| Index: third_party/libpng/pngrtran.c
|
| diff --git a/third_party/libpng/pngrtran.c b/third_party/libpng/pngrtran.c
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..b65abbdefd09097b2f3ba9d56184c9d9fd234c25
|
| --- /dev/null
|
| +++ b/third_party/libpng/pngrtran.c
|
| @@ -0,0 +1,5000 @@
|
| +
|
| +/* pngrtran.c - transforms the data in a row for PNG readers
|
| + *
|
| + * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
|
| + * Copyright (c) 1998-2002,2004,2006-2016 Glenn Randers-Pehrson
|
| + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
|
| + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
|
| + *
|
| + * This code is released under the libpng license.
|
| + * For conditions of distribution and use, see the disclaimer
|
| + * and license in png.h
|
| + *
|
| + * This file contains functions optionally called by an application
|
| + * in order to tell libpng how to handle data when reading a PNG.
|
| + * Transformations that are used in both reading and writing are
|
| + * in pngtrans.c.
|
| + */
|
| +
|
| +#include "pngpriv.h"
|
| +
|
| +#ifdef PNG_READ_SUPPORTED
|
| +
|
| +/* Set the action on getting a CRC error for an ancillary or critical chunk. */
|
| +void PNGAPI
|
| +png_set_crc_action(png_structrp png_ptr, int crit_action, int ancil_action)
|
| +{
|
| + png_debug(1, "in png_set_crc_action");
|
| +
|
| + if (png_ptr == NULL)
|
| + return;
|
| +
|
| + /* Tell libpng how we react to CRC errors in critical chunks */
|
| + switch (crit_action)
|
| + {
|
| + case PNG_CRC_NO_CHANGE: /* Leave setting as is */
|
| + break;
|
| +
|
| + case PNG_CRC_WARN_USE: /* Warn/use data */
|
| + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
|
| + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
|
| + break;
|
| +
|
| + case PNG_CRC_QUIET_USE: /* Quiet/use data */
|
| + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
|
| + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
|
| + PNG_FLAG_CRC_CRITICAL_IGNORE;
|
| + break;
|
| +
|
| + case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
|
| + png_warning(png_ptr,
|
| + "Can't discard critical data on CRC error");
|
| + case PNG_CRC_ERROR_QUIT: /* Error/quit */
|
| +
|
| + case PNG_CRC_DEFAULT:
|
| + default:
|
| + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
|
| + break;
|
| + }
|
| +
|
| + /* Tell libpng how we react to CRC errors in ancillary chunks */
|
| + switch (ancil_action)
|
| + {
|
| + case PNG_CRC_NO_CHANGE: /* Leave setting as is */
|
| + break;
|
| +
|
| + case PNG_CRC_WARN_USE: /* Warn/use data */
|
| + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
|
| + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
|
| + break;
|
| +
|
| + case PNG_CRC_QUIET_USE: /* Quiet/use data */
|
| + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
|
| + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
|
| + PNG_FLAG_CRC_ANCILLARY_NOWARN;
|
| + break;
|
| +
|
| + case PNG_CRC_ERROR_QUIT: /* Error/quit */
|
| + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
|
| + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
|
| + break;
|
| +
|
| + case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
|
| +
|
| + case PNG_CRC_DEFAULT:
|
| + default:
|
| + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
|
| + break;
|
| + }
|
| +}
|
| +
|
| +#ifdef PNG_READ_TRANSFORMS_SUPPORTED
|
| +/* Is it OK to set a transformation now? Only if png_start_read_image or
|
| + * png_read_update_info have not been called. It is not necessary for the IHDR
|
| + * to have been read in all cases; the need_IHDR parameter allows for this
|
| + * check too.
|
| + */
|
| +static int
|
| +png_rtran_ok(png_structrp png_ptr, int need_IHDR)
|
| +{
|
| + if (png_ptr != NULL)
|
| + {
|
| + if ((png_ptr->flags & PNG_FLAG_ROW_INIT) != 0)
|
| + png_app_error(png_ptr,
|
| + "invalid after png_start_read_image or png_read_update_info");
|
| +
|
| + else if (need_IHDR && (png_ptr->mode & PNG_HAVE_IHDR) == 0)
|
| + png_app_error(png_ptr, "invalid before the PNG header has been read");
|
| +
|
| + else
|
| + {
|
| + /* Turn on failure to initialize correctly for all transforms. */
|
| + png_ptr->flags |= PNG_FLAG_DETECT_UNINITIALIZED;
|
| +
|
| + return 1; /* Ok */
|
| + }
|
| + }
|
| +
|
| + return 0; /* no png_error possible! */
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
| +/* Handle alpha and tRNS via a background color */
|
| +void PNGFAPI
|
| +png_set_background_fixed(png_structrp png_ptr,
|
| + png_const_color_16p background_color, int background_gamma_code,
|
| + int need_expand, png_fixed_point background_gamma)
|
| +{
|
| + png_debug(1, "in png_set_background_fixed");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0 || background_color == NULL)
|
| + return;
|
| +
|
| + if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
|
| + {
|
| + png_warning(png_ptr, "Application must supply a known background gamma");
|
| + return;
|
| + }
|
| +
|
| + png_ptr->transformations |= PNG_COMPOSE | PNG_STRIP_ALPHA;
|
| + png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| +
|
| + png_ptr->background = *background_color;
|
| + png_ptr->background_gamma = background_gamma;
|
| + png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
|
| + if (need_expand != 0)
|
| + png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
|
| + else
|
| + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
|
| +}
|
| +
|
| +# ifdef PNG_FLOATING_POINT_SUPPORTED
|
| +void PNGAPI
|
| +png_set_background(png_structrp png_ptr,
|
| + png_const_color_16p background_color, int background_gamma_code,
|
| + int need_expand, double background_gamma)
|
| +{
|
| + png_set_background_fixed(png_ptr, background_color, background_gamma_code,
|
| + need_expand, png_fixed(png_ptr, background_gamma, "png_set_background"));
|
| +}
|
| +# endif /* FLOATING_POINT */
|
| +#endif /* READ_BACKGROUND */
|
| +
|
| +/* Scale 16-bit depth files to 8-bit depth. If both of these are set then the
|
| + * one that pngrtran does first (scale) happens. This is necessary to allow the
|
| + * TRANSFORM and API behavior to be somewhat consistent, and it's simpler.
|
| + */
|
| +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
| +void PNGAPI
|
| +png_set_scale_16(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_scale_16");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= PNG_SCALE_16_TO_8;
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
| +/* Chop 16-bit depth files to 8-bit depth */
|
| +void PNGAPI
|
| +png_set_strip_16(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_strip_16");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= PNG_16_TO_8;
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
| +void PNGAPI
|
| +png_set_strip_alpha(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_strip_alpha");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= PNG_STRIP_ALPHA;
|
| +}
|
| +#endif
|
| +
|
| +#if defined(PNG_READ_ALPHA_MODE_SUPPORTED) || defined(PNG_READ_GAMMA_SUPPORTED)
|
| +static png_fixed_point
|
| +translate_gamma_flags(png_structrp png_ptr, png_fixed_point output_gamma,
|
| + int is_screen)
|
| +{
|
| + /* Check for flag values. The main reason for having the old Mac value as a
|
| + * flag is that it is pretty near impossible to work out what the correct
|
| + * value is from Apple documentation - a working Mac system is needed to
|
| + * discover the value!
|
| + */
|
| + if (output_gamma == PNG_DEFAULT_sRGB ||
|
| + output_gamma == PNG_FP_1 / PNG_DEFAULT_sRGB)
|
| + {
|
| + /* If there is no sRGB support this just sets the gamma to the standard
|
| + * sRGB value. (This is a side effect of using this function!)
|
| + */
|
| +# ifdef PNG_READ_sRGB_SUPPORTED
|
| + png_ptr->flags |= PNG_FLAG_ASSUME_sRGB;
|
| +# else
|
| + PNG_UNUSED(png_ptr)
|
| +# endif
|
| + if (is_screen != 0)
|
| + output_gamma = PNG_GAMMA_sRGB;
|
| + else
|
| + output_gamma = PNG_GAMMA_sRGB_INVERSE;
|
| + }
|
| +
|
| + else if (output_gamma == PNG_GAMMA_MAC_18 ||
|
| + output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
|
| + {
|
| + if (is_screen != 0)
|
| + output_gamma = PNG_GAMMA_MAC_OLD;
|
| + else
|
| + output_gamma = PNG_GAMMA_MAC_INVERSE;
|
| + }
|
| +
|
| + return output_gamma;
|
| +}
|
| +
|
| +# ifdef PNG_FLOATING_POINT_SUPPORTED
|
| +static png_fixed_point
|
| +convert_gamma_value(png_structrp png_ptr, double output_gamma)
|
| +{
|
| + /* The following silently ignores cases where fixed point (times 100,000)
|
| + * gamma values are passed to the floating point API. This is safe and it
|
| + * means the fixed point constants work just fine with the floating point
|
| + * API. The alternative would just lead to undetected errors and spurious
|
| + * bug reports. Negative values fail inside the _fixed API unless they
|
| + * correspond to the flag values.
|
| + */
|
| + if (output_gamma > 0 && output_gamma < 128)
|
| + output_gamma *= PNG_FP_1;
|
| +
|
| + /* This preserves -1 and -2 exactly: */
|
| + output_gamma = floor(output_gamma + .5);
|
| +
|
| + if (output_gamma > PNG_FP_MAX || output_gamma < PNG_FP_MIN)
|
| + png_fixed_error(png_ptr, "gamma value");
|
| +
|
| + return (png_fixed_point)output_gamma;
|
| +}
|
| +# endif
|
| +#endif /* READ_ALPHA_MODE || READ_GAMMA */
|
| +
|
| +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
| +void PNGFAPI
|
| +png_set_alpha_mode_fixed(png_structrp png_ptr, int mode,
|
| + png_fixed_point output_gamma)
|
| +{
|
| + int compose = 0;
|
| + png_fixed_point file_gamma;
|
| +
|
| + png_debug(1, "in png_set_alpha_mode");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + output_gamma = translate_gamma_flags(png_ptr, output_gamma, 1/*screen*/);
|
| +
|
| + /* Validate the value to ensure it is in a reasonable range. The value
|
| + * is expected to be 1 or greater, but this range test allows for some
|
| + * viewing correction values. The intent is to weed out users of this API
|
| + * who use the inverse of the gamma value accidentally! Since some of these
|
| + * values are reasonable this may have to be changed:
|
| + *
|
| + * 1.6.x: changed from 0.07..3 to 0.01..100 (to accomodate the optimal 16-bit
|
| + * gamma of 36, and its reciprocal.)
|
| + */
|
| + if (output_gamma < 1000 || output_gamma > 10000000)
|
| + png_error(png_ptr, "output gamma out of expected range");
|
| +
|
| + /* The default file gamma is the inverse of the output gamma; the output
|
| + * gamma may be changed below so get the file value first:
|
| + */
|
| + file_gamma = png_reciprocal(output_gamma);
|
| +
|
| + /* There are really 8 possibilities here, composed of any combination
|
| + * of:
|
| + *
|
| + * premultiply the color channels
|
| + * do not encode non-opaque pixels
|
| + * encode the alpha as well as the color channels
|
| + *
|
| + * The differences disappear if the input/output ('screen') gamma is 1.0,
|
| + * because then the encoding is a no-op and there is only the choice of
|
| + * premultiplying the color channels or not.
|
| + *
|
| + * png_set_alpha_mode and png_set_background interact because both use
|
| + * png_compose to do the work. Calling both is only useful when
|
| + * png_set_alpha_mode is used to set the default mode - PNG_ALPHA_PNG - along
|
| + * with a default gamma value. Otherwise PNG_COMPOSE must not be set.
|
| + */
|
| + switch (mode)
|
| + {
|
| + case PNG_ALPHA_PNG: /* default: png standard */
|
| + /* No compose, but it may be set by png_set_background! */
|
| + png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| + break;
|
| +
|
| + case PNG_ALPHA_ASSOCIATED: /* color channels premultiplied */
|
| + compose = 1;
|
| + png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| + /* The output is linear: */
|
| + output_gamma = PNG_FP_1;
|
| + break;
|
| +
|
| + case PNG_ALPHA_OPTIMIZED: /* associated, non-opaque pixels linear */
|
| + compose = 1;
|
| + png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
| + png_ptr->flags |= PNG_FLAG_OPTIMIZE_ALPHA;
|
| + /* output_gamma records the encoding of opaque pixels! */
|
| + break;
|
| +
|
| + case PNG_ALPHA_BROKEN: /* associated, non-linear, alpha encoded */
|
| + compose = 1;
|
| + png_ptr->transformations |= PNG_ENCODE_ALPHA;
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| + break;
|
| +
|
| + default:
|
| + png_error(png_ptr, "invalid alpha mode");
|
| + }
|
| +
|
| + /* Only set the default gamma if the file gamma has not been set (this has
|
| + * the side effect that the gamma in a second call to png_set_alpha_mode will
|
| + * be ignored.)
|
| + */
|
| + if (png_ptr->colorspace.gamma == 0)
|
| + {
|
| + png_ptr->colorspace.gamma = file_gamma;
|
| + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
|
| + }
|
| +
|
| + /* But always set the output gamma: */
|
| + png_ptr->screen_gamma = output_gamma;
|
| +
|
| + /* Finally, if pre-multiplying, set the background fields to achieve the
|
| + * desired result.
|
| + */
|
| + if (compose != 0)
|
| + {
|
| + /* And obtain alpha pre-multiplication by composing on black: */
|
| + memset(&png_ptr->background, 0, (sizeof png_ptr->background));
|
| + png_ptr->background_gamma = png_ptr->colorspace.gamma; /* just in case */
|
| + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_FILE;
|
| + png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
|
| +
|
| + if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
| + png_error(png_ptr,
|
| + "conflicting calls to set alpha mode and background");
|
| +
|
| + png_ptr->transformations |= PNG_COMPOSE;
|
| + }
|
| +}
|
| +
|
| +# ifdef PNG_FLOATING_POINT_SUPPORTED
|
| +void PNGAPI
|
| +png_set_alpha_mode(png_structrp png_ptr, int mode, double output_gamma)
|
| +{
|
| + png_set_alpha_mode_fixed(png_ptr, mode, convert_gamma_value(png_ptr,
|
| + output_gamma));
|
| +}
|
| +# endif
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
| +/* Dither file to 8-bit. Supply a palette, the current number
|
| + * of elements in the palette, the maximum number of elements
|
| + * allowed, and a histogram if possible. If the current number
|
| + * of colors is greater than the maximum number, the palette will be
|
| + * modified to fit in the maximum number. "full_quantize" indicates
|
| + * whether we need a quantizing cube set up for RGB images, or if we
|
| + * simply are reducing the number of colors in a paletted image.
|
| + */
|
| +
|
| +typedef struct png_dsort_struct
|
| +{
|
| + struct png_dsort_struct * next;
|
| + png_byte left;
|
| + png_byte right;
|
| +} png_dsort;
|
| +typedef png_dsort * png_dsortp;
|
| +typedef png_dsort * * png_dsortpp;
|
| +
|
| +void PNGAPI
|
| +png_set_quantize(png_structrp png_ptr, png_colorp palette,
|
| + int num_palette, int maximum_colors, png_const_uint_16p histogram,
|
| + int full_quantize)
|
| +{
|
| + png_debug(1, "in png_set_quantize");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= PNG_QUANTIZE;
|
| +
|
| + if (full_quantize == 0)
|
| + {
|
| + int i;
|
| +
|
| + png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
|
| + (png_uint_32)(num_palette * (sizeof (png_byte))));
|
| + for (i = 0; i < num_palette; i++)
|
| + png_ptr->quantize_index[i] = (png_byte)i;
|
| + }
|
| +
|
| + if (num_palette > maximum_colors)
|
| + {
|
| + if (histogram != NULL)
|
| + {
|
| + /* This is easy enough, just throw out the least used colors.
