8) | 4209 if (row_info->bit_depth < 8) |
3732 { | 4210 { |
3733 switch (row_info->bit_depth) | 4211 switch (row_info->bit_depth) |
3734 { | 4212 { |
3735 case 1: | 4213 case 1: |
3736 { | 4214 { |
3737 sp = row + (png_size_t)((row_width - 1) >> 3); | 4215 sp = row + (png_size_t)((row_width - 1) >> 3); |
3738 dp = row + (png_size_t)row_width - 1; | 4216 dp = row + (png_size_t)row_width - 1; |
3739 shift = 7 - (int)((row_width + 7) & 0x07); | 4217 shift = 7 - (int)((row_width + 7) & 0x07); |
3740 for (i = 0; i < row_width; i++) | 4218 for (i = 0; i < row_width; i++) |
3741 { | 4219 { |
3742 if ((*sp >> shift) & 0x01) | 4220 if ((*sp >> shift) & 0x01) |
3743 *dp = 1; | 4221 *dp = 1; |
| 4222 |
3744 else | 4223 else |
3745 *dp = 0; | 4224 *dp = 0; |
| 4225 |
3746 if (shift == 7) | 4226 if (shift == 7) |
3747 { | 4227 { |
3748 shift = 0; | 4228 shift = 0; |
3749 sp--; | 4229 sp--; |
3750 } | 4230 } |
| 4231 |
3751 else | 4232 else |
3752 shift++; | 4233 shift++; |
3753 | 4234 |
3754 dp--; | 4235 dp--; |
3755 } | 4236 } |
3756 break; | 4237 break; |
3757 } | 4238 } |
3758 | 4239 |
3759 case 2: | 4240 case 2: |
3760 { | 4241 { |
3761 sp = row + (png_size_t)((row_width - 1) >> 2); | 4242 sp = row + (png_size_t)((row_width - 1) >> 2); |
3762 dp = row + (png_size_t)row_width - 1; | 4243 dp = row + (png_size_t)row_width - 1; |
3763 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); | 4244 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
3764 for (i = 0; i < row_width; i++) | 4245 for (i = 0; i < row_width; i++) |
3765 { | 4246 { |
3766 value = (*sp >> shift) & 0x03; | 4247 value = (*sp >> shift) & 0x03; |
3767 *dp = (png_byte)value; | 4248 *dp = (png_byte)value; |
3768 if (shift == 6) | 4249 if (shift == 6) |
3769 { | 4250 { |
3770 shift = 0; | 4251 shift = 0; |
3771 sp--; | 4252 sp--; |
3772 } | 4253 } |
| 4254 |
3773 else | 4255 else |
3774 shift += 2; | 4256 shift += 2; |
3775 | 4257 |
3776 dp--; | 4258 dp--; |
3777 } | 4259 } |
3778 break; | 4260 break; |
3779 } | 4261 } |
3780 | 4262 |
3781 case 4: | 4263 case 4: |
3782 { | 4264 { |
3783 sp = row + (png_size_t)((row_width - 1) >> 1); | 4265 sp = row + (png_size_t)((row_width - 1) >> 1); |
3784 dp = row + (png_size_t)row_width - 1; | 4266 dp = row + (png_size_t)row_width - 1; |
3785 shift = (int)((row_width & 0x01) << 2); | 4267 shift = (int)((row_width & 0x01) << 2); |
3786 for (i = 0; i < row_width; i++) | 4268 for (i = 0; i < row_width; i++) |
3787 { | 4269 { |
3788 value = (*sp >> shift) & 0x0f; | 4270 value = (*sp >> shift) & 0x0f; |
3789 *dp = (png_byte)value; | 4271 *dp = (png_byte)value; |
3790 if (shift == 4) | 4272 if (shift == 4) |
3791 { | 4273 { |
3792 shift = 0; | 4274 shift = 0; |
3793 sp--; | 4275 sp--; |
3794 } | 4276 } |
| 4277 |
3795 else | 4278 else |
3796 shift += 4; | 4279 shift += 4; |
3797 | 4280 |
3798 dp--; | 4281 dp--; |
3799 } | 4282 } |
3800 break; | 4283 break; |
3801 } | 4284 } |
| 4285 |
| 4286 default: |
| 4287 break; |
3802 } | 4288 } |
3803 row_info->bit_depth = 8; | 4289 row_info->bit_depth = 8; |
3804 row_info->pixel_depth = 8; | 4290 row_info->pixel_depth = 8; |
3805 row_info->rowbytes = row_width; | 4291 row_info->rowbytes = row_width; |
3806 } | 4292 } |
3807 switch (row_info->bit_depth) | 4293 |
| 4294 if (row_info->bit_depth == 8) |
3808 { | 4295 { |
3809 case 8: | |
3810 { | 4296 { |
3811 if (trans != NULL) | 4297 if (num_trans > 0) |
3812 { | 4298 { |
3813 sp = row + (png_size_t)row_width - 1; | 4299 sp = row + (png_size_t)row_width - 1; |
3814 dp = row + (png_size_t)(row_width << 2) - 1; | 4300 dp = row + (png_size_t)(row_width << 2) - 1; |
3815 | 4301 |
3816 for (i = 0; i < row_width; i++) | 4302 for (i = 0; i < row_width; i++) |
3817 { | 4303 { |
3818 if ((int)(*sp) >= num_trans) | 4304 if ((int)(*sp) >= num_trans) |
3819 *dp-- = 0xff; | 4305 *dp-- = 0xff; |
| 4306 |
3820 else | 4307 else |
3821 *dp-- = trans[*sp]; | 4308 *dp-- = trans_alpha[*sp]; |
| 4309 |
3822 *dp-- = palette[*sp].blue; | 4310 *dp-- = palette[*sp].blue; |
3823 *dp-- = palette[*sp].green; | 4311 *dp-- = palette[*sp].green; |
3824 *dp-- = palette[*sp].red; | 4312 *dp-- = palette[*sp].red; |
3825 sp--; | 4313 sp--; |
3826 } | 4314 } |
3827 row_info->bit_depth = 8; | 4315 row_info->bit_depth = 8; |
3828 row_info->pixel_depth = 32; | 4316 row_info->pixel_depth = 32; |
3829 row_info->rowbytes = row_width * 4; | 4317 row_info->rowbytes = row_width * 4; |
3830 row_info->color_type = 6; | 4318 row_info->color_type = 6; |
3831 row_info->channels = 4; | 4319 row_info->channels = 4; |
3832 } | 4320 } |
| 4321 |
3833 else | 4322 else |
3834 { | 4323 { |
3835 sp = row + (png_size_t)row_width - 1; | 4324 sp = row + (png_size_t)row_width - 1; |
3836 dp = row + (png_size_t)(row_width * 3) - 1; | 4325 dp = row + (png_size_t)(row_width * 3) - 1; |
3837 | 4326 |
3838 for (i = 0; i < row_width; i++) | 4327 for (i = 0; i < row_width; i++) |
3839 { | 4328 { |
3840 *dp-- = palette[*sp].blue; | 4329 *dp-- = palette[*sp].blue; |
3841 *dp-- = palette[*sp].green; | 4330 *dp-- = palette[*sp].green; |
3842 *dp-- = palette[*sp].red; | 4331 *dp-- = palette[*sp].red; |
3843 sp--; | 4332 sp--; |
3844 } | 4333 } |
3845 | 4334 |
3846 row_info->bit_depth = 8; | 4335 row_info->bit_depth = 8; |
3847 row_info->pixel_depth = 24; | 4336 row_info->pixel_depth = 24; |
3848 row_info->rowbytes = row_width * 3; | 4337 row_info->rowbytes = row_width * 3; |
3849 row_info->color_type = 2; | 4338 row_info->color_type = 2; |
3850 row_info->channels = 3; | 4339 row_info->channels = 3; |
3851 } | 4340 } |
3852 break; | |
3853 } | 4341 } |
3854 } | 4342 } |
3855 } | 4343 } |
3856 } | 4344 } |
3857 | 4345 |
3858 /* If the bit depth < 8, it is expanded to 8. Also, if the already | 4346 /* If the bit depth < 8, it is expanded to 8. Also, if the already |