|
| + * Perhaps not the best solution, but good enough.
|
| + */
|
| +
|
| + int i;
|
| +
|
| + /* Initialize an array to sort colors */
|
| + png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
|
| + (png_uint_32)(num_palette * (sizeof (png_byte))));
|
| +
|
| + /* Initialize the quantize_sort array */
|
| + for (i = 0; i < num_palette; i++)
|
| + png_ptr->quantize_sort[i] = (png_byte)i;
|
| +
|
| + /* Find the least used palette entries by starting a
|
| + * bubble sort, and running it until we have sorted
|
| + * out enough colors. Note that we don't care about
|
| + * sorting all the colors, just finding which are
|
| + * least used.
|
| + */
|
| +
|
| + for (i = num_palette - 1; i >= maximum_colors; i--)
|
| + {
|
| + int done; /* To stop early if the list is pre-sorted */
|
| + int j;
|
| +
|
| + done = 1;
|
| + for (j = 0; j < i; j++)
|
| + {
|
| + if (histogram[png_ptr->quantize_sort[j]]
|
| + < histogram[png_ptr->quantize_sort[j + 1]])
|
| + {
|
| + png_byte t;
|
| +
|
| + t = png_ptr->quantize_sort[j];
|
| + png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
|
| + png_ptr->quantize_sort[j + 1] = t;
|
| + done = 0;
|
| + }
|
| + }
|
| +
|
| + if (done != 0)
|
| + break;
|
| + }
|
| +
|
| + /* Swap the palette around, and set up a table, if necessary */
|
| + if (full_quantize != 0)
|
| + {
|
| + int j = num_palette;
|
| +
|
| + /* Put all the useful colors within the max, but don't
|
| + * move the others.
|
| + */
|
| + for (i = 0; i < maximum_colors; i++)
|
| + {
|
| + if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
|
| + {
|
| + do
|
| + j--;
|
| + while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
|
| +
|
| + palette[i] = palette[j];
|
| + }
|
| + }
|
| + }
|
| + else
|
| + {
|
| + int j = num_palette;
|
| +
|
| + /* Move all the used colors inside the max limit, and
|
| + * develop a translation table.
|
| + */
|
| + for (i = 0; i < maximum_colors; i++)
|
| + {
|
| + /* Only move the colors we need to */
|
| + if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
|
| + {
|
| + png_color tmp_color;
|
| +
|
| + do
|
| + j--;
|
| + while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
|
| +
|
| + tmp_color = palette[j];
|
| + palette[j] = palette[i];
|
| + palette[i] = tmp_color;
|
| + /* Indicate where the color went */
|
| + png_ptr->quantize_index[j] = (png_byte)i;
|
| + png_ptr->quantize_index[i] = (png_byte)j;
|
| + }
|
| + }
|
| +
|
| + /* Find closest color for those colors we are not using */
|
| + for (i = 0; i < num_palette; i++)
|
| + {
|
| + if ((int)png_ptr->quantize_index[i] >= maximum_colors)
|
| + {
|
| + int min_d, k, min_k, d_index;
|
| +
|
| + /* Find the closest color to one we threw out */
|
| + d_index = png_ptr->quantize_index[i];
|
| + min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
|
| + for (k = 1, min_k = 0; k < maximum_colors; k++)
|
| + {
|
| + int d;
|
| +
|
| + d = PNG_COLOR_DIST(palette[d_index], palette[k]);
|
| +
|
| + if (d < min_d)
|
| + {
|
| + min_d = d;
|
| + min_k = k;
|
| + }
|
| + }
|
| + /* Point to closest color */
|
| + png_ptr->quantize_index[i] = (png_byte)min_k;
|
| + }
|
| + }
|
| + }
|
| + png_free(png_ptr, png_ptr->quantize_sort);
|
| + png_ptr->quantize_sort = NULL;
|
| + }
|
| + else
|
| + {
|
| + /* This is much harder to do simply (and quickly). Perhaps
|
| + * we need to go through a median cut routine, but those
|
| + * don't always behave themselves with only a few colors
|
| + * as input. So we will just find the closest two colors,
|
| + * and throw out one of them (chosen somewhat randomly).
|
| + * [We don't understand this at all, so if someone wants to
|
| + * work on improving it, be our guest - AED, GRP]
|
| + */
|
| + int i;
|
| + int max_d;
|
| + int num_new_palette;
|
| + png_dsortp t;
|
| + png_dsortpp hash;
|
| +
|
| + t = NULL;
|
| +
|
| + /* Initialize palette index arrays */
|
| + png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
|
| + (png_uint_32)(num_palette * (sizeof (png_byte))));
|
| + png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
|
| + (png_uint_32)(num_palette * (sizeof (png_byte))));
|
| +
|
| + /* Initialize the sort array */
|
| + for (i = 0; i < num_palette; i++)
|
| + {
|
| + png_ptr->index_to_palette[i] = (png_byte)i;
|
| + png_ptr->palette_to_index[i] = (png_byte)i;
|
| + }
|
| +
|
| + hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
|
| + (sizeof (png_dsortp))));
|
| +
|
| + num_new_palette = num_palette;
|
| +
|
| + /* Initial wild guess at how far apart the farthest pixel
|
| + * pair we will be eliminating will be. Larger
|
| + * numbers mean more areas will be allocated, Smaller
|
| + * numbers run the risk of not saving enough data, and
|
| + * having to do this all over again.
|
| + *
|
| + * I have not done extensive checking on this number.
|
| + */
|
| + max_d = 96;
|
| +
|
| + while (num_new_palette > maximum_colors)
|
| + {
|
| + for (i = 0; i < num_new_palette - 1; i++)
|
| + {
|
| + int j;
|
| +
|
| + for (j = i + 1; j < num_new_palette; j++)
|
| + {
|
| + int d;
|
| +
|
| + d = PNG_COLOR_DIST(palette[i], palette[j]);
|
| +
|
| + if (d <= max_d)
|
| + {
|
| +
|
| + t = (png_dsortp)png_malloc_warn(png_ptr,
|
| + (png_uint_32)(sizeof (png_dsort)));
|
| +
|
| + if (t == NULL)
|
| + break;
|
| +
|
| + t->next = hash[d];
|
| + t->left = (png_byte)i;
|
| + t->right = (png_byte)j;
|
| + hash[d] = t;
|
| + }
|
| + }
|
| + if (t == NULL)
|
| + break;
|
| + }
|
| +
|
| + if (t != NULL)
|
| + for (i = 0; i <= max_d; i++)
|
| + {
|
| + if (hash[i] != NULL)
|
| + {
|
| + png_dsortp p;
|
| +
|
| + for (p = hash[i]; p; p = p->next)
|
| + {
|
| + if ((int)png_ptr->index_to_palette[p->left]
|
| + < num_new_palette &&
|
| + (int)png_ptr->index_to_palette[p->right]
|
| + < num_new_palette)
|
| + {
|
| + int j, next_j;
|
| +
|
| + if (num_new_palette & 0x01)
|
| + {
|
| + j = p->left;
|
| + next_j = p->right;
|
| + }
|
| + else
|
| + {
|
| + j = p->right;
|
| + next_j = p->left;
|
| + }
|
| +
|
| + num_new_palette--;
|
| + palette[png_ptr->index_to_palette[j]]
|
| + = palette[num_new_palette];
|
| + if (full_quantize == 0)
|
| + {
|
| + int k;
|
| +
|
| + for (k = 0; k < num_palette; k++)
|
| + {
|
| + if (png_ptr->quantize_index[k] ==
|
| + png_ptr->index_to_palette[j])
|
| + png_ptr->quantize_index[k] =
|
| + png_ptr->index_to_palette[next_j];
|
| +
|
| + if ((int)png_ptr->quantize_index[k] ==
|
| + num_new_palette)
|
| + png_ptr->quantize_index[k] =
|
| + png_ptr->index_to_palette[j];
|
| + }
|
| + }
|
| +
|
| + png_ptr->index_to_palette[png_ptr->palette_to_index
|
| + [num_new_palette]] = png_ptr->index_to_palette[j];
|
| +
|
| + png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
|
| + = png_ptr->palette_to_index[num_new_palette];
|
| +
|
| + png_ptr->index_to_palette[j] =
|
| + (png_byte)num_new_palette;
|
| +
|
| + png_ptr->palette_to_index[num_new_palette] =
|
| + (png_byte)j;
|
| + }
|
| + if (num_new_palette <= maximum_colors)
|
| + break;
|
| + }
|
| + if (num_new_palette <= maximum_colors)
|
| + break;
|
| + }
|
| + }
|
| +
|
| + for (i = 0; i < 769; i++)
|
| + {
|
| + if (hash[i] != NULL)
|
| + {
|
| + png_dsortp p = hash[i];
|
| + while (p)
|
| + {
|
| + t = p->next;
|
| + png_free(png_ptr, p);
|
| + p = t;
|
| + }
|
| + }
|
| + hash[i] = 0;
|
| + }
|
| + max_d += 96;
|
| + }
|
| + png_free(png_ptr, hash);
|
| + png_free(png_ptr, png_ptr->palette_to_index);
|
| + png_free(png_ptr, png_ptr->index_to_palette);
|
| + png_ptr->palette_to_index = NULL;
|
| + png_ptr->index_to_palette = NULL;
|
| + }
|
| + num_palette = maximum_colors;
|
| + }
|
| + if (png_ptr->palette == NULL)
|
| + {
|
| + png_ptr->palette = palette;
|
| + }
|
| + png_ptr->num_palette = (png_uint_16)num_palette;
|
| +
|
| + if (full_quantize != 0)
|
| + {
|
| + int i;
|
| + png_bytep distance;
|
| + int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
|
| + PNG_QUANTIZE_BLUE_BITS;
|
| + int num_red = (1 << PNG_QUANTIZE_RED_BITS);
|
| + int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
|
| + int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
|
| + png_size_t num_entries = ((png_size_t)1 << total_bits);
|
| +
|
| + png_ptr->palette_lookup = (png_bytep)png_calloc(png_ptr,
|
| + (png_uint_32)(num_entries * (sizeof (png_byte))));
|
| +
|
| + distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
|
| + (sizeof (png_byte))));
|
| +
|
| + memset(distance, 0xff, num_entries * (sizeof (png_byte)));
|
| +
|
| + for (i = 0; i < num_palette; i++)
|
| + {
|
| + int ir, ig, ib;
|
| + int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
|
| + int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
|
| + int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
|
| +
|
| + for (ir = 0; ir < num_red; ir++)
|
| + {
|
| + /* int dr = abs(ir - r); */
|
| + int dr = ((ir > r) ? ir - r : r - ir);
|
| + int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
|
| + PNG_QUANTIZE_GREEN_BITS));
|
| +
|
| + for (ig = 0; ig < num_green; ig++)
|
| + {
|
| + /* int dg = abs(ig - g); */
|
| + int dg = ((ig > g) ? ig - g : g - ig);
|
| + int dt = dr + dg;
|
| + int dm = ((dr > dg) ? dr : dg);
|
| + int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
|
| +
|
| + for (ib = 0; ib < num_blue; ib++)
|
| + {
|
| + int d_index = index_g | ib;
|
| + /* int db = abs(ib - b); */
|
| + int db = ((ib > b) ? ib - b : b - ib);
|
| + int dmax = ((dm > db) ? dm : db);
|
| + int d = dmax + dt + db;
|
| +
|
| + if (d < (int)distance[d_index])
|
| + {
|
| + distance[d_index] = (png_byte)d;
|
| + png_ptr->palette_lookup[d_index] = (png_byte)i;
|
| + }
|
| + }
|
| + }
|
| + }
|
| + }
|
| +
|
| + png_free(png_ptr, distance);
|
| + }
|
| +}
|
| +#endif /* READ_QUANTIZE */
|
| +
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| +void PNGFAPI
|
| +png_set_gamma_fixed(png_structrp png_ptr, png_fixed_point scrn_gamma,
|
| + png_fixed_point file_gamma)
|
| +{
|
| + png_debug(1, "in png_set_gamma_fixed");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + /* New in libpng-1.5.4 - reserve particular negative values as flags. */
|
| + scrn_gamma = translate_gamma_flags(png_ptr, scrn_gamma, 1/*screen*/);
|
| + file_gamma = translate_gamma_flags(png_ptr, file_gamma, 0/*file*/);
|
| +
|
| + /* Checking the gamma values for being >0 was added in 1.5.4 along with the
|
| + * premultiplied alpha support; this actually hides an undocumented feature
|
| + * of the previous implementation which allowed gamma processing to be
|
| + * disabled in background handling. There is no evidence (so far) that this
|
| + * was being used; however, png_set_background itself accepted and must still
|
| + * accept '0' for the gamma value it takes, because it isn't always used.
|
| + *
|
| + * Since this is an API change (albeit a very minor one that removes an
|
| + * undocumented API feature) the following checks were only enabled in
|
| + * libpng-1.6.0.
|
| + */
|
| + if (file_gamma <= 0)
|
| + png_error(png_ptr, "invalid file gamma in png_set_gamma");
|
| +
|
| + if (scrn_gamma <= 0)
|
| + png_error(png_ptr, "invalid screen gamma in png_set_gamma");
|
| +
|
| + /* Set the gamma values unconditionally - this overrides the value in the PNG
|
| + * file if a gAMA chunk was present. png_set_alpha_mode provides a
|
| + * different, easier, way to default the file gamma.
|
| + */
|
| + png_ptr->colorspace.gamma = file_gamma;
|
| + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
|
| + png_ptr->screen_gamma = scrn_gamma;
|
| +}
|
| +
|
| +# ifdef PNG_FLOATING_POINT_SUPPORTED
|
| +void PNGAPI
|
| +png_set_gamma(png_structrp png_ptr, double scrn_gamma, double file_gamma)
|
| +{
|
| + png_set_gamma_fixed(png_ptr, convert_gamma_value(png_ptr, scrn_gamma),
|
| + convert_gamma_value(png_ptr, file_gamma));
|
| +}
|
| +# endif /* FLOATING_POINT */
|
| +#endif /* READ_GAMMA */
|
| +
|
| +#ifdef PNG_READ_EXPAND_SUPPORTED
|
| +/* Expand paletted images to RGB, expand grayscale images of
|
| + * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
|
| + * to alpha channels.
|
| + */
|
| +void PNGAPI
|
| +png_set_expand(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_expand");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
| +}
|
| +
|
| +/* GRR 19990627: the following three functions currently are identical
|
| + * to png_set_expand(). However, it is entirely reasonable that someone
|
| + * might wish to expand an indexed image to RGB but *not* expand a single,
|
| + * fully transparent palette entry to a full alpha channel--perhaps instead
|
| + * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
|
| + * the transparent color with a particular RGB value, or drop tRNS entirely.
|
| + * IOW, a future version of the library may make the transformations flag
|
| + * a bit more fine-grained, with separate bits for each of these three
|
| + * functions.
|
| + *
|
| + * More to the point, these functions make it obvious what libpng will be
|
| + * doing, whereas "expand" can (and does) mean any number of things.
|
| + *
|
| + * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
|
| + * to expand only the sample depth but not to expand the tRNS to alpha
|
| + * and its name was changed to png_set_expand_gray_1_2_4_to_8().
|
| + */
|
| +
|
| +/* Expand paletted images to RGB. */
|
| +void PNGAPI
|
| +png_set_palette_to_rgb(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_palette_to_rgb");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
| +}
|
| +
|
| +/* Expand grayscale images of less than 8-bit depth to 8 bits. */
|
| +void PNGAPI
|
| +png_set_expand_gray_1_2_4_to_8(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= PNG_EXPAND;
|
| +}
|
| +
|
| +/* Expand tRNS chunks to alpha channels. */
|
| +void PNGAPI
|
| +png_set_tRNS_to_alpha(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_tRNS_to_alpha");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
| +}
|
| +#endif /* READ_EXPAND */
|
| +
|
| +#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
| +/* Expand to 16-bit channels, expand the tRNS chunk too (because otherwise
|
| + * it may not work correctly.)
|
| + */
|
| +void PNGAPI
|
| +png_set_expand_16(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_expand_16");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + png_ptr->transformations |= (PNG_EXPAND_16 | PNG_EXPAND | PNG_EXPAND_tRNS);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
| +void PNGAPI
|
| +png_set_gray_to_rgb(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_set_gray_to_rgb");
|
| +
|
| + if (png_rtran_ok(png_ptr, 0) == 0)
|
| + return;
|
| +
|
| + /* Because rgb must be 8 bits or more: */
|
| + png_set_expand_gray_1_2_4_to_8(png_ptr);
|
| + png_ptr->transformations |= PNG_GRAY_TO_RGB;
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
| +void PNGFAPI
|
| +png_set_rgb_to_gray_fixed(png_structrp png_ptr, int error_action,
|
| + png_fixed_point red, png_fixed_point green)
|
| +{
|
| + png_debug(1, "in png_set_rgb_to_gray");
|
| +
|
| + /* Need the IHDR here because of the check on color_type below. */
|
| + /* TODO: fix this */
|
| + if (png_rtran_ok(png_ptr, 1) == 0)
|
| + return;
|
| +
|
| + switch (error_action)
|
| + {
|
| + case PNG_ERROR_ACTION_NONE:
|
| + png_ptr->transformations |= PNG_RGB_TO_GRAY;
|
| + break;
|
| +
|
| + case PNG_ERROR_ACTION_WARN:
|
| + png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
|
| + break;
|
| +
|
| + case PNG_ERROR_ACTION_ERROR:
|
| + png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
|
| + break;
|
| +
|
| + default:
|
| + png_error(png_ptr, "invalid error action to rgb_to_gray");
|
| + }
|
| +
|
| + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
| +#ifdef PNG_READ_EXPAND_SUPPORTED
|
| + png_ptr->transformations |= PNG_EXPAND;
|
| +#else
|
| + {
|
| + /* Make this an error in 1.6 because otherwise the application may assume
|
| + * that it just worked and get a memory overwrite.
|
| + */
|
| + png_error(png_ptr,
|
| + "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
|
| +
|
| + /* png_ptr->transformations &= ~PNG_RGB_TO_GRAY; */
|
| + }
|
| +#endif
|
| + {
|
| + if (red >= 0 && green >= 0 && red + green <= PNG_FP_1)
|
| + {
|
| + png_uint_16 red_int, green_int;
|
| +
|
| + /* NOTE: this calculation does not round, but this behavior is retained
|
| + * for consistency; the inaccuracy is very small. The code here always
|
| + * overwrites the coefficients, regardless of whether they have been
|
| + * defaulted or set already.
|
| + */
|
| + red_int = (png_uint_16)(((png_uint_32)red*32768)/100000);
|
| + green_int = (png_uint_16)(((png_uint_32)green*32768)/100000);
|
| +
|
| + png_ptr->rgb_to_gray_red_coeff = red_int;
|
| + png_ptr->rgb_to_gray_green_coeff = green_int;
|
| + png_ptr->rgb_to_gray_coefficients_set = 1;
|
| + }
|
| +
|
| + else
|
| + {
|
| + if (red >= 0 && green >= 0)
|
| + png_app_warning(png_ptr,
|
| + "ignoring out of range rgb_to_gray coefficients");
|
| +
|
| + /* Use the defaults, from the cHRM chunk if set, else the historical
|
| + * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See
|
| + * png_do_rgb_to_gray for more discussion of the values. In this case
|
| + * the coefficients are not marked as 'set' and are not overwritten if
|
| + * something has already provided a default.
|
| + */
|
| + if (png_ptr->rgb_to_gray_red_coeff == 0 &&
|
| + png_ptr->rgb_to_gray_green_coeff == 0)
|
| + {
|
| + png_ptr->rgb_to_gray_red_coeff = 6968;
|
| + png_ptr->rgb_to_gray_green_coeff = 23434;
|
| + /* png_ptr->rgb_to_gray_blue_coeff = 2366; */
|
| + }
|
| + }
|
| + }
|
| +}
|
| +
|
| +#ifdef PNG_FLOATING_POINT_SUPPORTED
|
| +/* Convert a RGB image to a grayscale of the same width. This allows us,
|
| + * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
|
| + */
|
| +
|
| +void PNGAPI
|
| +png_set_rgb_to_gray(png_structrp png_ptr, int error_action, double red,
|
| + double green)
|
| +{
|
| + png_set_rgb_to_gray_fixed(png_ptr, error_action,
|
| + png_fixed(png_ptr, red, "rgb to gray red coefficient"),
|
| + png_fixed(png_ptr, green, "rgb to gray green coefficient"));
|
| +}
|
| +#endif /* FLOATING POINT */
|
| +
|
| +#endif /* RGB_TO_GRAY */
|
| +
|
| +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
|
| + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
|
| +void PNGAPI
|
| +png_set_read_user_transform_fn(png_structrp png_ptr, png_user_transform_ptr
|
| + read_user_transform_fn)
|
| +{
|
| + png_debug(1, "in png_set_read_user_transform_fn");
|
| +
|
| +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
|
| + png_ptr->transformations |= PNG_USER_TRANSFORM;
|
| + png_ptr->read_user_transform_fn = read_user_transform_fn;
|
| +#endif
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_TRANSFORMS_SUPPORTED
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| +/* In the case of gamma transformations only do transformations on images where
|
| + * the [file] gamma and screen_gamma are not close reciprocals, otherwise it
|
| + * slows things down slightly, and also needlessly introduces small errors.
|
| + */
|
| +static int /* PRIVATE */
|
| +png_gamma_threshold(png_fixed_point screen_gamma, png_fixed_point file_gamma)
|
| +{
|
| + /* PNG_GAMMA_THRESHOLD is the threshold for performing gamma
|
| + * correction as a difference of the overall transform from 1.0
|
| + *
|
| + * We want to compare the threshold with s*f - 1, if we get
|
| + * overflow here it is because of wacky gamma values so we
|
| + * turn on processing anyway.
|
| + */
|
| + png_fixed_point gtest;
|
| + return !png_muldiv(>est, screen_gamma, file_gamma, PNG_FP_1) ||
|
| + png_gamma_significant(gtest);
|
| +}
|
| +#endif
|
| +
|
| +/* Initialize everything needed for the read. This includes modifying
|
| + * the palette.
|
| + */
|
| +
|
| +/* For the moment 'png_init_palette_transformations' and
|
| + * 'png_init_rgb_transformations' only do some flag canceling optimizations.
|
| + * The intent is that these two routines should have palette or rgb operations
|
| + * extracted from 'png_init_read_transformations'.
|
| + */
|
| +static void /* PRIVATE */
|
| +png_init_palette_transformations(png_structrp png_ptr)
|
| +{
|
| + /* Called to handle the (input) palette case. In png_do_read_transformations
|
| + * the first step is to expand the palette if requested, so this code must
|
| + * take care to only make changes that are invariant with respect to the
|
| + * palette expansion, or only do them if there is no expansion.
|
| + *
|
| + * STRIP_ALPHA has already been handled in the caller (by setting num_trans
|
| + * to 0.)
|
| + */
|
| + int input_has_alpha = 0;
|
| + int input_has_transparency = 0;
|
| +
|
| + if (png_ptr->num_trans > 0)
|
| + {
|
| + int i;
|
| +
|
| + /* Ignore if all the entries are opaque (unlikely!) */
|
| + for (i=0; i<png_ptr->num_trans; ++i)
|
| + {
|
| + if (png_ptr->trans_alpha[i] == 255)
|
| + continue;
|
| + else if (png_ptr->trans_alpha[i] == 0)
|
| + input_has_transparency = 1;
|
| + else
|
| + {
|
| + input_has_transparency = 1;
|
| + input_has_alpha = 1;
|
| + break;
|
| + }
|
| + }
|
| + }
|
| +
|
| + /* If no alpha we can optimize. */
|
| + if (input_has_alpha == 0)
|
| + {
|
| + /* Any alpha means background and associative alpha processing is
|
| + * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
|
| + * and ENCODE_ALPHA are irrelevant.
|
| + */
|
| + png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| +
|
| + if (input_has_transparency == 0)
|
| + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
|
| + }
|
| +
|
| +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
| + /* png_set_background handling - deals with the complexity of whether the
|
| + * background color is in the file format or the screen format in the case
|
| + * where an 'expand' will happen.
|
| + */
|
| +
|
| + /* The following code cannot be entered in the alpha pre-multiplication case
|
| + * because PNG_BACKGROUND_EXPAND is cancelled below.
|
| + */
|
| + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
|
| + (png_ptr->transformations & PNG_EXPAND) != 0)
|
| + {
|
| + {
|
| + png_ptr->background.red =
|
| + png_ptr->palette[png_ptr->background.index].red;
|
| + png_ptr->background.green =
|
| + png_ptr->palette[png_ptr->background.index].green;
|
| + png_ptr->background.blue =
|
| + png_ptr->palette[png_ptr->background.index].blue;
|
| +
|
| +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
|
| + {
|
| + if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
|
| + {
|
| + /* Invert the alpha channel (in tRNS) unless the pixels are
|
| + * going to be expanded, in which case leave it for later
|
| + */
|
| + int i, istop = png_ptr->num_trans;
|
| +
|
| + for (i=0; i<istop; i++)
|
| + png_ptr->trans_alpha[i] = (png_byte)(255 -
|
| + png_ptr->trans_alpha[i]);
|
| + }
|
| + }
|
| +#endif /* READ_INVERT_ALPHA */
|
| + }
|
| + } /* background expand and (therefore) no alpha association. */
|
| +#endif /* READ_EXPAND && READ_BACKGROUND */
|
| +}
|
| +
|
| +static void /* PRIVATE */
|
| +png_init_rgb_transformations(png_structrp png_ptr)
|
| +{
|
| + /* Added to libpng-1.5.4: check the color type to determine whether there
|
| + * is any alpha or transparency in the image and simply cancel the
|
| + * background and alpha mode stuff if there isn't.
|
| + */
|
| + int input_has_alpha = (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0;
|
| + int input_has_transparency = png_ptr->num_trans > 0;
|
| +
|
| + /* If no alpha we can optimize. */
|
| + if (input_has_alpha == 0)
|
| + {
|
| + /* Any alpha means background and associative alpha processing is
|
| + * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
|
| + * and ENCODE_ALPHA are irrelevant.
|
| + */
|
| +# ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
| + png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| +# endif
|
| +
|
| + if (input_has_transparency == 0)
|
| + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
|
| + }
|
| +
|
| +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
| + /* png_set_background handling - deals with the complexity of whether the
|
| + * background color is in the file format or the screen format in the case
|
| + * where an 'expand' will happen.
|
| + */
|
| +
|
| + /* The following code cannot be entered in the alpha pre-multiplication case
|
| + * because PNG_BACKGROUND_EXPAND is cancelled below.
|
| + */
|
| + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0 &&
|
| + (png_ptr->transformations & PNG_EXPAND) != 0 &&
|
| + (png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
|
| + /* i.e., GRAY or GRAY_ALPHA */
|
| + {
|
| + {
|
| + /* Expand background and tRNS chunks */
|
| + int gray = png_ptr->background.gray;
|
| + int trans_gray = png_ptr->trans_color.gray;
|
| +
|
| + switch (png_ptr->bit_depth)
|
| + {
|
| + case 1:
|
| + gray *= 0xff;
|
| + trans_gray *= 0xff;
|
| + break;
|
| +
|
| + case 2:
|
| + gray *= 0x55;
|
| + trans_gray *= 0x55;
|
| + break;
|
| +
|
| + case 4:
|
| + gray *= 0x11;
|
| + trans_gray *= 0x11;
|
| + break;
|
| +
|
| + default:
|
| +
|
| + case 8:
|
| + /* FALL THROUGH (Already 8 bits) */
|
| +
|
| + case 16:
|
| + /* Already a full 16 bits */
|
| + break;
|
| + }
|
| +
|
| + png_ptr->background.red = png_ptr->background.green =
|
| + png_ptr->background.blue = (png_uint_16)gray;
|
| +
|
| + if ((png_ptr->transformations & PNG_EXPAND_tRNS) == 0)
|
| + {
|
| + png_ptr->trans_color.red = png_ptr->trans_color.green =
|
| + png_ptr->trans_color.blue = (png_uint_16)trans_gray;
|
| + }
|
| + }
|
| + } /* background expand and (therefore) no alpha association. */
|
| +#endif /* READ_EXPAND && READ_BACKGROUND */
|
| +}
|
| +
|
| +void /* PRIVATE */
|
| +png_init_read_transformations(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_init_read_transformations");
|
| +
|
| + /* This internal function is called from png_read_start_row in pngrutil.c
|
| + * and it is called before the 'rowbytes' calculation is done, so the code
|
| + * in here can change or update the transformations flags.
|
| + *
|
| + * First do updates that do not depend on the details of the PNG image data
|
| + * being processed.
|
| + */
|
| +
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + /* Prior to 1.5.4 these tests were performed from png_set_gamma, 1.5.4 adds
|
| + * png_set_alpha_mode and this is another source for a default file gamma so
|
| + * the test needs to be performed later - here. In addition prior to 1.5.4
|
| + * the tests were repeated for the PALETTE color type here - this is no
|
| + * longer necessary (and doesn't seem to have been necessary before.)
|
| + */
|
| + {
|
| + /* The following temporary indicates if overall gamma correction is
|
| + * required.
|
| + */
|
| + int gamma_correction = 0;
|
| +
|
| + if (png_ptr->colorspace.gamma != 0) /* has been set */
|
| + {
|
| + if (png_ptr->screen_gamma != 0) /* screen set too */
|
| + gamma_correction = png_gamma_threshold(png_ptr->colorspace.gamma,
|
| + png_ptr->screen_gamma);
|
| +
|
| + else
|
| + /* Assume the output matches the input; a long time default behavior
|
| + * of libpng, although the standard has nothing to say about this.
|
| + */
|
| + png_ptr->screen_gamma = png_reciprocal(png_ptr->colorspace.gamma);
|
| + }
|
| +
|
| + else if (png_ptr->screen_gamma != 0)
|
| + /* The converse - assume the file matches the screen, note that this
|
| + * perhaps undesireable default can (from 1.5.4) be changed by calling
|
| + * png_set_alpha_mode (even if the alpha handling mode isn't required
|
| + * or isn't changed from the default.)