3859 * expanded transparency value is supplied, an alpha channel is built. | 4347 * expanded transparency value is supplied, an alpha channel is built. |
3860 */ | 4348 */ |
3861 void /* PRIVATE */ | 4349 static void |
3862 png_do_expand(png_row_infop row_info, png_bytep row, | 4350 png_do_expand(png_row_infop row_info, png_bytep row, |
3863 png_color_16p trans_value) | 4351 png_const_color_16p trans_color) |
3864 { | 4352 { |
3865 int shift, value; | 4353 int shift, value; |
3866 png_bytep sp, dp; | 4354 png_bytep sp, dp; |
3867 png_uint_32 i; | 4355 png_uint_32 i; |
3868 png_uint_32 row_width=row_info->width; | 4356 png_uint_32 row_width=row_info->width; |
3869 | 4357 |
3870 png_debug(1, "in png_do_expand"); | 4358 png_debug(1, "in png_do_expand"); |
3871 | 4359 |
3872 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
3873 if (row != NULL && row_info != NULL) | |
3874 #endif | |
3875 { | 4360 { |
3876 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) | 4361 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
3877 { | 4362 { |
3878 png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0); | 4363 unsigned int gray = trans_color != NULL ? trans_color->gray : 0; |
3879 | 4364 |
3880 if (row_info->bit_depth < 8) | 4365 if (row_info->bit_depth < 8) |
3881 { | 4366 { |
3882 switch (row_info->bit_depth) | 4367 switch (row_info->bit_depth) |
3883 { | 4368 { |
3884 case 1: | 4369 case 1: |
3885 { | 4370 { |
3886 gray = (png_uint_16)((gray&0x01)*0xff); | 4371 gray = (gray & 0x01) * 0xff; |
3887 sp = row + (png_size_t)((row_width - 1) >> 3); | 4372 sp = row + (png_size_t)((row_width - 1) >> 3); |
3888 dp = row + (png_size_t)row_width - 1; | 4373 dp = row + (png_size_t)row_width - 1; |
3889 shift = 7 - (int)((row_width + 7) & 0x07); | 4374 shift = 7 - (int)((row_width + 7) & 0x07); |
3890 for (i = 0; i < row_width; i++) | 4375 for (i = 0; i < row_width; i++) |
3891 { | 4376 { |
3892 if ((*sp >> shift) & 0x01) | 4377 if ((*sp >> shift) & 0x01) |
3893 *dp = 0xff; | 4378 *dp = 0xff; |
| 4379 |
3894 else | 4380 else |
3895 *dp = 0; | 4381 *dp = 0; |
| 4382 |
3896 if (shift == 7) | 4383 if (shift == 7) |
3897 { | 4384 { |
3898 shift = 0; | 4385 shift = 0; |
3899 sp--; | 4386 sp--; |
3900 } | 4387 } |
| 4388 |
3901 else | 4389 else |
3902 shift++; | 4390 shift++; |
3903 | 4391 |
3904 dp--; | 4392 dp--; |
3905 } | 4393 } |
3906 break; | 4394 break; |
3907 } | 4395 } |
3908 | 4396 |
3909 case 2: | 4397 case 2: |
3910 { | 4398 { |
3911 gray = (png_uint_16)((gray&0x03)*0x55); | 4399 gray = (gray & 0x03) * 0x55; |
3912 sp = row + (png_size_t)((row_width - 1) >> 2); | 4400 sp = row + (png_size_t)((row_width - 1) >> 2); |
3913 dp = row + (png_size_t)row_width - 1; | 4401 dp = row + (png_size_t)row_width - 1; |
3914 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); | 4402 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
3915 for (i = 0; i < row_width; i++) | 4403 for (i = 0; i < row_width; i++) |
3916 { | 4404 { |
3917 value = (*sp >> shift) & 0x03; | 4405 value = (*sp >> shift) & 0x03; |
3918 *dp = (png_byte)(value | (value << 2) | (value << 4) | | 4406 *dp = (png_byte)(value | (value << 2) | (value << 4) | |
3919 (value << 6)); | 4407 (value << 6)); |
3920 if (shift == 6) | 4408 if (shift == 6) |
3921 { | 4409 { |
3922 shift = 0; | 4410 shift = 0; |
3923 sp--; | 4411 sp--; |
3924 } | 4412 } |
| 4413 |
3925 else | 4414 else |
3926 shift += 2; | 4415 shift += 2; |
3927 | 4416 |
3928 dp--; | 4417 dp--; |
3929 } | 4418 } |
3930 break; | 4419 break; |
3931 } | 4420 } |
3932 | 4421 |
3933 case 4: | 4422 case 4: |
3934 { | 4423 { |
3935 gray = (png_uint_16)((gray&0x0f)*0x11); | 4424 gray = (gray & 0x0f) * 0x11; |
3936 sp = row + (png_size_t)((row_width - 1) >> 1); | 4425 sp = row + (png_size_t)((row_width - 1) >> 1); |
3937 dp = row + (png_size_t)row_width - 1; | 4426 dp = row + (png_size_t)row_width - 1; |
3938 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); | 4427 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
3939 for (i = 0; i < row_width; i++) | 4428 for (i = 0; i < row_width; i++) |
3940 { | 4429 { |
3941 value = (*sp >> shift) & 0x0f; | 4430 value = (*sp >> shift) & 0x0f; |
3942 *dp = (png_byte)(value | (value << 4)); | 4431 *dp = (png_byte)(value | (value << 4)); |
3943 if (shift == 4) | 4432 if (shift == 4) |
3944 { | 4433 { |
3945 shift = 0; | 4434 shift = 0; |
3946 sp--; | 4435 sp--; |
3947 } | 4436 } |
| 4437 |
3948 else | 4438 else |
3949 shift = 4; | 4439 shift = 4; |
3950 | 4440 |
3951 dp--; | 4441 dp--; |
3952 } | 4442 } |
3953 break; | 4443 break; |
3954 } | 4444 } |
| 4445 |
| 4446 default: |
| 4447 break; |
3955 } | 4448 } |
3956 | 4449 |
3957 row_info->bit_depth = 8; | 4450 row_info->bit_depth = 8; |
3958 row_info->pixel_depth = 8; | 4451 row_info->pixel_depth = 8; |
3959 row_info->rowbytes = row_width; | 4452 row_info->rowbytes = row_width; |
3960 } | 4453 } |
3961 | 4454 |
3962 if (trans_value != NULL) | 4455 if (trans_color != NULL) |
3963 { | 4456 { |
3964 if (row_info->bit_depth == 8) | 4457 if (row_info->bit_depth == 8) |
3965 { | 4458 { |
3966 gray = gray & 0xff; | 4459 gray = gray & 0xff; |
3967 sp = row + (png_size_t)row_width - 1; | 4460 sp = row + (png_size_t)row_width - 1; |
3968 dp = row + (png_size_t)(row_width << 1) - 1; | 4461 dp = row + (png_size_t)(row_width << 1) - 1; |
| 4462 |
3969 for (i = 0; i < row_width; i++) | 4463 for (i = 0; i < row_width; i++) |
3970 { | 4464 { |
3971 if (*sp == gray) | 4465 if ((*sp & 0xffU) == gray) |
3972 *dp-- = 0; | 4466 *dp-- = 0; |
| 4467 |
3973 else | 4468 else |
3974 *dp-- = 0xff; | 4469 *dp-- = 0xff; |
| 4470 |
3975 *dp-- = *sp--; | 4471 *dp-- = *sp--; |
3976 } | 4472 } |
3977 } | 4473 } |
3978 | 4474 |
3979 else if (row_info->bit_depth == 16) | 4475 else if (row_info->bit_depth == 16) |
3980 { | 4476 { |
3981 png_byte gray_high = (gray >> 8) & 0xff; | 4477 unsigned int gray_high = (gray >> 8) & 0xff; |
3982 png_byte gray_low = gray & 0xff; | 4478 unsigned int gray_low = gray & 0xff; |
3983 sp = row + row_info->rowbytes - 1; | 4479 sp = row + row_info->rowbytes - 1; |
3984 dp = row + (row_info->rowbytes << 1) - 1; | 4480 dp = row + (row_info->rowbytes << 1) - 1; |
3985 for (i = 0; i < row_width; i++) | 4481 for (i = 0; i < row_width; i++) |
3986 { | 4482 { |
3987 if (*(sp - 1) == gray_high && *(sp) == gray_low) | 4483 if ((*(sp - 1) & 0xffU) == gray_high && |
| 4484 (*(sp) & 0xffU) == gray_low) |
3988 { | 4485 { |
3989 *dp-- = 0; | 4486 *dp-- = 0; |
3990 *dp-- = 0; | 4487 *dp-- = 0; |
3991 } | 4488 } |
| 4489 |
3992 else | 4490 else |
3993 { | 4491 { |
3994 *dp-- = 0xff; | 4492 *dp-- = 0xff; |
3995 *dp-- = 0xff; | 4493 *dp-- = 0xff; |
3996 } | 4494 } |
| 4495 |
3997 *dp-- = *sp--; | 4496 *dp-- = *sp--; |
3998 *dp-- = *sp--; | 4497 *dp-- = *sp--; |
3999 } | 4498 } |
4000 } | 4499 } |
4001 | 4500 |
4002 row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; | 4501 row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
4003 row_info->channels = 2; | 4502 row_info->channels = 2; |
4004 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); | 4503 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); |
4005 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, | 4504 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
4006 row_width); | 4505 row_width); |
4007 } | 4506 } |
4008 } | 4507 } |
4009 else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) | 4508 else if (row_info->color_type == PNG_COLOR_TYPE_RGB && |
| 4509 trans_color != NULL) |
4010 { | 4510 { |
4011 if (row_info->bit_depth == 8) | 4511 if (row_info->bit_depth == 8) |
4012 { | 4512 { |
4013 png_byte red = trans_value->red & 0xff; | 4513 png_byte red = (png_byte)(trans_color->red & 0xff); |
4014 png_byte green = trans_value->green & 0xff; | 4514 png_byte green = (png_byte)(trans_color->green & 0xff); |
4015 png_byte blue = trans_value->blue & 0xff; | 4515 png_byte blue = (png_byte)(trans_color->blue & 0xff); |
4016 sp = row + (png_size_t)row_info->rowbytes - 1; | 4516 sp = row + (png_size_t)row_info->rowbytes - 1; |
4017 dp = row + (png_size_t)(row_width << 2) - 1; | 4517 dp = row + (png_size_t)(row_width << 2) - 1; |
4018 for (i = 0; i < row_width; i++) | 4518 for (i = 0; i < row_width; i++) |
4019 { | 4519 { |
4020 if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) | 4520 if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) |
4021 *dp-- = 0; | 4521 *dp-- = 0; |
| 4522 |
4022 else | 4523 else |
4023 *dp-- = 0xff; | 4524 *dp-- = 0xff; |
| 4525 |
4024 *dp-- = *sp--; | 4526 *dp-- = *sp--; |
4025 *dp-- = *sp--; | 4527 *dp-- = *sp--; |
4026 *dp-- = *sp--; | 4528 *dp-- = *sp--; |
4027 } | 4529 } |
4028 } | 4530 } |
4029 else if (row_info->bit_depth == 16) | 4531 else if (row_info->bit_depth == 16) |
4030 { | 4532 { |
4031 png_byte red_high = (trans_value->red >> 8) & 0xff; | 4533 png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff); |
4032 png_byte green_high = (trans_value->green >> 8) & 0xff; | 4534 png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff); |
4033 png_byte blue_high = (trans_value->blue >> 8) & 0xff; | 4535 png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff); |
4034 png_byte red_low = trans_value->red & 0xff; | 4536 png_byte red_low = (png_byte)(trans_color->red & 0xff); |
4035 png_byte green_low = trans_value->green & 0xff; | 4537 png_byte green_low = (png_byte)(trans_color->green & 0xff); |
4036 png_byte blue_low = trans_value->blue & 0xff; | 4538 png_byte blue_low = (png_byte)(trans_color->blue & 0xff); |
4037 sp = row + row_info->rowbytes - 1; | 4539 sp = row + row_info->rowbytes - 1; |
4038 dp = row + (png_size_t)(row_width << 3) - 1; | 4540 dp = row + (png_size_t)(row_width << 3) - 1; |
4039 for (i = 0; i < row_width; i++) | 4541 for (i = 0; i < row_width; i++) |
4040 { | 4542 { |
4041 if (*(sp - 5) == red_high && | 4543 if (*(sp - 5) == red_high && |
4042 *(sp - 4) == red_low && | 4544 *(sp - 4) == red_low && |
4043 *(sp - 3) == green_high && | 4545 *(sp - 3) == green_high && |
4044 *(sp - 2) == green_low && | 4546 *(sp - 2) == green_low && |
4045 *(sp - 1) == blue_high && | 4547 *(sp - 1) == blue_high && |
4046 *(sp ) == blue_low) | 4548 *(sp ) == blue_low) |
4047 { | 4549 { |
4048 *dp-- = 0; | 4550 *dp-- = 0; |
4049 *dp-- = 0; | 4551 *dp-- = 0; |
4050 } | 4552 } |
| 4553 |
4051 else | 4554 else |
4052 { | 4555 { |
4053 *dp-- = 0xff; | 4556 *dp-- = 0xff; |
4054 *dp-- = 0xff; | 4557 *dp-- = 0xff; |
4055 } | 4558 } |
| 4559 |
4056 *dp-- = *sp--; | 4560 *dp-- = *sp--; |
4057 *dp-- = *sp--; | 4561 *dp-- = *sp--; |
4058 *dp-- = *sp--; | 4562 *dp-- = *sp--; |
4059 *dp-- = *sp--; | 4563 *dp-- = *sp--; |
4060 *dp-- = *sp--; | 4564 *dp-- = *sp--; |
4061 *dp-- = *sp--; | 4565 *dp-- = *sp--; |
4062 } | 4566 } |
4063 } | 4567 } |
4064 row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; | 4568 row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
4065 row_info->channels = 4; | 4569 row_info->channels = 4; |
4066 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); | 4570 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); |
4067 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | 4571 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
4068 } | 4572 } |
4069 } | 4573 } |
4070 } | 4574 } |
4071 #endif | 4575 #endif |
4072 | 4576 |
4073 #ifdef PNG_READ_DITHER_SUPPORTED | 4577 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
4074 void /* PRIVATE */ | 4578 /* If the bit depth is 8 and the color type is not a palette type expand the |
4075 png_do_dither(png_row_infop row_info, png_bytep row, | 4579 * whole row to 16 bits. Has no effect otherwise. |
4076 png_bytep palette_lookup, png_bytep dither_lookup) | 4580 */ |
| 4581 static void |