|
| + */
|
| + png_ptr->colorspace.gamma = png_reciprocal(png_ptr->screen_gamma);
|
| +
|
| + else /* neither are set */
|
| + /* Just in case the following prevents any processing - file and screen
|
| + * are both assumed to be linear and there is no way to introduce a
|
| + * third gamma value other than png_set_background with 'UNIQUE', and,
|
| + * prior to 1.5.4
|
| + */
|
| + png_ptr->screen_gamma = png_ptr->colorspace.gamma = PNG_FP_1;
|
| +
|
| + /* We have a gamma value now. */
|
| + png_ptr->colorspace.flags |= PNG_COLORSPACE_HAVE_GAMMA;
|
| +
|
| + /* Now turn the gamma transformation on or off as appropriate. Notice
|
| + * that PNG_GAMMA just refers to the file->screen correction. Alpha
|
| + * composition may independently cause gamma correction because it needs
|
| + * linear data (e.g. if the file has a gAMA chunk but the screen gamma
|
| + * hasn't been specified.) In any case this flag may get turned off in
|
| + * the code immediately below if the transform can be handled outside the
|
| + * row loop.
|
| + */
|
| + if (gamma_correction != 0)
|
| + png_ptr->transformations |= PNG_GAMMA;
|
| +
|
| + else
|
| + png_ptr->transformations &= ~PNG_GAMMA;
|
| + }
|
| +#endif
|
| +
|
| + /* Certain transformations have the effect of preventing other
|
| + * transformations that happen afterward in png_do_read_transformations;
|
| + * resolve the interdependencies here. From the code of
|
| + * png_do_read_transformations the order is:
|
| + *
|
| + * 1) PNG_EXPAND (including PNG_EXPAND_tRNS)
|
| + * 2) PNG_STRIP_ALPHA (if no compose)
|
| + * 3) PNG_RGB_TO_GRAY
|
| + * 4) PNG_GRAY_TO_RGB iff !PNG_BACKGROUND_IS_GRAY
|
| + * 5) PNG_COMPOSE
|
| + * 6) PNG_GAMMA
|
| + * 7) PNG_STRIP_ALPHA (if compose)
|
| + * 8) PNG_ENCODE_ALPHA
|
| + * 9) PNG_SCALE_16_TO_8
|
| + * 10) PNG_16_TO_8
|
| + * 11) PNG_QUANTIZE (converts to palette)
|
| + * 12) PNG_EXPAND_16
|
| + * 13) PNG_GRAY_TO_RGB iff PNG_BACKGROUND_IS_GRAY
|
| + * 14) PNG_INVERT_MONO
|
| + * 15) PNG_INVERT_ALPHA
|
| + * 16) PNG_SHIFT
|
| + * 17) PNG_PACK
|
| + * 18) PNG_BGR
|
| + * 19) PNG_PACKSWAP
|
| + * 20) PNG_FILLER (includes PNG_ADD_ALPHA)
|
| + * 21) PNG_SWAP_ALPHA
|
| + * 22) PNG_SWAP_BYTES
|
| + * 23) PNG_USER_TRANSFORM [must be last]
|
| + */
|
| +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
|
| + (png_ptr->transformations & PNG_COMPOSE) == 0)
|
| + {
|
| + /* Stripping the alpha channel happens immediately after the 'expand'
|
| + * transformations, before all other transformation, so it cancels out
|
| + * the alpha handling. It has the side effect negating the effect of
|
| + * PNG_EXPAND_tRNS too:
|
| + */
|
| + png_ptr->transformations &= ~(PNG_BACKGROUND_EXPAND | PNG_ENCODE_ALPHA |
|
| + PNG_EXPAND_tRNS);
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| +
|
| + /* Kill the tRNS chunk itself too. Prior to 1.5.4 this did not happen
|
| + * so transparency information would remain just so long as it wasn't
|
| + * expanded. This produces unexpected API changes if the set of things
|
| + * that do PNG_EXPAND_tRNS changes (perfectly possible given the
|
| + * documentation - which says ask for what you want, accept what you
|
| + * get.) This makes the behavior consistent from 1.5.4:
|
| + */
|
| + png_ptr->num_trans = 0;
|
| + }
|
| +#endif /* STRIP_ALPHA supported, no COMPOSE */
|
| +
|
| +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
| + /* If the screen gamma is about 1.0 then the OPTIMIZE_ALPHA and ENCODE_ALPHA
|
| + * settings will have no effect.
|
| + */
|
| + if (png_gamma_significant(png_ptr->screen_gamma) == 0)
|
| + {
|
| + png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
|
| + png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
|
| + }
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
| + /* Make sure the coefficients for the rgb to gray conversion are set
|
| + * appropriately.
|
| + */
|
| + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
| + png_colorspace_set_rgb_coefficients(png_ptr);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
| +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
| + /* Detect gray background and attempt to enable optimization for
|
| + * gray --> RGB case.
|
| + *
|
| + * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
|
| + * RGB_ALPHA (in which case need_expand is superfluous anyway), the
|
| + * background color might actually be gray yet not be flagged as such.
|
| + * This is not a problem for the current code, which uses
|
| + * PNG_BACKGROUND_IS_GRAY only to decide when to do the
|
| + * png_do_gray_to_rgb() transformation.
|
| + *
|
| + * TODO: this code needs to be revised to avoid the complexity and
|
| + * interdependencies. The color type of the background should be recorded in
|
| + * png_set_background, along with the bit depth, then the code has a record
|
| + * of exactly what color space the background is currently in.
|
| + */
|
| + if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) != 0)
|
| + {
|
| + /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if
|
| + * the file was grayscale the background value is gray.
|
| + */
|
| + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0)
|
| + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
| + }
|
| +
|
| + else if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
| + {
|
| + /* PNG_COMPOSE: png_set_background was called with need_expand false,
|
| + * so the color is in the color space of the output or png_set_alpha_mode
|
| + * was called and the color is black. Ignore RGB_TO_GRAY because that
|
| + * happens before GRAY_TO_RGB.
|
| + */
|
| + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
|
| + {
|
| + if (png_ptr->background.red == png_ptr->background.green &&
|
| + png_ptr->background.red == png_ptr->background.blue)
|
| + {
|
| + png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
| + png_ptr->background.gray = png_ptr->background.red;
|
| + }
|
| + }
|
| + }
|
| +#endif /* READ_EXPAND && READ_BACKGROUND */
|
| +#endif /* READ_GRAY_TO_RGB */
|
| +
|
| + /* For indexed PNG data (PNG_COLOR_TYPE_PALETTE) many of the transformations
|
| + * can be performed directly on the palette, and some (such as rgb to gray)
|
| + * can be optimized inside the palette. This is particularly true of the
|
| + * composite (background and alpha) stuff, which can be pretty much all done
|
| + * in the palette even if the result is expanded to RGB or gray afterward.
|
| + *
|
| + * NOTE: this is Not Yet Implemented, the code behaves as in 1.5.1 and
|
| + * earlier and the palette stuff is actually handled on the first row. This
|
| + * leads to the reported bug that the palette returned by png_get_PLTE is not
|
| + * updated.
|
| + */
|
| + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
| + png_init_palette_transformations(png_ptr);
|
| +
|
| + else
|
| + png_init_rgb_transformations(png_ptr);
|
| +
|
| +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
|
| + defined(PNG_READ_EXPAND_16_SUPPORTED)
|
| + if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
|
| + (png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
| + (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
|
| + png_ptr->bit_depth != 16)
|
| + {
|
| + /* TODO: fix this. Because the expand_16 operation is after the compose
|
| + * handling the background color must be 8, not 16, bits deep, but the
|
| + * application will supply a 16-bit value so reduce it here.
|
| + *
|
| + * The PNG_BACKGROUND_EXPAND code above does not expand to 16 bits at
|
| + * present, so that case is ok (until do_expand_16 is moved.)
|
| + *
|
| + * NOTE: this discards the low 16 bits of the user supplied background
|
| + * color, but until expand_16 works properly there is no choice!
|
| + */
|
| +# define CHOP(x) (x)=((png_uint_16)PNG_DIV257(x))
|
| + CHOP(png_ptr->background.red);
|
| + CHOP(png_ptr->background.green);
|
| + CHOP(png_ptr->background.blue);
|
| + CHOP(png_ptr->background.gray);
|
| +# undef CHOP
|
| + }
|
| +#endif /* READ_BACKGROUND && READ_EXPAND_16 */
|
| +
|
| +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
|
| + (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \
|
| + defined(PNG_READ_STRIP_16_TO_8_SUPPORTED))
|
| + if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) != 0 &&
|
| + (png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
| + (png_ptr->transformations & PNG_BACKGROUND_EXPAND) == 0 &&
|
| + png_ptr->bit_depth == 16)
|
| + {
|
| + /* On the other hand, if a 16-bit file is to be reduced to 8-bits per
|
| + * component this will also happen after PNG_COMPOSE and so the background
|
| + * color must be pre-expanded here.
|
| + *
|
| + * TODO: fix this too.
|
| + */
|
| + png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257);
|
| + png_ptr->background.green =
|
| + (png_uint_16)(png_ptr->background.green * 257);
|
| + png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257);
|
| + png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257);
|
| + }
|
| +#endif
|
| +
|
| + /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the
|
| + * background support (see the comments in scripts/pnglibconf.dfa), this
|
| + * allows pre-multiplication of the alpha channel to be implemented as
|
| + * compositing on black. This is probably sub-optimal and has been done in
|
| + * 1.5.4 betas simply to enable external critique and testing (i.e. to
|
| + * implement the new API quickly, without lots of internal changes.)
|
| + */
|
| +
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| +# ifdef PNG_READ_BACKGROUND_SUPPORTED
|
| + /* Includes ALPHA_MODE */
|
| + png_ptr->background_1 = png_ptr->background;
|
| +# endif
|
| +
|
| + /* This needs to change - in the palette image case a whole set of tables are
|
| + * built when it would be quicker to just calculate the correct value for
|
| + * each palette entry directly. Also, the test is too tricky - why check
|
| + * PNG_RGB_TO_GRAY if PNG_GAMMA is not set? The answer seems to be that
|
| + * PNG_GAMMA is cancelled even if the gamma is known? The test excludes the
|
| + * PNG_COMPOSE case, so apparently if there is no *overall* gamma correction
|
| + * the gamma tables will not be built even if composition is required on a
|
| + * gamma encoded value.
|
| + *
|
| + * In 1.5.4 this is addressed below by an additional check on the individual
|
| + * file gamma - if it is not 1.0 both RGB_TO_GRAY and COMPOSE need the
|
| + * tables.
|
| + */
|
| + if ((png_ptr->transformations & PNG_GAMMA) != 0 ||
|
| + ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0 &&
|
| + (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
|
| + png_gamma_significant(png_ptr->screen_gamma) != 0)) ||
|
| + ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
| + (png_gamma_significant(png_ptr->colorspace.gamma) != 0 ||
|
| + png_gamma_significant(png_ptr->screen_gamma) != 0
|
| +# ifdef PNG_READ_BACKGROUND_SUPPORTED
|
| + || (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_UNIQUE &&
|
| + png_gamma_significant(png_ptr->background_gamma) != 0)
|
| +# endif
|
| + )) || ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
|
| + png_gamma_significant(png_ptr->screen_gamma) != 0))
|
| + {
|
| + png_build_gamma_table(png_ptr, png_ptr->bit_depth);
|
| +
|
| +#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
| + {
|
| + /* Issue a warning about this combination: because RGB_TO_GRAY is
|
| + * optimized to do the gamma transform if present yet do_background has
|
| + * to do the same thing if both options are set a
|
| + * double-gamma-correction happens. This is true in all versions of
|
| + * libpng to date.
|
| + */
|
| + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
| + png_warning(png_ptr,
|
| + "libpng does not support gamma+background+rgb_to_gray");
|
| +
|
| + if ((png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) != 0)
|
| + {
|
| + /* We don't get to here unless there is a tRNS chunk with non-opaque
|
| + * entries - see the checking code at the start of this function.
|
| + */
|
| + png_color back, back_1;
|
| + png_colorp palette = png_ptr->palette;
|
| + int num_palette = png_ptr->num_palette;
|
| + int i;
|
| + if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
|
| + {
|
| +
|
| + back.red = png_ptr->gamma_table[png_ptr->background.red];
|
| + back.green = png_ptr->gamma_table[png_ptr->background.green];
|
| + back.blue = png_ptr->gamma_table[png_ptr->background.blue];
|
| +
|
| + back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
|
| + back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
|
| + back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
|
| + }
|
| + else
|
| + {
|
| + png_fixed_point g, gs;
|
| +
|
| + switch (png_ptr->background_gamma_type)
|
| + {
|
| + case PNG_BACKGROUND_GAMMA_SCREEN:
|
| + g = (png_ptr->screen_gamma);
|
| + gs = PNG_FP_1;
|
| + break;
|
| +
|
| + case PNG_BACKGROUND_GAMMA_FILE:
|
| + g = png_reciprocal(png_ptr->colorspace.gamma);
|
| + gs = png_reciprocal2(png_ptr->colorspace.gamma,
|
| + png_ptr->screen_gamma);
|
| + break;
|
| +
|
| + case PNG_BACKGROUND_GAMMA_UNIQUE:
|
| + g = png_reciprocal(png_ptr->background_gamma);
|
| + gs = png_reciprocal2(png_ptr->background_gamma,
|
| + png_ptr->screen_gamma);
|
| + break;
|
| + default:
|
| + g = PNG_FP_1; /* back_1 */
|
| + gs = PNG_FP_1; /* back */
|
| + break;
|
| + }
|
| +
|
| + if (png_gamma_significant(gs) != 0)
|
| + {
|
| + back.red = png_gamma_8bit_correct(png_ptr->background.red,
|
| + gs);
|
| + back.green = png_gamma_8bit_correct(png_ptr->background.green,
|
| + gs);
|
| + back.blue = png_gamma_8bit_correct(png_ptr->background.blue,
|
| + gs);
|
| + }
|
| +
|
| + else
|
| + {
|
| + back.red = (png_byte)png_ptr->background.red;
|
| + back.green = (png_byte)png_ptr->background.green;
|
| + back.blue = (png_byte)png_ptr->background.blue;
|
| + }
|
| +
|
| + if (png_gamma_significant(g) != 0)
|
| + {
|
| + back_1.red = png_gamma_8bit_correct(png_ptr->background.red,
|
| + g);
|
| + back_1.green = png_gamma_8bit_correct(
|
| + png_ptr->background.green, g);
|
| + back_1.blue = png_gamma_8bit_correct(png_ptr->background.blue,
|
| + g);
|
| + }
|
| +
|
| + else
|
| + {
|
| + back_1.red = (png_byte)png_ptr->background.red;
|
| + back_1.green = (png_byte)png_ptr->background.green;
|
| + back_1.blue = (png_byte)png_ptr->background.blue;
|
| + }
|
| + }
|
| +
|
| + for (i = 0; i < num_palette; i++)
|
| + {
|
| + if (i < (int)png_ptr->num_trans &&
|
| + png_ptr->trans_alpha[i] != 0xff)
|
| + {
|
| + if (png_ptr->trans_alpha[i] == 0)
|
| + {
|
| + palette[i] = back;
|
| + }
|
| + else /* if (png_ptr->trans_alpha[i] != 0xff) */
|
| + {
|
| + png_byte v, w;
|
| +
|
| + v = png_ptr->gamma_to_1[palette[i].red];
|
| + png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
|
| + palette[i].red = png_ptr->gamma_from_1[w];
|
| +
|
| + v = png_ptr->gamma_to_1[palette[i].green];
|
| + png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
|
| + palette[i].green = png_ptr->gamma_from_1[w];
|
| +
|
| + v = png_ptr->gamma_to_1[palette[i].blue];
|
| + png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
|
| + palette[i].blue = png_ptr->gamma_from_1[w];
|
| + }
|
| + }
|
| + else
|
| + {
|
| + palette[i].red = png_ptr->gamma_table[palette[i].red];
|
| + palette[i].green = png_ptr->gamma_table[palette[i].green];
|
| + palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
| + }
|
| + }
|
| +
|
| + /* Prevent the transformations being done again.