| 4582 png_do_expand_16(png_row_infop row_info, png_bytep row) |
| 4583 { |
| 4584 if (row_info->bit_depth == 8 && |
| 4585 row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
| 4586 { |
| 4587 /* The row have a sequence of bytes containing [0..255] and we need |
| 4588 * to turn it into another row containing [0..65535], to do this we |
| 4589 * calculate: |
| 4590 * |
| 4591 * (input / 255) * 65535 |
| 4592 * |
| 4593 * Which happens to be exactly input * 257 and this can be achieved |
| 4594 * simply by byte replication in place (copying backwards). |
| 4595 */ |
| 4596 png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */ |
| 4597 png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */ |
| 4598 while (dp > sp) |
| 4599 dp[-2] = dp[-1] = *--sp, dp -= 2; |
| 4600 |
| 4601 row_info->rowbytes *= 2; |
| 4602 row_info->bit_depth = 16; |
| 4603 row_info->pixel_depth = (png_byte)(row_info->channels * 16); |
| 4604 } |
| 4605 } |
| 4606 #endif |
| 4607 |
| 4608 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
| 4609 static void |
| 4610 png_do_quantize(png_row_infop row_info, png_bytep row, |
| 4611 png_const_bytep palette_lookup, png_const_bytep quantize_lookup) |
4077 { | 4612 { |
4078 png_bytep sp, dp; | 4613 png_bytep sp, dp; |
4079 png_uint_32 i; | 4614 png_uint_32 i; |
4080 png_uint_32 row_width=row_info->width; | 4615 png_uint_32 row_width=row_info->width; |
4081 | 4616 |
4082 png_debug(1, "in png_do_dither"); | 4617 png_debug(1, "in png_do_quantize"); |
4083 | 4618 |
4084 #ifdef PNG_USELESS_TESTS_SUPPORTED | 4619 if (row_info->bit_depth == 8) |
4085 if (row != NULL && row_info != NULL) | |
4086 #endif | |
4087 { | 4620 { |
4088 if (row_info->color_type == PNG_COLOR_TYPE_RGB && | 4621 if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup) |
4089 palette_lookup && row_info->bit_depth == 8) | |
4090 { | 4622 { |
4091 int r, g, b, p; | 4623 int r, g, b, p; |
4092 sp = row; | 4624 sp = row; |
4093 dp = row; | 4625 dp = row; |
4094 for (i = 0; i < row_width; i++) | 4626 for (i = 0; i < row_width; i++) |
4095 { | 4627 { |
4096 r = *sp++; | 4628 r = *sp++; |
4097 g = *sp++; | 4629 g = *sp++; |
4098 b = *sp++; | 4630 b = *sp++; |
4099 | 4631 |
4100 /* This looks real messy, but the compiler will reduce | 4632 /* This looks real messy, but the compiler will reduce |
4101 * it down to a reasonable formula. For example, with | 4633 * it down to a reasonable formula. For example, with |
4102 * 5 bits per color, we get: | 4634 * 5 bits per color, we get: |
4103 * p = (((r >> 3) & 0x1f) << 10) | | 4635 * p = (((r >> 3) & 0x1f) << 10) | |
4104 * (((g >> 3) & 0x1f) << 5) | | 4636 * (((g >> 3) & 0x1f) << 5) | |
4105 * ((b >> 3) & 0x1f); | 4637 * ((b >> 3) & 0x1f); |
4106 */ | 4638 */ |
4107 p = (((r >> (8 - PNG_DITHER_RED_BITS)) & | 4639 p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & |
4108 ((1 << PNG_DITHER_RED_BITS) - 1)) << | 4640 ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << |
4109 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | | 4641 (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | |
4110 (((g >> (8 - PNG_DITHER_GREEN_BITS)) & | 4642 (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & |
4111 ((1 << PNG_DITHER_GREEN_BITS) - 1)) << | 4643 ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << |
4112 (PNG_DITHER_BLUE_BITS)) | | 4644 (PNG_QUANTIZE_BLUE_BITS)) | |
4113 ((b >> (8 - PNG_DITHER_BLUE_BITS)) & | 4645 ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & |
4114 ((1 << PNG_DITHER_BLUE_BITS) - 1)); | 4646 ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); |
4115 | 4647 |
4116 *dp++ = palette_lookup[p]; | 4648 *dp++ = palette_lookup[p]; |
4117 } | 4649 } |
| 4650 |
4118 row_info->color_type = PNG_COLOR_TYPE_PALETTE; | 4651 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
4119 row_info->channels = 1; | 4652 row_info->channels = 1; |
4120 row_info->pixel_depth = row_info->bit_depth; | 4653 row_info->pixel_depth = row_info->bit_depth; |
4121 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | 4654 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
4122 } | 4655 } |
| 4656 |
4123 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && | 4657 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && |
4124 palette_lookup != NULL && row_info->bit_depth == 8) | 4658 palette_lookup != NULL) |
4125 { | 4659 { |
4126 int r, g, b, p; | 4660 int r, g, b, p; |
4127 sp = row; | 4661 sp = row; |
4128 dp = row; | 4662 dp = row; |
4129 for (i = 0; i < row_width; i++) | 4663 for (i = 0; i < row_width; i++) |
4130 { | 4664 { |
4131 r = *sp++; | 4665 r = *sp++; |
4132 g = *sp++; | 4666 g = *sp++; |
4133 b = *sp++; | 4667 b = *sp++; |
4134 sp++; | 4668 sp++; |
4135 | 4669 |
4136 p = (((r >> (8 - PNG_DITHER_RED_BITS)) & | 4670 p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) & |
4137 ((1 << PNG_DITHER_RED_BITS) - 1)) << | 4671 ((1 << PNG_QUANTIZE_RED_BITS) - 1)) << |
4138 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | | 4672 (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) | |
4139 (((g >> (8 - PNG_DITHER_GREEN_BITS)) & | 4673 (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) & |
4140 ((1 << PNG_DITHER_GREEN_BITS) - 1)) << | 4674 ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) << |
4141 (PNG_DITHER_BLUE_BITS)) | | 4675 (PNG_QUANTIZE_BLUE_BITS)) | |
4142 ((b >> (8 - PNG_DITHER_BLUE_BITS)) & | 4676 ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) & |
4143 ((1 << PNG_DITHER_BLUE_BITS) - 1)); | 4677 ((1 << PNG_QUANTIZE_BLUE_BITS) - 1)); |
4144 | 4678 |
4145 *dp++ = palette_lookup[p]; | 4679 *dp++ = palette_lookup[p]; |
4146 } | 4680 } |
| 4681 |
4147 row_info->color_type = PNG_COLOR_TYPE_PALETTE; | 4682 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
4148 row_info->channels = 1; | 4683 row_info->channels = 1; |
4149 row_info->pixel_depth = row_info->bit_depth; | 4684 row_info->pixel_depth = row_info->bit_depth; |
4150 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); | 4685 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
4151 } | 4686 } |
| 4687 |
4152 else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && | 4688 else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && |
4153 dither_lookup && row_info->bit_depth == 8) | 4689 quantize_lookup) |
4154 { | 4690 { |
4155 sp = row; | 4691 sp = row; |
| 4692 |
4156 for (i = 0; i < row_width; i++, sp++) | 4693 for (i = 0; i < row_width; i++, sp++) |
4157 { | 4694 { |
4158 *sp = dither_lookup[*sp]; | 4695 *sp = quantize_lookup[*sp]; |
4159 } | 4696 } |
4160 } | 4697 } |
4161 } | 4698 } |
4162 } | 4699 } |
4163 #endif | 4700 #endif /* READ_QUANTIZE */ |
4164 | 4701 |
4165 #ifdef PNG_FLOATING_POINT_SUPPORTED | 4702 /* Transform the row. The order of transformations is significant, |
| 4703 * and is very touchy. If you add a transformation, take care to |
| 4704 * decide how it fits in with the other transformations here. |
| 4705 */ |
| 4706 void /* PRIVATE */ |
| 4707 png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info) |
| 4708 { |
| 4709 png_debug(1, "in png_do_read_transformations"); |
| 4710 |
| 4711 if (png_ptr->row_buf == NULL) |
| 4712 { |
| 4713 /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this |
| 4714 * error is incredibly rare and incredibly easy to debug without this |
| 4715 * information. |
| 4716 */ |
| 4717 png_error(png_ptr, "NULL row buffer"); |
| 4718 } |
| 4719 |
| 4720 /* The following is debugging; prior to 1.5.4 the code was never compiled in; |
| 4721 * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro |
| 4722 * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for |
| 4723 * all transformations, however in practice the ROW_INIT always gets done on |
| 4724 * demand, if necessary. |
| 4725 */ |
| 4726 if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 && |
| 4727 (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0) |
| 4728 { |
| 4729 /* Application has failed to call either png_read_start_image() or |
| 4730 * png_read_update_info() after setting transforms that expand pixels. |
| 4731 * This check added to libpng-1.2.19 (but not enabled until 1.5.4). |
| 4732 */ |
| 4733 png_error(png_ptr, "Uninitialized row"); |
| 4734 } |
| 4735 |
| 4736 #ifdef PNG_READ_EXPAND_SUPPORTED |
| 4737 if ((png_ptr->transformations & PNG_EXPAND) != 0) |
| 4738 { |
| 4739 if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) |
| 4740 { |
| 4741 png_do_expand_palette(row_info, png_ptr->row_buf + 1, |
| 4742 png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); |
| 4743 } |
| 4744 |
| 4745 else |
| 4746 { |
| 4747 if (png_ptr->num_trans != 0 && |
| 4748 (png_ptr->transformations & PNG_EXPAND_tRNS) != 0) |
| 4749 png_do_expand(row_info, png_ptr->row_buf + 1, |
| 4750 &(png_ptr->trans_color)); |
| 4751 |
| 4752 else |
| 4753 png_do_expand(row_info, png_ptr->row_buf + 1, |
| 4754 NULL); |
| 4755 } |
| 4756 } |
| 4757 #endif |
| 4758 |
| 4759 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
| 4760 if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && |
| 4761 (png_ptr->transformations & PNG_COMPOSE) == 0 && |
| 4762 (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || |
| 4763 row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) |
| 4764 png_do_strip_channel(row_info, png_ptr->row_buf + 1, |
| 4765 0 /* at_start == false, because SWAP_ALPHA happens later */); |
| 4766 #endif |
| 4767 |
| 4768 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
| 4769 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0) |
| 4770 { |
| 4771 int rgb_error = |
| 4772 png_do_rgb_to_gray(png_ptr, row_info, |
| 4773 png_ptr->row_buf + 1); |
| 4774 |
| 4775 if (rgb_error != 0) |
| 4776 { |
| 4777 png_ptr->rgb_to_gray_status=1; |
| 4778 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
| 4779 PNG_RGB_TO_GRAY_WARN) |
| 4780 png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
| 4781 |
| 4782 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
| 4783 PNG_RGB_TO_GRAY_ERR) |
| 4784 png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
| 4785 } |
| 4786 } |
| 4787 #endif |
| 4788 |
| 4789 /* From Andreas Dilger e-mail to png-implement, 26 March 1998: |
| 4790 * |
| 4791 * In most cases, the "simple transparency" should be done prior to doing |
| 4792 * gray-to-RGB, or you will have to test 3x as many bytes to check if a |
| 4793 * pixel is transparent. You would also need to make sure that the |
| 4794 * transparency information is upgraded to RGB. |
| 4795 * |
| 4796 * To summarize, the current flow is: |
| 4797 * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite |
| 4798 * with background "in place" if transparent, |
| 4799 * convert to RGB if necessary |
| 4800 * - Gray + alpha -> composite with gray background and remove alpha bytes, |
| 4801 * convert to RGB if necessary |
| 4802 * |
| 4803 * To support RGB backgrounds for gray images we need: |
| 4804 * - Gray + simple transparency -> convert to RGB + simple transparency, |
| 4805 * compare 3 or 6 bytes and composite with |
| 4806 * background "in place" if transparent |
| 4807 * (3x compare/pixel compared to doing |
| 4808 * composite with gray bkgrnd) |
| 4809 * - Gray + alpha -> convert to RGB + alpha, composite with background and |
| 4810 * remove alpha bytes (3x float |
| 4811 * operations/pixel compared with composite |
| 4812 * on gray background) |
| 4813 * |
| 4814 * Greg's change will do this. The reason it wasn't done before is for |
| 4815 * performance, as this increases the per-pixel operations. If we would check |
| 4816 * in advance if the background was gray or RGB, and position the gray-to-RGB |
| 4817 * transform appropriately, then it would save a lot of work/time. |