|
| + *
|
| + * NOTE: this is highly dubious; it removes the transformations in
|
| + * place. This seems inconsistent with the general treatment of the
|
| + * transformations elsewhere.
|
| + */
|
| + png_ptr->transformations &= ~(PNG_COMPOSE | PNG_GAMMA);
|
| + } /* color_type == PNG_COLOR_TYPE_PALETTE */
|
| +
|
| + /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
|
| + else /* color_type != PNG_COLOR_TYPE_PALETTE */
|
| + {
|
| + int gs_sig, g_sig;
|
| + png_fixed_point g = PNG_FP_1; /* Correction to linear */
|
| + png_fixed_point gs = PNG_FP_1; /* Correction to screen */
|
| +
|
| + switch (png_ptr->background_gamma_type)
|
| + {
|
| + case PNG_BACKGROUND_GAMMA_SCREEN:
|
| + g = png_ptr->screen_gamma;
|
| + /* gs = PNG_FP_1; */
|
| + break;
|
| +
|
| + case PNG_BACKGROUND_GAMMA_FILE:
|
| + g = png_reciprocal(png_ptr->colorspace.gamma);
|
| + gs = png_reciprocal2(png_ptr->colorspace.gamma,
|
| + png_ptr->screen_gamma);
|
| + break;
|
| +
|
| + case PNG_BACKGROUND_GAMMA_UNIQUE:
|
| + g = png_reciprocal(png_ptr->background_gamma);
|
| + gs = png_reciprocal2(png_ptr->background_gamma,
|
| + png_ptr->screen_gamma);
|
| + break;
|
| +
|
| + default:
|
| + png_error(png_ptr, "invalid background gamma type");
|
| + }
|
| +
|
| + g_sig = png_gamma_significant(g);
|
| + gs_sig = png_gamma_significant(gs);
|
| +
|
| + if (g_sig != 0)
|
| + png_ptr->background_1.gray = png_gamma_correct(png_ptr,
|
| + png_ptr->background.gray, g);
|
| +
|
| + if (gs_sig != 0)
|
| + png_ptr->background.gray = png_gamma_correct(png_ptr,
|
| + png_ptr->background.gray, gs);
|
| +
|
| + if ((png_ptr->background.red != png_ptr->background.green) ||
|
| + (png_ptr->background.red != png_ptr->background.blue) ||
|
| + (png_ptr->background.red != png_ptr->background.gray))
|
| + {
|
| + /* RGB or RGBA with color background */
|
| + if (g_sig != 0)
|
| + {
|
| + png_ptr->background_1.red = png_gamma_correct(png_ptr,
|
| + png_ptr->background.red, g);
|
| +
|
| + png_ptr->background_1.green = png_gamma_correct(png_ptr,
|
| + png_ptr->background.green, g);
|
| +
|
| + png_ptr->background_1.blue = png_gamma_correct(png_ptr,
|
| + png_ptr->background.blue, g);
|
| + }
|
| +
|
| + if (gs_sig != 0)
|
| + {
|
| + png_ptr->background.red = png_gamma_correct(png_ptr,
|
| + png_ptr->background.red, gs);
|
| +
|
| + png_ptr->background.green = png_gamma_correct(png_ptr,
|
| + png_ptr->background.green, gs);
|
| +
|
| + png_ptr->background.blue = png_gamma_correct(png_ptr,
|
| + png_ptr->background.blue, gs);
|
| + }
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
|
| + png_ptr->background_1.red = png_ptr->background_1.green
|
| + = png_ptr->background_1.blue = png_ptr->background_1.gray;
|
| +
|
| + png_ptr->background.red = png_ptr->background.green
|
| + = png_ptr->background.blue = png_ptr->background.gray;
|
| + }
|
| +
|
| + /* The background is now in screen gamma: */
|
| + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN;
|
| + } /* color_type != PNG_COLOR_TYPE_PALETTE */
|
| + }/* png_ptr->transformations & PNG_BACKGROUND */
|
| +
|
| + else
|
| + /* Transformation does not include PNG_BACKGROUND */
|
| +#endif /* READ_BACKGROUND */
|
| + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE
|
| +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
| + /* RGB_TO_GRAY needs to have non-gamma-corrected values! */
|
| + && ((png_ptr->transformations & PNG_EXPAND) == 0 ||
|
| + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0)
|
| +#endif
|
| + )
|
| + {
|
| + png_colorp palette = png_ptr->palette;
|
| + int num_palette = png_ptr->num_palette;
|
| + int i;
|
| +
|
| + /* NOTE: there are other transformations that should probably be in
|
| + * here too.
|
| + */
|
| + for (i = 0; i < num_palette; i++)
|
| + {
|
| + palette[i].red = png_ptr->gamma_table[palette[i].red];
|
| + palette[i].green = png_ptr->gamma_table[palette[i].green];
|
| + palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
| + }
|
| +
|
| + /* Done the gamma correction. */
|
| + png_ptr->transformations &= ~PNG_GAMMA;
|
| + } /* color_type == PALETTE && !PNG_BACKGROUND transformation */
|
| + }
|
| +#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
| + else
|
| +#endif
|
| +#endif /* READ_GAMMA */
|
| +
|
| +#ifdef PNG_READ_BACKGROUND_SUPPORTED
|
| + /* No GAMMA transformation (see the hanging else 4 lines above) */
|
| + if ((png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
| + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
|
| + {
|
| + int i;
|
| + int istop = (int)png_ptr->num_trans;
|
| + png_color back;
|
| + png_colorp palette = png_ptr->palette;
|
| +
|
| + back.red = (png_byte)png_ptr->background.red;
|
| + back.green = (png_byte)png_ptr->background.green;
|
| + back.blue = (png_byte)png_ptr->background.blue;
|
| +
|
| + for (i = 0; i < istop; i++)
|
| + {
|
| + if (png_ptr->trans_alpha[i] == 0)
|
| + {
|
| + palette[i] = back;
|
| + }
|
| +
|
| + else if (png_ptr->trans_alpha[i] != 0xff)
|
| + {
|
| + /* The png_composite() macro is defined in png.h */
|
| + png_composite(palette[i].red, palette[i].red,
|
| + png_ptr->trans_alpha[i], back.red);
|
| +
|
| + png_composite(palette[i].green, palette[i].green,
|
| + png_ptr->trans_alpha[i], back.green);
|
| +
|
| + png_composite(palette[i].blue, palette[i].blue,
|
| + png_ptr->trans_alpha[i], back.blue);
|
| + }
|
| + }
|
| +
|
| + png_ptr->transformations &= ~PNG_COMPOSE;
|
| + }
|
| +#endif /* READ_BACKGROUND */
|
| +
|
| +#ifdef PNG_READ_SHIFT_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_SHIFT) != 0 &&
|
| + (png_ptr->transformations & PNG_EXPAND) == 0 &&
|
| + (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
|
| + {
|
| + int i;
|
| + int istop = png_ptr->num_palette;
|
| + int shift = 8 - png_ptr->sig_bit.red;
|
| +
|
| + png_ptr->transformations &= ~PNG_SHIFT;
|
| +
|
| + /* significant bits can be in the range 1 to 7 for a meaninful result, if
|
| + * the number of significant bits is 0 then no shift is done (this is an
|
| + * error condition which is silently ignored.)
|
| + */
|
| + if (shift > 0 && shift < 8)
|
| + for (i=0; i<istop; ++i)
|
| + {
|
| + int component = png_ptr->palette[i].red;
|
| +
|
| + component >>= shift;
|
| + png_ptr->palette[i].red = (png_byte)component;
|
| + }
|
| +
|
| + shift = 8 - png_ptr->sig_bit.green;
|
| + if (shift > 0 && shift < 8)
|
| + for (i=0; i<istop; ++i)
|
| + {
|
| + int component = png_ptr->palette[i].green;
|
| +
|
| + component >>= shift;
|
| + png_ptr->palette[i].green = (png_byte)component;
|
| + }
|
| +
|
| + shift = 8 - png_ptr->sig_bit.blue;
|
| + if (shift > 0 && shift < 8)
|
| + for (i=0; i<istop; ++i)
|
| + {
|
| + int component = png_ptr->palette[i].blue;
|
| +
|
| + component >>= shift;
|
| + png_ptr->palette[i].blue = (png_byte)component;
|
| + }
|
| + }
|
| +#endif /* READ_SHIFT */
|
| +}
|
| +
|
| +/* Modify the info structure to reflect the transformations. The
|
| + * info should be updated so a PNG file could be written with it,
|
| + * assuming the transformations result in valid PNG data.
|
| + */
|
| +void /* PRIVATE */
|
| +png_read_transform_info(png_structrp png_ptr, png_inforp info_ptr)
|
| +{
|
| + png_debug(1, "in png_read_transform_info");
|
| +
|
| +#ifdef PNG_READ_EXPAND_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_EXPAND) != 0)
|
| + {
|
| + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + /* This check must match what actually happens in
|
| + * png_do_expand_palette; if it ever checks the tRNS chunk to see if
|
| + * it is all opaque we must do the same (at present it does not.)
|
| + */
|
| + if (png_ptr->num_trans > 0)
|
| + info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
| +
|
| + else
|
| + info_ptr->color_type = PNG_COLOR_TYPE_RGB;
|
| +
|
| + info_ptr->bit_depth = 8;
|
| + info_ptr->num_trans = 0;
|
| +
|
| + if (png_ptr->palette == NULL)
|
| + png_error (png_ptr, "Palette is NULL in indexed image");
|
| + }
|
| + else
|
| + {
|
| + if (png_ptr->num_trans != 0)
|
| + {
|
| + if ((png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
|
| + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
|
| + }
|
| + if (info_ptr->bit_depth < 8)
|
| + info_ptr->bit_depth = 8;
|
| +
|
| + info_ptr->num_trans = 0;
|
| + }
|
| + }
|
| +#endif
|
| +
|
| +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
| + defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
| + /* The following is almost certainly wrong unless the background value is in
|
| + * the screen space!
|
| + */
|
| + if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
| + info_ptr->background = png_ptr->background;
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + /* The following used to be conditional on PNG_GAMMA (prior to 1.5.4),
|
| + * however it seems that the code in png_init_read_transformations, which has
|
| + * been called before this from png_read_update_info->png_read_start_row
|
| + * sometimes does the gamma transform and cancels the flag.
|
| + *
|
| + * TODO: this looks wrong; the info_ptr should end up with a gamma equal to
|
| + * the screen_gamma value. The following probably results in weirdness if
|
| + * the info_ptr is used by the app after the rows have been read.
|
| + */
|
| + info_ptr->colorspace.gamma = png_ptr->colorspace.gamma;
|
| +#endif
|
| +
|
| + if (info_ptr->bit_depth == 16)
|
| + {
|
| +# ifdef PNG_READ_16BIT_SUPPORTED
|
| +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
|
| + info_ptr->bit_depth = 8;
|
| +# endif
|
| +
|
| +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_16_TO_8) != 0)
|
| + info_ptr->bit_depth = 8;
|
| +# endif
|
| +
|
| +# else
|
| + /* No 16-bit support: force chopping 16-bit input down to 8, in this case
|
| + * the app program can chose if both APIs are available by setting the
|
| + * correct scaling to use.
|
| + */
|
| +# ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
| + /* For compatibility with previous versions use the strip method by
|
| + * default. This code works because if PNG_SCALE_16_TO_8 is already
|
| + * set the code below will do that in preference to the chop.
|
| + */
|
| + png_ptr->transformations |= PNG_16_TO_8;
|
| + info_ptr->bit_depth = 8;
|
| +# else
|
| +
|
| +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
| + png_ptr->transformations |= PNG_SCALE_16_TO_8;
|
| + info_ptr->bit_depth = 8;
|
| +# else
|
| +
|
| + CONFIGURATION ERROR: you must enable at least one 16 to 8 method
|
| +# endif
|
| +# endif
|
| +#endif /* !READ_16BIT */
|
| + }
|
| +
|
| +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0)
|
| + info_ptr->color_type = (png_byte)(info_ptr->color_type |
|
| + PNG_COLOR_MASK_COLOR);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
| + info_ptr->color_type = (png_byte)(info_ptr->color_type &
|
| + ~PNG_COLOR_MASK_COLOR);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
|
| + {
|
| + if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
|
| + (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
|
| + png_ptr->palette_lookup != 0 && info_ptr->bit_depth == 8)
|
| + {
|
| + info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
|
| + }
|
| + }
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_EXPAND_16) != 0 &&
|
| + info_ptr->bit_depth == 8 &&
|
| + info_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + info_ptr->bit_depth = 16;
|
| + }
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_PACK_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_PACK) != 0 &&
|
| + (info_ptr->bit_depth < 8))
|
| + info_ptr->bit_depth = 8;
|
| +#endif
|
| +
|
| + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
| + info_ptr->channels = 1;
|
| +
|
| + else if ((info_ptr->color_type & PNG_COLOR_MASK_COLOR) != 0)
|
| + info_ptr->channels = 3;
|
| +
|
| + else
|
| + info_ptr->channels = 1;
|
| +
|
| +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0)
|
| + {
|
| + info_ptr->color_type = (png_byte)(info_ptr->color_type &
|
| + ~PNG_COLOR_MASK_ALPHA);
|
| + info_ptr->num_trans = 0;
|
| + }
|
| +#endif
|
| +
|
| + if ((info_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
| + info_ptr->channels++;
|
| +
|
| +#ifdef PNG_READ_FILLER_SUPPORTED
|
| + /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
|
| + if ((png_ptr->transformations & PNG_FILLER) != 0 &&
|
| + (info_ptr->color_type == PNG_COLOR_TYPE_RGB ||
|
| + info_ptr->color_type == PNG_COLOR_TYPE_GRAY))
|
| + {
|
| + info_ptr->channels++;
|
| + /* If adding a true alpha channel not just filler */
|
| + if ((png_ptr->transformations & PNG_ADD_ALPHA) != 0)
|
| + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
|
| + }
|
| +#endif
|
| +
|
| +#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
|
| +defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
|
| + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
|
| + {
|
| + if (png_ptr->user_transform_depth != 0)
|
| + info_ptr->bit_depth = png_ptr->user_transform_depth;
|
| +
|
| + if (png_ptr->user_transform_channels != 0)
|
| + info_ptr->channels = png_ptr->user_transform_channels;
|
| + }
|
| +#endif
|
| +
|
| + info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
|
| + info_ptr->bit_depth);
|
| +
|
| + info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
|
| +
|
| + /* Adding in 1.5.4: cache the above value in png_struct so that we can later
|
| + * check in png_rowbytes that the user buffer won't get overwritten. Note
|
| + * that the field is not always set - if png_read_update_info isn't called
|
| + * the application has to either not do any transforms or get the calculation
|
| + * right itself.