| 4818 */ |
| 4819 |
| 4820 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
| 4821 /* If gray -> RGB, do so now only if background is non-gray; else do later |
| 4822 * for performance reasons |
| 4823 */ |
| 4824 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && |
| 4825 (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0) |
| 4826 png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); |
| 4827 #endif |
| 4828 |
| 4829 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ |
| 4830 defined(PNG_READ_ALPHA_MODE_SUPPORTED) |
| 4831 if ((png_ptr->transformations & PNG_COMPOSE) != 0) |
| 4832 png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr); |
| 4833 #endif |
| 4834 |
4166 #ifdef PNG_READ_GAMMA_SUPPORTED | 4835 #ifdef PNG_READ_GAMMA_SUPPORTED |
4167 static PNG_CONST int png_gamma_shift[] = | 4836 if ((png_ptr->transformations & PNG_GAMMA) != 0 && |
4168 {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00}; | 4837 #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
4169 | 4838 /* Because RGB_TO_GRAY does the gamma transform. */ |
4170 /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit | 4839 (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 && |
4171 * tables, we don't make a full table if we are reducing to 8-bit in | 4840 #endif |
4172 * the future. Note also how the gamma_16 tables are segmented so that | 4841 #if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\ |
4173 * we don't need to allocate > 64K chunks for a full 16-bit table. | 4842 defined(PNG_READ_ALPHA_MODE_SUPPORTED) |
4174 * | 4843 /* Because PNG_COMPOSE does the gamma transform if there is something to |
4175 * See the PNG extensions document for an integer algorithm for creating | 4844 * do (if there is an alpha channel or transparency.) |
4176 * the gamma tables. Maybe we will implement that here someday. | 4845 */ |
4177 * | 4846 !((png_ptr->transformations & PNG_COMPOSE) != 0 && |
4178 * We should only reach this point if | 4847 ((png_ptr->num_trans != 0) || |
4179 * | 4848 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) && |
4180 * the file_gamma is known (i.e., the gAMA or sRGB chunk is present, | 4849 #endif |
4181 * or the application has provided a file_gamma) | 4850 /* Because png_init_read_transformations transforms the palette, unless |
4182 * | 4851 * RGB_TO_GRAY will do the transform. |
4183 * AND | 4852 */ |
4184 * { | 4853 (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) |
4185 * the screen_gamma is known | 4854 png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); |
4186 * OR | 4855 #endif |
4187 * | 4856 |
4188 * RGB_to_gray transformation is being performed | 4857 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
4189 * } | 4858 if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 && |
4190 * | 4859 (png_ptr->transformations & PNG_COMPOSE) != 0 && |
4191 * AND | 4860 (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || |
4192 * { | 4861 row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) |
4193 * the screen_gamma is different from the reciprocal of the | 4862 png_do_strip_channel(row_info, png_ptr->row_buf + 1, |
4194 * file_gamma by more than the specified threshold | 4863 0 /* at_start == false, because SWAP_ALPHA happens later */); |
4195 * | 4864 #endif |
4196 * OR | 4865 |
4197 * | 4866 #ifdef PNG_READ_ALPHA_MODE_SUPPORTED |
4198 * a background color has been specified and the file_gamma | 4867 if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 && |
4199 * and screen_gamma are not 1.0, within the specified threshold. | 4868 (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0) |
4200 * } | 4869 png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr); |
4201 */ | 4870 #endif |
4202 | 4871 |
4203 void /* PRIVATE */ | 4872 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED |
4204 png_build_gamma_table(png_structp png_ptr) | 4873 if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0) |
4205 { | 4874 png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1); |
4206 png_debug(1, "in png_build_gamma_table"); | 4875 #endif |
4207 | 4876 |
4208 if (png_ptr->bit_depth <= 8) | 4877 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED |
4209 { | 4878 /* There is no harm in doing both of these because only one has any effect, |
4210 int i; | 4879 * by putting the 'scale' option first if the app asks for scale (either by |
4211 double g; | 4880 * calling the API or in a TRANSFORM flag) this is what happens. |
4212 | 4881 */ |
4213 if (png_ptr->screen_gamma > .000001) | 4882 if ((png_ptr->transformations & PNG_16_TO_8) != 0) |
4214 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); | 4883 png_do_chop(row_info, png_ptr->row_buf + 1); |
4215 | 4884 #endif |
4216 else | 4885 |
4217 g = 1.0; | 4886 #ifdef PNG_READ_QUANTIZE_SUPPORTED |
4218 | 4887 if ((png_ptr->transformations & PNG_QUANTIZE) != 0) |
4219 png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr, | 4888 { |
4220 (png_uint_32)256); | 4889 png_do_quantize(row_info, png_ptr->row_buf + 1, |
4221 | 4890 png_ptr->palette_lookup, png_ptr->quantize_index); |
4222 for (i = 0; i < 256; i++) | 4891 |
4223 { | 4892 if (row_info->rowbytes == 0) |
4224 png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0, | 4893 png_error(png_ptr, "png_do_quantize returned rowbytes=0"); |
4225 g) * 255.0 + .5); | 4894 } |
4226 } | 4895 #endif /* READ_QUANTIZE */ |
4227 | 4896 |
4228 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ | 4897 #ifdef PNG_READ_EXPAND_16_SUPPORTED |
4229 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) | 4898 /* Do the expansion now, after all the arithmetic has been done. Notice |
4230 if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY)) | 4899 * that previous transformations can handle the PNG_EXPAND_16 flag if this |