|
| + */
|
| + png_ptr->info_rowbytes = info_ptr->rowbytes;
|
| +
|
| +#ifndef PNG_READ_EXPAND_SUPPORTED
|
| + if (png_ptr != NULL)
|
| + return;
|
| +#endif
|
| +}
|
| +
|
| +#ifdef PNG_READ_PACK_SUPPORTED
|
| +/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
|
| + * without changing the actual values. Thus, if you had a row with
|
| + * a bit depth of 1, you would end up with bytes that only contained
|
| + * the numbers 0 or 1. If you would rather they contain 0 and 255, use
|
| + * png_do_shift() after this.
|
| + */
|
| +static void
|
| +png_do_unpack(png_row_infop row_info, png_bytep row)
|
| +{
|
| + png_debug(1, "in png_do_unpack");
|
| +
|
| + if (row_info->bit_depth < 8)
|
| + {
|
| + png_uint_32 i;
|
| + png_uint_32 row_width=row_info->width;
|
| +
|
| + switch (row_info->bit_depth)
|
| + {
|
| + case 1:
|
| + {
|
| + png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
|
| + png_bytep dp = row + (png_size_t)row_width - 1;
|
| + png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *dp = (png_byte)((*sp >> shift) & 0x01);
|
| +
|
| + if (shift == 7)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift++;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 2:
|
| + {
|
| +
|
| + png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
|
| + png_bytep dp = row + (png_size_t)row_width - 1;
|
| + png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *dp = (png_byte)((*sp >> shift) & 0x03);
|
| +
|
| + if (shift == 6)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift += 2;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 4:
|
| + {
|
| + png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
|
| + png_bytep dp = row + (png_size_t)row_width - 1;
|
| + png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *dp = (png_byte)((*sp >> shift) & 0x0f);
|
| +
|
| + if (shift == 4)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift = 4;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + default:
|
| + break;
|
| + }
|
| + row_info->bit_depth = 8;
|
| + row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
| + row_info->rowbytes = row_width * row_info->channels;
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_SHIFT_SUPPORTED
|
| +/* Reverse the effects of png_do_shift. This routine merely shifts the
|
| + * pixels back to their significant bits values. Thus, if you have
|
| + * a row of bit depth 8, but only 5 are significant, this will shift
|
| + * the values back to 0 through 31.
|
| + */
|
| +static void
|
| +png_do_unshift(png_row_infop row_info, png_bytep row,
|
| + png_const_color_8p sig_bits)
|
| +{
|
| + int color_type;
|
| +
|
| + png_debug(1, "in png_do_unshift");
|
| +
|
| + /* The palette case has already been handled in the _init routine. */
|
| + color_type = row_info->color_type;
|
| +
|
| + if (color_type != PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + int shift[4];
|
| + int channels = 0;
|
| + int bit_depth = row_info->bit_depth;
|
| +
|
| + if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
|
| + {
|
| + shift[channels++] = bit_depth - sig_bits->red;
|
| + shift[channels++] = bit_depth - sig_bits->green;
|
| + shift[channels++] = bit_depth - sig_bits->blue;
|
| + }
|
| +
|
| + else
|
| + {
|
| + shift[channels++] = bit_depth - sig_bits->gray;
|
| + }
|
| +
|
| + if ((color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
| + {
|
| + shift[channels++] = bit_depth - sig_bits->alpha;
|
| + }
|
| +
|
| + {
|
| + int c, have_shift;
|
| +
|
| + for (c = have_shift = 0; c < channels; ++c)
|
| + {
|
| + /* A shift of more than the bit depth is an error condition but it
|
| + * gets ignored here.
|
| + */
|
| + if (shift[c] <= 0 || shift[c] >= bit_depth)
|
| + shift[c] = 0;
|
| +
|
| + else
|
| + have_shift = 1;
|
| + }
|
| +
|
| + if (have_shift == 0)
|
| + return;
|
| + }
|
| +
|
| + switch (bit_depth)
|
| + {
|
| + default:
|
| + /* Must be 1bpp gray: should not be here! */
|
| + /* NOTREACHED */
|
| + break;
|
| +
|
| + case 2:
|
| + /* Must be 2bpp gray */
|
| + /* assert(channels == 1 && shift[0] == 1) */
|
| + {
|
| + png_bytep bp = row;
|
| + png_bytep bp_end = bp + row_info->rowbytes;
|
| +
|
| + while (bp < bp_end)
|
| + {
|
| + int b = (*bp >> 1) & 0x55;
|
| + *bp++ = (png_byte)b;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 4:
|
| + /* Must be 4bpp gray */
|
| + /* assert(channels == 1) */
|
| + {
|
| + png_bytep bp = row;
|
| + png_bytep bp_end = bp + row_info->rowbytes;
|
| + int gray_shift = shift[0];
|
| + int mask = 0xf >> gray_shift;
|
| +
|
| + mask |= mask << 4;
|
| +
|
| + while (bp < bp_end)
|
| + {
|
| + int b = (*bp >> gray_shift) & mask;
|
| + *bp++ = (png_byte)b;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 8:
|
| + /* Single byte components, G, GA, RGB, RGBA */
|
| + {
|
| + png_bytep bp = row;
|
| + png_bytep bp_end = bp + row_info->rowbytes;
|
| + int channel = 0;
|
| +
|
| + while (bp < bp_end)
|
| + {
|
| + int b = *bp >> shift[channel];
|
| + if (++channel >= channels)
|
| + channel = 0;
|
| + *bp++ = (png_byte)b;
|
| + }
|
| + break;
|
| + }
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + case 16:
|
| + /* Double byte components, G, GA, RGB, RGBA */
|
| + {
|
| + png_bytep bp = row;
|
| + png_bytep bp_end = bp + row_info->rowbytes;
|
| + int channel = 0;
|
| +
|
| + while (bp < bp_end)
|
| + {
|
| + int value = (bp[0] << 8) + bp[1];
|
| +
|
| + value >>= shift[channel];
|
| + if (++channel >= channels)
|
| + channel = 0;
|
| + *bp++ = (png_byte)(value >> 8);
|
| + *bp++ = (png_byte)value;
|
| + }
|
| + break;
|
| + }
|
| +#endif
|
| + }
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
| +/* Scale rows of bit depth 16 down to 8 accurately */
|
| +static void
|
| +png_do_scale_16_to_8(png_row_infop row_info, png_bytep row)
|
| +{
|
| + png_debug(1, "in png_do_scale_16_to_8");
|
| +
|
| + if (row_info->bit_depth == 16)
|
| + {
|
| + png_bytep sp = row; /* source */
|
| + png_bytep dp = row; /* destination */
|
| + png_bytep ep = sp + row_info->rowbytes; /* end+1 */
|
| +
|
| + while (sp < ep)
|
| + {
|
| + /* The input is an array of 16-bit components, these must be scaled to
|
| + * 8 bits each. For a 16-bit value V the required value (from the PNG
|
| + * specification) is:
|
| + *
|
| + * (V * 255) / 65535
|
| + *
|
| + * This reduces to round(V / 257), or floor((V + 128.5)/257)
|
| + *
|
| + * Represent V as the two byte value vhi.vlo. Make a guess that the
|
| + * result is the top byte of V, vhi, then the correction to this value
|
| + * is:
|
| + *
|
| + * error = floor(((V-vhi.vhi) + 128.5) / 257)
|
| + * = floor(((vlo-vhi) + 128.5) / 257)
|
| + *
|
| + * This can be approximated using integer arithmetic (and a signed
|
| + * shift):
|
| + *
|
| + * error = (vlo-vhi+128) >> 8;
|
| + *
|
| + * The approximate differs from the exact answer only when (vlo-vhi) is
|
| + * 128; it then gives a correction of +1 when the exact correction is
|
| + * 0. This gives 128 errors. The exact answer (correct for all 16-bit
|
| + * input values) is:
|
| + *
|
| + * error = (vlo-vhi+128)*65535 >> 24;
|
| + *
|
| + * An alternative arithmetic calculation which also gives no errors is:
|
| + *
|
| + * (V * 255 + 32895) >> 16
|
| + */
|
| +
|
| + png_int_32 tmp = *sp++; /* must be signed! */
|
| + tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
|
| + *dp++ = (png_byte)tmp;
|
| + }
|
| +
|
| + row_info->bit_depth = 8;
|
| + row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
| + row_info->rowbytes = row_info->width * row_info->channels;
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
| +static void
|
| +/* Simply discard the low byte. This was the default behavior prior
|
| + * to libpng-1.5.4.
|
| + */
|
| +png_do_chop(png_row_infop row_info, png_bytep row)
|
| +{
|
| + png_debug(1, "in png_do_chop");
|
| +
|
| + if (row_info->bit_depth == 16)
|
| + {
|
| + png_bytep sp = row; /* source */
|
| + png_bytep dp = row; /* destination */
|
| + png_bytep ep = sp + row_info->rowbytes; /* end+1 */
|
| +
|
| + while (sp < ep)
|
| + {
|
| + *dp++ = *sp;
|
| + sp += 2; /* skip low byte */
|
| + }
|
| +
|
| + row_info->bit_depth = 8;
|
| + row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
| + row_info->rowbytes = row_info->width * row_info->channels;
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
|
| +static void
|
| +png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
|
| +{
|
| + png_debug(1, "in png_do_read_swap_alpha");
|
| +
|
| + {
|
| + png_uint_32 row_width = row_info->width;
|
| + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
| + {
|
| + /* This converts from RGBA to ARGB */
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_byte save;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + save = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = save;
|
| + }
|
| + }
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + /* This converts from RRGGBBAA to AARRGGBB */
|
| + else
|
| + {
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_byte save[2];
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + save[0] = *(--sp);
|
| + save[1] = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = save[0];
|
| + *(--dp) = save[1];
|
| + }
|
| + }
|
| +#endif
|
| + }
|
| +
|
| + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
| + {
|
| + /* This converts from GA to AG */
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_byte save;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + save = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = save;
|
| + }
|
| + }
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + /* This converts from GGAA to AAGG */
|
| + else
|
| + {
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_byte save[2];
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + save[0] = *(--sp);
|
| + save[1] = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = save[0];
|
| + *(--dp) = save[1];
|
| + }
|
| + }
|
| +#endif
|
| + }
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
|
| +static void
|
| +png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
|
| +{
|
| + png_uint_32 row_width;
|
| + png_debug(1, "in png_do_read_invert_alpha");
|
| +
|
| + row_width = row_info->width;
|
| + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + /* This inverts the alpha channel in RGBA */
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = (png_byte)(255 - *(--sp));
|
| +
|
| +/* This does nothing:
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + We can replace it with:
|
| +*/
|
| + sp-=3;
|
| + dp=sp;
|
| + }
|
| + }
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + /* This inverts the alpha channel in RRGGBBAA */
|
| + else
|
| + {
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = (png_byte)(255 - *(--sp));
|
| + *(--dp) = (png_byte)(255 - *(--sp));
|
| +
|
| +/* This does nothing:
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + We can replace it with:
|
| +*/
|
| + sp-=6;
|
| + dp=sp;
|
| + }
|
| + }
|
| +#endif
|
| + }
|
| + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + /* This inverts the alpha channel in GA */
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = (png_byte)(255 - *(--sp));
|
| + *(--dp) = *(--sp);
|
| + }
|
| + }
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + else
|
| + {
|
| + /* This inverts the alpha channel in GGAA */
|
| + png_bytep sp = row + row_info->rowbytes;
|
| + png_bytep dp = sp;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = (png_byte)(255 - *(--sp));
|
| + *(--dp) = (png_byte)(255 - *(--sp));
|
| +/*
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| +*/
|
| + sp-=2;
|
| + dp=sp;
|
| + }
|
| + }
|
| +#endif
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_FILLER_SUPPORTED
|
| +/* Add filler channel if we have RGB color */
|
| +static void
|
| +png_do_read_filler(png_row_infop row_info, png_bytep row,
|
| + png_uint_32 filler, png_uint_32 flags)
|
| +{
|
| + png_uint_32 i;
|
| + png_uint_32 row_width = row_info->width;
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + png_byte hi_filler = (png_byte)(filler>>8);
|
| +#endif
|
| + png_byte lo_filler = (png_byte)filler;
|
| +
|
| + png_debug(1, "in png_do_read_filler");
|
| +
|
| + if (
|
| + row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
| + {
|
| + /* This changes the data from G to GX */
|
| + png_bytep sp = row + (png_size_t)row_width;
|
| + png_bytep dp = sp + (png_size_t)row_width;
|
| + for (i = 1; i < row_width; i++)
|
| + {
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = *(--sp);
|
| + }
|
| + *(--dp) = lo_filler;
|
| + row_info->channels = 2;
|
| + row_info->pixel_depth = 16;
|
| + row_info->rowbytes = row_width * 2;
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* This changes the data from G to XG */
|
| + png_bytep sp = row + (png_size_t)row_width;
|
| + png_bytep dp = sp + (png_size_t)row_width;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = lo_filler;
|
| + }
|
| + row_info->channels = 2;
|
| + row_info->pixel_depth = 16;
|
| + row_info->rowbytes = row_width * 2;
|
| + }
|
| + }
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + else if (row_info->bit_depth == 16)
|
| + {
|
| + if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
| + {
|
| + /* This changes the data from GG to GGXX */
|