4231 { | 4900 * is efficient (particularly true in the case of gamma correction, where |
4232 | 4901 * better accuracy results faster!) |
4233 g = 1.0 / (png_ptr->gamma); | 4902 */ |
4234 | 4903 if ((png_ptr->transformations & PNG_EXPAND_16) != 0) |
4235 png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr, | 4904 png_do_expand_16(row_info, png_ptr->row_buf + 1); |
4236 (png_uint_32)256); | 4905 #endif |
4237 | 4906 |
4238 for (i = 0; i < 256; i++) | 4907 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
4239 { | 4908 /* NOTE: moved here in 1.5.4 (from much later in this list.) */ |
4240 png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0, | 4909 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 && |
4241 g) * 255.0 + .5); | 4910 (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0) |
4242 } | 4911 png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); |
4243 | 4912 #endif |
4244 | 4913 |
4245 png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr, | 4914 #ifdef PNG_READ_INVERT_SUPPORTED |
4246 (png_uint_32)256); | 4915 if ((png_ptr->transformations & PNG_INVERT_MONO) != 0) |
4247 | 4916 png_do_invert(row_info, png_ptr->row_buf + 1); |
4248 if (png_ptr->screen_gamma > 0.000001) | 4917 #endif |
4249 g = 1.0 / png_ptr->screen_gamma; | 4918 |
4250 | 4919 #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
4251 else | 4920 if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0) |
4252 g = png_ptr->gamma; /* Probably doing rgb_to_gray */ | 4921 png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1); |
4253 | 4922 #endif |
4254 for (i = 0; i < 256; i++) | 4923 |
4255 { | 4924 #ifdef PNG_READ_SHIFT_SUPPORTED |
4256 png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0, | 4925 if ((png_ptr->transformations & PNG_SHIFT) != 0) |
4257 g) * 255.0 + .5); | 4926 png_do_unshift(row_info, png_ptr->row_buf + 1, |
4258 | 4927 &(png_ptr->shift)); |
4259 } | 4928 #endif |
4260 } | 4929 |
4261 #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ | 4930 #ifdef PNG_READ_PACK_SUPPORTED |
4262 } | 4931 if ((png_ptr->transformations & PNG_PACK) != 0) |
4263 else | 4932 png_do_unpack(row_info, png_ptr->row_buf + 1); |
4264 { | 4933 #endif |
4265 double g; | 4934 |
4266 int i, j, shift, num; | 4935 #ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED |
4267 int sig_bit; | 4936 /* Added at libpng-1.5.10 */ |
4268 png_uint_32 ig; | 4937 if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && |
4269 | 4938 png_ptr->num_palette_max >= 0) |
4270 if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) | 4939 png_do_check_palette_indexes(png_ptr, row_info); |
4271 { | 4940 #endif |
4272 sig_bit = (int)png_ptr->sig_bit.red; | 4941 |
4273 | 4942 #ifdef PNG_READ_BGR_SUPPORTED |
4274 if ((int)png_ptr->sig_bit.green > sig_bit) | 4943 if ((png_ptr->transformations & PNG_BGR) != 0) |
4275 sig_bit = png_ptr->sig_bit.green; | 4944 png_do_bgr(row_info, png_ptr->row_buf + 1); |
4276 | 4945 #endif |
4277 if ((int)png_ptr->sig_bit.blue > sig_bit) | 4946 |
4278 sig_bit = png_ptr->sig_bit.blue; | 4947 #ifdef PNG_READ_PACKSWAP_SUPPORTED |
4279 } | 4948 if ((png_ptr->transformations & PNG_PACKSWAP) != 0) |
4280 else | 4949 png_do_packswap(row_info, png_ptr->row_buf + 1); |
4281 { | 4950 #endif |
4282 sig_bit = (int)png_ptr->sig_bit.gray; | 4951 |
4283 } | 4952 #ifdef PNG_READ_FILLER_SUPPORTED |
4284 | 4953 if ((png_ptr->transformations & PNG_FILLER) != 0) |
4285 if (sig_bit > 0) | 4954 png_do_read_filler(row_info, png_ptr->row_buf + 1, |
4286 shift = 16 - sig_bit; | 4955 (png_uint_32)png_ptr->filler, png_ptr->flags); |
4287 | 4956 #endif |
4288 else | 4957 |
4289 shift = 0; | 4958 #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED |
4290 | 4959 if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0) |
4291 if (png_ptr->transformations & PNG_16_TO_8) | 4960 png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1); |
4292 { | 4961 #endif |
4293 if (shift < (16 - PNG_MAX_GAMMA_8)) | 4962 |
4294 shift = (16 - PNG_MAX_GAMMA_8); | 4963 #ifdef PNG_READ_16BIT_SUPPORTED |
4295 } | 4964 #ifdef PNG_READ_SWAP_SUPPORTED |
4296 | 4965 if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0) |
4297 if (shift > 8) | 4966 png_do_swap(row_info, png_ptr->row_buf + 1); |
4298 shift = 8; | 4967 #endif |
4299 | 4968 #endif |
4300 if (shift < 0) | 4969 |
4301 shift = 0; | 4970 #ifdef PNG_READ_USER_TRANSFORM_SUPPORTED |
4302 | 4971 if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0) |
4303 png_ptr->gamma_shift = (png_byte)shift; | 4972 { |
4304 | 4973 if (png_ptr->read_user_transform_fn != NULL) |
4305 num = (1 << (8 - shift)); | 4974 (*(png_ptr->read_user_transform_fn)) /* User read transform function */ |
4306 | 4975 (png_ptr, /* png_ptr */ |
4307 if (png_ptr->screen_gamma > .000001) | 4976 row_info, /* row_info: */ |
4308 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); | 4977 /* png_uint_32 width; width of row */ |
4309 else | 4978 /* png_size_t rowbytes; number of bytes in row */ |
4310 g = 1.0; | 4979 /* png_byte color_type; color type of pixels */ |
4311 | 4980 /* png_byte bit_depth; bit depth of samples */ |
4312 png_ptr->gamma_16_table = (png_uint_16pp)png_calloc(png_ptr, | 4981 /* png_byte channels; number of channels (1-4) */ |
4313 (png_uint_32)(num * png_sizeof(png_uint_16p))); | 4982 /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
4314 | 4983 png_ptr->row_buf + 1); /* start of pixel data for row */ |
4315 if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND)) | 4984 #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED |
4316 { | 4985 if (png_ptr->user_transform_depth != 0) |
4317 double fin, fout; | 4986 row_info->bit_depth = png_ptr->user_transform_depth; |
4318 png_uint_32 last, max; | 4987 |
4319 | 4988 if (png_ptr->user_transform_channels != 0) |