| + png_bytep sp = row + (png_size_t)row_width * 2;
|
| + png_bytep dp = sp + (png_size_t)row_width * 2;
|
| + for (i = 1; i < row_width; i++)
|
| + {
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = hi_filler;
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + }
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = hi_filler;
|
| + row_info->channels = 2;
|
| + row_info->pixel_depth = 32;
|
| + row_info->rowbytes = row_width * 4;
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* This changes the data from GG to XXGG */
|
| + png_bytep sp = row + (png_size_t)row_width * 2;
|
| + png_bytep dp = sp + (png_size_t)row_width * 2;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = hi_filler;
|
| + }
|
| + row_info->channels = 2;
|
| + row_info->pixel_depth = 32;
|
| + row_info->rowbytes = row_width * 4;
|
| + }
|
| + }
|
| +#endif
|
| + } /* COLOR_TYPE == GRAY */
|
| + else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
| + {
|
| + /* This changes the data from RGB to RGBX */
|
| + png_bytep sp = row + (png_size_t)row_width * 3;
|
| + png_bytep dp = sp + (png_size_t)row_width;
|
| + for (i = 1; i < row_width; i++)
|
| + {
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + }
|
| + *(--dp) = lo_filler;
|
| + row_info->channels = 4;
|
| + row_info->pixel_depth = 32;
|
| + row_info->rowbytes = row_width * 4;
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* This changes the data from RGB to XRGB */
|
| + png_bytep sp = row + (png_size_t)row_width * 3;
|
| + png_bytep dp = sp + (png_size_t)row_width;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = lo_filler;
|
| + }
|
| + row_info->channels = 4;
|
| + row_info->pixel_depth = 32;
|
| + row_info->rowbytes = row_width * 4;
|
| + }
|
| + }
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| + else if (row_info->bit_depth == 16)
|
| + {
|
| + if ((flags & PNG_FLAG_FILLER_AFTER) != 0)
|
| + {
|
| + /* This changes the data from RRGGBB to RRGGBBXX */
|
| + png_bytep sp = row + (png_size_t)row_width * 6;
|
| + png_bytep dp = sp + (png_size_t)row_width * 2;
|
| + for (i = 1; i < row_width; i++)
|
| + {
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = hi_filler;
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + }
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = hi_filler;
|
| + row_info->channels = 4;
|
| + row_info->pixel_depth = 64;
|
| + row_info->rowbytes = row_width * 8;
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* This changes the data from RRGGBB to XXRRGGBB */
|
| + png_bytep sp = row + (png_size_t)row_width * 6;
|
| + png_bytep dp = sp + (png_size_t)row_width * 2;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = *(--sp);
|
| + *(--dp) = lo_filler;
|
| + *(--dp) = hi_filler;
|
| + }
|
| +
|
| + row_info->channels = 4;
|
| + row_info->pixel_depth = 64;
|
| + row_info->rowbytes = row_width * 8;
|
| + }
|
| + }
|
| +#endif
|
| + } /* COLOR_TYPE == RGB */
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
| +/* Expand grayscale files to RGB, with or without alpha */
|
| +static void
|
| +png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
|
| +{
|
| + png_uint_32 i;
|
| + png_uint_32 row_width = row_info->width;
|
| +
|
| + png_debug(1, "in png_do_gray_to_rgb");
|
| +
|
| + if (row_info->bit_depth >= 8 &&
|
| + (row_info->color_type & PNG_COLOR_MASK_COLOR) == 0)
|
| + {
|
| + if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + /* This changes G to RGB */
|
| + png_bytep sp = row + (png_size_t)row_width - 1;
|
| + png_bytep dp = sp + (png_size_t)row_width * 2;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(dp--) = *sp;
|
| + *(dp--) = *sp;
|
| + *(dp--) = *(sp--);
|
| + }
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* This changes GG to RRGGBB */
|
| + png_bytep sp = row + (png_size_t)row_width * 2 - 1;
|
| + png_bytep dp = sp + (png_size_t)row_width * 4;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(dp--) = *sp;
|
| + *(dp--) = *(sp - 1);
|
| + *(dp--) = *sp;
|
| + *(dp--) = *(sp - 1);
|
| + *(dp--) = *(sp--);
|
| + *(dp--) = *(sp--);
|
| + }
|
| + }
|
| + }
|
| +
|
| + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + /* This changes GA to RGBA */
|
| + png_bytep sp = row + (png_size_t)row_width * 2 - 1;
|
| + png_bytep dp = sp + (png_size_t)row_width * 2;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(dp--) = *(sp--);
|
| + *(dp--) = *sp;
|
| + *(dp--) = *sp;
|
| + *(dp--) = *(sp--);
|
| + }
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* This changes GGAA to RRGGBBAA */
|
| + png_bytep sp = row + (png_size_t)row_width * 4 - 1;
|
| + png_bytep dp = sp + (png_size_t)row_width * 4;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *(dp--) = *(sp--);
|
| + *(dp--) = *(sp--);
|
| + *(dp--) = *sp;
|
| + *(dp--) = *(sp - 1);
|
| + *(dp--) = *sp;
|
| + *(dp--) = *(sp - 1);
|
| + *(dp--) = *(sp--);
|
| + *(dp--) = *(sp--);
|
| + }
|
| + }
|
| + }
|
| + row_info->channels = (png_byte)(row_info->channels + 2);
|
| + row_info->color_type |= PNG_COLOR_MASK_COLOR;
|
| + row_info->pixel_depth = (png_byte)(row_info->channels *
|
| + row_info->bit_depth);
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
| +/* Reduce RGB files to grayscale, with or without alpha
|
| + * using the equation given in Poynton's ColorFAQ of 1998-01-04 at
|
| + * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but
|
| + * versions dated 1998 through November 2002 have been archived at
|
| + * http://web.archive.org/web/20000816232553/http://www.inforamp.net/
|
| + * ~poynton/notes/colour_and_gamma/ColorFAQ.txt )
|
| + * Charles Poynton poynton at poynton.com
|
| + *
|
| + * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
|
| + *
|
| + * which can be expressed with integers as
|
| + *
|
| + * Y = (6969 * R + 23434 * G + 2365 * B)/32768
|
| + *
|
| + * Poynton's current link (as of January 2003 through July 2011):
|
| + * <http://www.poynton.com/notes/colour_and_gamma/>
|
| + * has changed the numbers slightly:
|
| + *
|
| + * Y = 0.2126*R + 0.7152*G + 0.0722*B
|
| + *
|
| + * which can be expressed with integers as
|
| + *
|
| + * Y = (6966 * R + 23436 * G + 2366 * B)/32768
|
| + *
|
| + * Historically, however, libpng uses numbers derived from the ITU-R Rec 709
|
| + * end point chromaticities and the D65 white point. Depending on the
|
| + * precision used for the D65 white point this produces a variety of different
|
| + * numbers, however if the four decimal place value used in ITU-R Rec 709 is
|
| + * used (0.3127,0.3290) the Y calculation would be:
|
| + *
|
| + * Y = (6968 * R + 23435 * G + 2366 * B)/32768
|
| + *
|
| + * While this is correct the rounding results in an overflow for white, because
|
| + * the sum of the rounded coefficients is 32769, not 32768. Consequently
|
| + * libpng uses, instead, the closest non-overflowing approximation:
|
| + *
|
| + * Y = (6968 * R + 23434 * G + 2366 * B)/32768
|
| + *
|
| + * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk
|
| + * (including an sRGB chunk) then the chromaticities are used to calculate the
|
| + * coefficients. See the chunk handling in pngrutil.c for more information.
|
| + *
|
| + * In all cases the calculation is to be done in a linear colorspace. If no
|
| + * gamma information is available to correct the encoding of the original RGB
|
| + * values this results in an implicit assumption that the original PNG RGB
|
| + * values were linear.
|
| + *
|
| + * Other integer coefficents can be used via png_set_rgb_to_gray(). Because
|
| + * the API takes just red and green coefficients the blue coefficient is
|
| + * calculated to make the sum 32768. This will result in different rounding
|
| + * to that used above.
|
| + */
|
| +static int
|
| +png_do_rgb_to_gray(png_structrp png_ptr, png_row_infop row_info, png_bytep row)
|
| +
|
| +{
|
| + int rgb_error = 0;
|
| +
|
| + png_debug(1, "in png_do_rgb_to_gray");
|
| +
|
| + if ((row_info->color_type & PNG_COLOR_MASK_PALETTE) == 0 &&
|
| + (row_info->color_type & PNG_COLOR_MASK_COLOR) != 0)
|
| + {
|
| + PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
|
| + PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
|
| + PNG_CONST png_uint_32 bc = 32768 - rc - gc;
|
| + PNG_CONST png_uint_32 row_width = row_info->width;
|
| + PNG_CONST int have_alpha =
|
| + (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0;
|
| +
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + /* Notice that gamma to/from 1 are not necessarily inverses (if
|
| + * there is an overall gamma correction). Prior to 1.5.5 this code
|
| + * checked the linearized values for equality; this doesn't match
|
| + * the documentation, the original values must be checked.
|
| + */
|
| + if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
|
| + {
|
| + png_bytep sp = row;
|
| + png_bytep dp = row;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_byte red = *(sp++);
|
| + png_byte green = *(sp++);
|
| + png_byte blue = *(sp++);
|
| +
|
| + if (red != green || red != blue)
|
| + {
|
| + red = png_ptr->gamma_to_1[red];
|
| + green = png_ptr->gamma_to_1[green];
|
| + blue = png_ptr->gamma_to_1[blue];
|
| +
|
| + rgb_error |= 1;
|
| + *(dp++) = png_ptr->gamma_from_1[
|
| + (rc*red + gc*green + bc*blue + 16384)>>15];
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* If there is no overall correction the table will not be
|
| + * set.
|
| + */
|
| + if (png_ptr->gamma_table != NULL)
|
| + red = png_ptr->gamma_table[red];
|
| +
|
| + *(dp++) = red;
|
| + }
|
| +
|
| + if (have_alpha != 0)
|
| + *(dp++) = *(sp++);
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + png_bytep sp = row;
|
| + png_bytep dp = row;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_byte red = *(sp++);
|
| + png_byte green = *(sp++);
|
| + png_byte blue = *(sp++);
|
| +
|
| + if (red != green || red != blue)
|
| + {
|
| + rgb_error |= 1;
|
| + /* NOTE: this is the historical approach which simply
|
| + * truncates the results.
|
| + */
|
| + *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
|
| + }
|
| +
|
| + else
|
| + *(dp++) = red;
|
| +
|
| + if (have_alpha != 0)
|
| + *(dp++) = *(sp++);
|
| + }
|
| + }
|
| + }
|
| +
|
| + else /* RGB bit_depth == 16 */
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL)
|
| + {
|
| + png_bytep sp = row;
|
| + png_bytep dp = row;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_uint_16 red, green, blue, w;
|
| + png_byte hi,lo;
|
| +
|
| + hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
|
| + hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
|
| + hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
|
| +
|
| + if (red == green && red == blue)
|
| + {
|
| + if (png_ptr->gamma_16_table != NULL)
|
| + w = png_ptr->gamma_16_table[(red & 0xff)
|
| + >> png_ptr->gamma_shift][red >> 8];
|
| +
|
| + else
|
| + w = red;
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red & 0xff)
|
| + >> png_ptr->gamma_shift][red>>8];
|
| + png_uint_16 green_1 =
|
| + png_ptr->gamma_16_to_1[(green & 0xff) >>
|
| + png_ptr->gamma_shift][green>>8];
|
| + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue & 0xff)
|
| + >> png_ptr->gamma_shift][blue>>8];
|
| + png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
|
| + + bc*blue_1 + 16384)>>15);
|
| + w = png_ptr->gamma_16_from_1[(gray16 & 0xff) >>
|
| + png_ptr->gamma_shift][gray16 >> 8];
|
| + rgb_error |= 1;
|
| + }
|
| +
|
| + *(dp++) = (png_byte)((w>>8) & 0xff);
|
| + *(dp++) = (png_byte)(w & 0xff);
|
| +
|
| + if (have_alpha != 0)
|
| + {
|
| + *(dp++) = *(sp++);
|
| + *(dp++) = *(sp++);
|
| + }
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + png_bytep sp = row;
|
| + png_bytep dp = row;
|
| + png_uint_32 i;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_uint_16 red, green, blue, gray16;
|
| + png_byte hi,lo;
|
| +
|
| + hi=*(sp)++; lo=*(sp)++; red = (png_uint_16)((hi << 8) | (lo));
|
| + hi=*(sp)++; lo=*(sp)++; green = (png_uint_16)((hi << 8) | (lo));
|
| + hi=*(sp)++; lo=*(sp)++; blue = (png_uint_16)((hi << 8) | (lo));
|
| +
|
| + if (red != green || red != blue)
|
| + rgb_error |= 1;
|
| +
|
| + /* From 1.5.5 in the 16-bit case do the accurate conversion even
|
| + * in the 'fast' case - this is because this is where the code
|
| + * ends up when handling linear 16-bit data.
|
| + */
|
| + gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >>
|
| + 15);
|
| + *(dp++) = (png_byte)((gray16 >> 8) & 0xff);
|
| + *(dp++) = (png_byte)(gray16 & 0xff);
|
| +
|
| + if (have_alpha != 0)
|
| + {
|
| + *(dp++) = *(sp++);
|
| + *(dp++) = *(sp++);
|
| + }
|
| + }
|
| + }
|
| + }
|
| +
|
| + row_info->channels = (png_byte)(row_info->channels - 2);
|
| + row_info->color_type = (png_byte)(row_info->color_type &
|
| + ~PNG_COLOR_MASK_COLOR);
|
| + row_info->pixel_depth = (png_byte)(row_info->channels *
|
| + row_info->bit_depth);
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
| + }
|
| + return rgb_error;
|
| +}
|
| +#endif
|
| +
|
| +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
| + defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
| +/* Replace any alpha or transparency with the supplied background color.
|
| + * "background" is already in the screen gamma, while "background_1" is
|
| + * at a gamma of 1.0. Paletted files have already been taken care of.