4320 for (i = 0; i < num; i++) | 4989 row_info->channels = png_ptr->user_transform_channels; |
4321 { | 4990 #endif |
4322 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, | 4991 row_info->pixel_depth = (png_byte)(row_info->bit_depth * |
4323 (png_uint_32)(256 * png_sizeof(png_uint_16))); | 4992 row_info->channels); |
4324 } | 4993 |
4325 | 4994 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width); |
4326 g = 1.0 / g; | 4995 } |
4327 last = 0; | 4996 #endif |
4328 for (i = 0; i < 256; i++) | |
4329 { | |
4330 fout = ((double)i + 0.5) / 256.0; | |
4331 fin = pow(fout, g); | |
4332 max = (png_uint_32)(fin * (double)((png_uint_32)num << 8)); | |
4333 while (last <= max) | |
4334 { | |
4335 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] | |
4336 [(int)(last >> (8 - shift))] = (png_uint_16)( | |
4337 (png_uint_16)i | ((png_uint_16)i << 8)); | |
4338 last++; | |
4339 } | |
4340 } | |
4341 while (last < ((png_uint_32)num << 8)) | |
4342 { | |
4343 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] | |
4344 [(int)(last >> (8 - shift))] = (png_uint_16)65535L; | |
4345 last++; | |
4346 } | |
4347 } | |
4348 else | |
4349 { | |
4350 for (i = 0; i < num; i++) | |
4351 { | |
4352 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, | |
4353 (png_uint_32)(256 * png_sizeof(png_uint_16))); | |
4354 | |
4355 ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4); | |
4356 | |
4357 for (j = 0; j < 256; j++) | |
4358 { | |
4359 png_ptr->gamma_16_table[i][j] = | |
4360 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / | |
4361 65535.0, g) * 65535.0 + .5); | |
4362 } | |
4363 } | |
4364 } | |
4365 | |
4366 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ | |
4367 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) | |
4368 if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) | |
4369 { | |
4370 | |
4371 g = 1.0 / (png_ptr->gamma); | |
4372 | |
4373 png_ptr->gamma_16_to_1 = (png_uint_16pp)png_calloc(png_ptr, | |
4374 (png_uint_32)(num * png_sizeof(png_uint_16p ))); | |
4375 | |
4376 for (i = 0; i < num; i++) | |
4377 { | |
4378 png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr, | |
4379 (png_uint_32)(256 * png_sizeof(png_uint_16))); | |
4380 | |
4381 ig = (((png_uint_32)i * | |
4382 (png_uint_32)png_gamma_shift[shift]) >> 4); | |
4383 for (j = 0; j < 256; j++) | |
4384 { | |
4385 png_ptr->gamma_16_to_1[i][j] = | |
4386 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / | |
4387 65535.0, g) * 65535.0 + .5); | |
4388 } | |
4389 } | |
4390 | |
4391 if (png_ptr->screen_gamma > 0.000001) | |
4392 g = 1.0 / png_ptr->screen_gamma; | |
4393 | |
4394 else | |
4395 g = png_ptr->gamma; /* Probably doing rgb_to_gray */ | |
4396 | |
4397 png_ptr->gamma_16_from_1 = (png_uint_16pp)png_calloc(png_ptr, | |
4398 (png_uint_32)(num * png_sizeof(png_uint_16p))); | |
4399 | |
4400 for (i = 0; i < num; i++) | |
4401 { | |
4402 png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr, | |
4403 (png_uint_32)(256 * png_sizeof(png_uint_16))); | |
4404 | |
4405 ig = (((png_uint_32)i * | |
4406 (png_uint_32)png_gamma_shift[shift]) >> 4); | |
4407 | |
4408 for (j = 0; j < 256; j++) | |
4409 { | |
4410 png_ptr->gamma_16_from_1[i][j] = | |
4411 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / | |
4412 65535.0, g) * 65535.0 + .5); | |
4413 } | |
4414 } | |
4415 } | |
4416 #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ | |
4417 } | |
4418 } | 4997 } |
4419 #endif | 4998 |
4420 /* To do: install integer version of png_build_gamma_table here */ | 4999 #endif /* READ_TRANSFORMS */ |
4421 #endif | 5000 #endif /* READ */ |
4422 | |
4423 #ifdef PNG_MNG_FEATURES_SUPPORTED | |
4424 /* Undoes intrapixel differencing */ | |
4425 void /* PRIVATE */ | |
4426 png_do_read_intrapixel(png_row_infop row_info, png_bytep row) | |
4427 { | |
4428 png_debug(1, "in png_do_read_intrapixel"); | |
4429 | |
4430 if ( | |
4431 #ifdef PNG_USELESS_TESTS_SUPPORTED | |
4432 row != NULL && row_info != NULL && | |
4433 #endif | |
4434 (row_info->color_type & PNG_COLOR_MASK_COLOR)) | |
4435 { | |
4436 int bytes_per_pixel; | |
4437 png_uint_32 row_width = row_info->width; | |
4438 if (row_info->bit_depth == 8) | |
4439 { | |
4440 png_bytep rp; | |
4441 png_uint_32 i; | |
4442 | |
4443 if (row_info->color_type == PNG_COLOR_TYPE_RGB) | |
4444 bytes_per_pixel = 3; | |
4445 | |
4446 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | |
4447 bytes_per_pixel = 4; | |
4448 | |
4449 else | |
4450 return; | |
4451 | |
4452 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) | |
4453 { | |
4454 *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff); | |
4455 *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff); | |
4456 } | |
4457 } | |
4458 else if (row_info->bit_depth == 16) | |
4459 { | |
4460 png_bytep rp; | |
4461 png_uint_32 i; | |
4462 | |
4463 if (row_info->color_type == PNG_COLOR_TYPE_RGB) | |
4464 bytes_per_pixel = 6; | |
4465 | |
4466 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) | |
4467 bytes_per_pixel = 8; | |
4468 | |
4469 else | |
4470 return; | |
4471 | |
4472 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) | |
4473 { | |
4474 png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); | |
4475 png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); | |
4476 png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); | |
4477 png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL); | |
4478 png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL); | |
4479 *(rp ) = (png_byte)((red >> 8) & 0xff); | |
4480 *(rp+1) = (png_byte)(red & 0xff); | |
4481 *(rp+4) = (png_byte)((blue >> 8) & 0xff); | |
4482 *(rp+5) = (png_byte)(blue & 0xff); | |
4483 } | |
4484 } | |
4485 } | |
4486 } | |
4487 #endif /* PNG_MNG_FEATURES_SUPPORTED */ | |
4488 #endif /* PNG_READ_SUPPORTED */ | |
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