|
| + */
|
| +static void
|
| +png_do_compose(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
|
| +{
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + png_const_bytep gamma_table = png_ptr->gamma_table;
|
| + png_const_bytep gamma_from_1 = png_ptr->gamma_from_1;
|
| + png_const_bytep gamma_to_1 = png_ptr->gamma_to_1;
|
| + png_const_uint_16pp gamma_16 = png_ptr->gamma_16_table;
|
| + png_const_uint_16pp gamma_16_from_1 = png_ptr->gamma_16_from_1;
|
| + png_const_uint_16pp gamma_16_to_1 = png_ptr->gamma_16_to_1;
|
| + int gamma_shift = png_ptr->gamma_shift;
|
| + int optimize = (png_ptr->flags & PNG_FLAG_OPTIMIZE_ALPHA) != 0;
|
| +#endif
|
| +
|
| + png_bytep sp;
|
| + png_uint_32 i;
|
| + png_uint_32 row_width = row_info->width;
|
| + int shift;
|
| +
|
| + png_debug(1, "in png_do_compose");
|
| +
|
| + {
|
| + switch (row_info->color_type)
|
| + {
|
| + case PNG_COLOR_TYPE_GRAY:
|
| + {
|
| + switch (row_info->bit_depth)
|
| + {
|
| + case 1:
|
| + {
|
| + sp = row;
|
| + shift = 7;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((png_uint_16)((*sp >> shift) & 0x01)
|
| + == png_ptr->trans_color.gray)
|
| + {
|
| + unsigned int tmp = *sp & (0x7f7f >> (7 - shift));
|
| + tmp |= png_ptr->background.gray << shift;
|
| + *sp = (png_byte)(tmp & 0xff);
|
| + }
|
| +
|
| + if (shift == 0)
|
| + {
|
| + shift = 7;
|
| + sp++;
|
| + }
|
| +
|
| + else
|
| + shift--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 2:
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_table != NULL)
|
| + {
|
| + sp = row;
|
| + shift = 6;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((png_uint_16)((*sp >> shift) & 0x03)
|
| + == png_ptr->trans_color.gray)
|
| + {
|
| + unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
|
| + tmp |= png_ptr->background.gray << shift;
|
| + *sp = (png_byte)(tmp & 0xff);
|
| + }
|
| +
|
| + else
|
| + {
|
| + unsigned int p = (*sp >> shift) & 0x03;
|
| + unsigned int g = (gamma_table [p | (p << 2) |
|
| + (p << 4) | (p << 6)] >> 6) & 0x03;
|
| + unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
|
| + tmp |= g << shift;
|
| + *sp = (png_byte)(tmp & 0xff);
|
| + }
|
| +
|
| + if (shift == 0)
|
| + {
|
| + shift = 6;
|
| + sp++;
|
| + }
|
| +
|
| + else
|
| + shift -= 2;
|
| + }
|
| + }
|
| +
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + shift = 6;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((png_uint_16)((*sp >> shift) & 0x03)
|
| + == png_ptr->trans_color.gray)
|
| + {
|
| + unsigned int tmp = *sp & (0x3f3f >> (6 - shift));
|
| + tmp |= png_ptr->background.gray << shift;
|
| + *sp = (png_byte)(tmp & 0xff);
|
| + }
|
| +
|
| + if (shift == 0)
|
| + {
|
| + shift = 6;
|
| + sp++;
|
| + }
|
| +
|
| + else
|
| + shift -= 2;
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 4:
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_table != NULL)
|
| + {
|
| + sp = row;
|
| + shift = 4;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((png_uint_16)((*sp >> shift) & 0x0f)
|
| + == png_ptr->trans_color.gray)
|
| + {
|
| + unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
|
| + tmp |= png_ptr->background.gray << shift;
|
| + *sp = (png_byte)(tmp & 0xff);
|
| + }
|
| +
|
| + else
|
| + {
|
| + unsigned int p = (*sp >> shift) & 0x0f;
|
| + unsigned int g = (gamma_table[p | (p << 4)] >> 4) &
|
| + 0x0f;
|
| + unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
|
| + tmp |= g << shift;
|
| + *sp = (png_byte)(tmp & 0xff);
|
| + }
|
| +
|
| + if (shift == 0)
|
| + {
|
| + shift = 4;
|
| + sp++;
|
| + }
|
| +
|
| + else
|
| + shift -= 4;
|
| + }
|
| + }
|
| +
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + shift = 4;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((png_uint_16)((*sp >> shift) & 0x0f)
|
| + == png_ptr->trans_color.gray)
|
| + {
|
| + unsigned int tmp = *sp & (0x0f0f >> (4 - shift));
|
| + tmp |= png_ptr->background.gray << shift;
|
| + *sp = (png_byte)(tmp & 0xff);
|
| + }
|
| +
|
| + if (shift == 0)
|
| + {
|
| + shift = 4;
|
| + sp++;
|
| + }
|
| +
|
| + else
|
| + shift -= 4;
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 8:
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_table != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp++)
|
| + {
|
| + if (*sp == png_ptr->trans_color.gray)
|
| + *sp = (png_byte)png_ptr->background.gray;
|
| +
|
| + else
|
| + *sp = gamma_table[*sp];
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp++)
|
| + {
|
| + if (*sp == png_ptr->trans_color.gray)
|
| + *sp = (png_byte)png_ptr->background.gray;
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 16:
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_16 != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 2)
|
| + {
|
| + png_uint_16 v;
|
| +
|
| + v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
| +
|
| + if (v == png_ptr->trans_color.gray)
|
| + {
|
| + /* Background is already in screen gamma */
|
| + *sp = (png_byte)((png_ptr->background.gray >> 8)
|
| + & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.gray
|
| + & 0xff);
|
| + }
|
| +
|
| + else
|
| + {
|
| + v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + }
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 2)
|
| + {
|
| + png_uint_16 v;
|
| +
|
| + v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
| +
|
| + if (v == png_ptr->trans_color.gray)
|
| + {
|
| + *sp = (png_byte)((png_ptr->background.gray >> 8)
|
| + & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.gray
|
| + & 0xff);
|
| + }
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + default:
|
| + break;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case PNG_COLOR_TYPE_RGB:
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_table != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 3)
|
| + {
|
| + if (*sp == png_ptr->trans_color.red &&
|
| + *(sp + 1) == png_ptr->trans_color.green &&
|
| + *(sp + 2) == png_ptr->trans_color.blue)
|
| + {
|
| + *sp = (png_byte)png_ptr->background.red;
|
| + *(sp + 1) = (png_byte)png_ptr->background.green;
|
| + *(sp + 2) = (png_byte)png_ptr->background.blue;
|
| + }
|
| +
|
| + else
|
| + {
|
| + *sp = gamma_table[*sp];
|
| + *(sp + 1) = gamma_table[*(sp + 1)];
|
| + *(sp + 2) = gamma_table[*(sp + 2)];
|
| + }
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 3)
|
| + {
|
| + if (*sp == png_ptr->trans_color.red &&
|
| + *(sp + 1) == png_ptr->trans_color.green &&
|
| + *(sp + 2) == png_ptr->trans_color.blue)
|
| + {
|
| + *sp = (png_byte)png_ptr->background.red;
|
| + *(sp + 1) = (png_byte)png_ptr->background.green;
|
| + *(sp + 2) = (png_byte)png_ptr->background.blue;
|
| + }
|
| + }
|
| + }
|
| + }
|
| + else /* if (row_info->bit_depth == 16) */
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_16 != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 6)
|
| + {
|
| + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
| +
|
| + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
|
| + + *(sp + 3));
|
| +
|
| + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
|
| + + *(sp + 5));
|
| +
|
| + if (r == png_ptr->trans_color.red &&
|
| + g == png_ptr->trans_color.green &&
|
| + b == png_ptr->trans_color.blue)
|
| + {
|
| + /* Background is already in screen gamma */
|
| + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
| + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
| + & 0xff);
|
| + *(sp + 3) = (png_byte)(png_ptr->background.green
|
| + & 0xff);
|
| + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
| + & 0xff);
|
| + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| +
|
| + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
| + *(sp + 2) = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 3) = (png_byte)(v & 0xff);
|
| +
|
| + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
| + *(sp + 4) = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 5) = (png_byte)(v & 0xff);
|
| + }
|
| + }
|
| + }
|
| +
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 6)
|
| + {
|
| + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
| +
|
| + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
|
| + + *(sp + 3));
|
| +
|
| + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
|
| + + *(sp + 5));
|
| +
|
| + if (r == png_ptr->trans_color.red &&
|
| + g == png_ptr->trans_color.green &&
|
| + b == png_ptr->trans_color.blue)
|
| + {
|
| + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
| + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
| + & 0xff);
|
| + *(sp + 3) = (png_byte)(png_ptr->background.green
|
| + & 0xff);
|
| + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
| + & 0xff);
|
| + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
| + }
|
| + }
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case PNG_COLOR_TYPE_GRAY_ALPHA:
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
|
| + gamma_table != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 2)
|
| + {
|
| + png_uint_16 a = *(sp + 1);
|
| +
|
| + if (a == 0xff)
|
| + *sp = gamma_table[*sp];
|
| +
|
| + else if (a == 0)
|
| + {
|
| + /* Background is already in screen gamma */
|
| + *sp = (png_byte)png_ptr->background.gray;
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_byte v, w;
|
| +
|
| + v = gamma_to_1[*sp];
|
| + png_composite(w, v, a, png_ptr->background_1.gray);
|
| + if (optimize == 0)
|
| + w = gamma_from_1[w];
|
| + *sp = w;
|
| + }
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 2)
|
| + {
|
| + png_byte a = *(sp + 1);
|
| +
|
| + if (a == 0)
|
| + *sp = (png_byte)png_ptr->background.gray;
|
| +
|
| + else if (a < 0xff)
|
| + png_composite(*sp, *sp, a, png_ptr->background.gray);
|
| + }
|
| + }
|
| + }
|
| + else /* if (png_ptr->bit_depth == 16) */
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
|
| + gamma_16_to_1 != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 4)
|
| + {
|
| + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
|
| + + *(sp + 3));
|
| +
|
| + if (a == (png_uint_16)0xffff)
|
| + {
|
| + png_uint_16 v;
|
| +
|
| + v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + }
|
| +
|
| + else if (a == 0)
|
| + {
|
| + /* Background is already in screen gamma */
|
| + *sp = (png_byte)((png_ptr->background.gray >> 8)
|
| + & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_uint_16 g, v, w;
|
| +
|
| + g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
|
| + png_composite_16(v, g, a, png_ptr->background_1.gray);
|
| + if (optimize != 0)
|
| + w = v;
|
| + else
|
| + w = gamma_16_from_1[(v & 0xff) >>
|
| + gamma_shift][v >> 8];
|
| + *sp = (png_byte)((w >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(w & 0xff);
|
| + }
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 4)
|
| + {
|
| + png_uint_16 a = (png_uint_16)(((*(sp + 2)) << 8)
|
| + + *(sp + 3));
|
| +
|
| + if (a == 0)
|
| + {
|
| + *sp = (png_byte)((png_ptr->background.gray >> 8)
|
| + & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.gray & 0xff);
|
| + }
|
| +
|
| + else if (a < 0xffff)
|
| + {
|
| + png_uint_16 g, v;
|
| +
|
| + g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
| + png_composite_16(v, g, a, png_ptr->background.gray);
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + }
|
| + }
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case PNG_COLOR_TYPE_RGB_ALPHA:
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
|
| + gamma_table != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 4)
|
| + {
|
| + png_byte a = *(sp + 3);
|
| +
|
| + if (a == 0xff)
|
| + {
|
| + *sp = gamma_table[*sp];
|
| + *(sp + 1) = gamma_table[*(sp + 1)];
|
| + *(sp + 2) = gamma_table[*(sp + 2)];
|
| + }
|
| +
|
| + else if (a == 0)
|
| + {
|
| + /* Background is already in screen gamma */
|
| + *sp = (png_byte)png_ptr->background.red;
|
| + *(sp + 1) = (png_byte)png_ptr->background.green;
|
| + *(sp + 2) = (png_byte)png_ptr->background.blue;
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_byte v, w;
|
| +
|
| + v = gamma_to_1[*sp];
|
| + png_composite(w, v, a, png_ptr->background_1.red);
|
| + if (optimize == 0) w = gamma_from_1[w];
|
| + *sp = w;
|
| +
|
| + v = gamma_to_1[*(sp + 1)];
|
| + png_composite(w, v, a, png_ptr->background_1.green);
|
| + if (optimize == 0) w = gamma_from_1[w];
|
| + *(sp + 1) = w;
|
| +
|
| + v = gamma_to_1[*(sp + 2)];
|
| + png_composite(w, v, a, png_ptr->background_1.blue);
|
| + if (optimize == 0) w = gamma_from_1[w];
|
| + *(sp + 2) = w;
|
| + }
|
| + }
|
| + }
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 4)
|
| + {
|
| + png_byte a = *(sp + 3);
|
| +
|
| + if (a == 0)
|
| + {
|
| + *sp = (png_byte)png_ptr->background.red;
|
| + *(sp + 1) = (png_byte)png_ptr->background.green;
|
| + *(sp + 2) = (png_byte)png_ptr->background.blue;
|
| + }
|
| +
|
| + else if (a < 0xff)
|
| + {
|
| + png_composite(*sp, *sp, a, png_ptr->background.red);
|
| +
|
| + png_composite(*(sp + 1), *(sp + 1), a,
|
| + png_ptr->background.green);
|
| +
|
| + png_composite(*(sp + 2), *(sp + 2), a,
|
| + png_ptr->background.blue);
|
| + }
|
| + }
|
| + }
|
| + }
|
| + else /* if (row_info->bit_depth == 16) */
|
| + {
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
|
| + gamma_16_to_1 != NULL)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 8)
|
| + {
|
| + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
|
| + << 8) + (png_uint_16)(*(sp + 7)));
|
| +
|
| + if (a == (png_uint_16)0xffff)
|
| + {
|
| + png_uint_16 v;
|
| +
|
| + v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| +
|
| + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
| + *(sp + 2) = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 3) = (png_byte)(v & 0xff);
|
| +
|
| + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
| + *(sp + 4) = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 5) = (png_byte)(v & 0xff);
|
| + }
|
| +
|
| + else if (a == 0)
|
| + {
|
| + /* Background is already in screen gamma */
|
| + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
| + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
| + & 0xff);
|
| + *(sp + 3) = (png_byte)(png_ptr->background.green
|
| + & 0xff);
|
| + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
| + & 0xff);
|
| + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_uint_16 v, w;
|
| +
|
| + v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
|
| + png_composite_16(w, v, a, png_ptr->background_1.red);
|
| + if (optimize == 0)
|
| + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
|
| + 8];
|
| + *sp = (png_byte)((w >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(w & 0xff);
|
| +
|
| + v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
| + png_composite_16(w, v, a, png_ptr->background_1.green);
|
| + if (optimize == 0)
|
| + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
|
| + 8];
|
| +
|
| + *(sp + 2) = (png_byte)((w >> 8) & 0xff);
|
| + *(sp + 3) = (png_byte)(w & 0xff);
|
| +
|
| + v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
| + png_composite_16(w, v, a, png_ptr->background_1.blue);
|
| + if (optimize == 0)
|
| + w = gamma_16_from_1[((w & 0xff) >> gamma_shift)][w >>
|
| + 8];
|
| +
|
| + *(sp + 4) = (png_byte)((w >> 8) & 0xff);
|
| + *(sp + 5) = (png_byte)(w & 0xff);
|
| + }
|
| + }
|
| + }
|
| +
|
| + else
|
| +#endif
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++, sp += 8)
|
| + {
|
| + png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
|
| + << 8) + (png_uint_16)(*(sp + 7)));
|
| +
|
| + if (a == 0)
|
| + {
|
| + *sp = (png_byte)((png_ptr->background.red >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(png_ptr->background.red & 0xff);
|
| + *(sp + 2) = (png_byte)((png_ptr->background.green >> 8)
|
| + & 0xff);
|
| + *(sp + 3) = (png_byte)(png_ptr->background.green
|
| + & 0xff);
|
| + *(sp + 4) = (png_byte)((png_ptr->background.blue >> 8)
|
| + & 0xff);
|
| + *(sp + 5) = (png_byte)(png_ptr->background.blue & 0xff);
|
| + }
|
| +
|
| + else if (a < 0xffff)
|
| + {
|
| + png_uint_16 v;
|
| +
|
| + png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
| + png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
|
| + + *(sp + 3));
|
| + png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
|
| + + *(sp + 5));
|
| +
|
| + png_composite_16(v, r, a, png_ptr->background.red);
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| +
|
| + png_composite_16(v, g, a, png_ptr->background.green);
|
| + *(sp + 2) = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 3) = (png_byte)(v & 0xff);
|
| +
|
| + png_composite_16(v, b, a, png_ptr->background.blue);
|
| + *(sp + 4) = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 5) = (png_byte)(v & 0xff);
|
| + }
|
| + }
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + default:
|
| + break;
|
| + }
|
| + }
|
| +}
|
| +#endif /* READ_BACKGROUND || READ_ALPHA_MODE */
|
| +
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| +/* Gamma correct the image, avoiding the alpha channel. Make sure
|
| + * you do this after you deal with the transparency issue on grayscale
|
| + * or RGB images. If your bit depth is 8, use gamma_table, if it
|
| + * is 16, use gamma_16_table and gamma_shift. Build these with
|
| + * build_gamma_table().
|
| + */
|
| +static void
|
| +png_do_gamma(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
|
| +{
|
| + png_const_bytep gamma_table = png_ptr->gamma_table;
|
| + png_const_uint_16pp gamma_16_table = png_ptr->gamma_16_table;
|
| + int gamma_shift = png_ptr->gamma_shift;
|
| +
|
| + png_bytep sp;
|
| + png_uint_32 i;
|
| + png_uint_32 row_width=row_info->width;
|
| +
|
| + png_debug(1, "in png_do_gamma");
|
| +
|
| + if (((row_info->bit_depth <= 8 && gamma_table != NULL) ||
|
| + (row_info->bit_depth == 16 && gamma_16_table != NULL)))
|
| + {
|
| + switch (row_info->color_type)
|
| + {
|
| + case PNG_COLOR_TYPE_RGB:
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *sp = gamma_table[*sp];
|
| + sp++;
|
| + *sp = gamma_table[*sp];
|
| + sp++;
|
| + *sp = gamma_table[*sp];
|
| + sp++;
|
| + }
|
| + }
|
| +
|
| + else /* if (row_info->bit_depth == 16) */
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_uint_16 v;
|
| +
|
| + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 2;
|
| +
|
| + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 2;
|
| +
|
| + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 2;
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case PNG_COLOR_TYPE_RGB_ALPHA:
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *sp = gamma_table[*sp];
|
| + sp++;
|
| +
|
| + *sp = gamma_table[*sp];
|
| + sp++;
|
| +
|
| + *sp = gamma_table[*sp];
|
| + sp++;
|
| +
|
| + sp++;
|
| + }
|
| + }
|
| +
|
| + else /* if (row_info->bit_depth == 16) */
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 2;
|
| +
|
| + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 2;
|
| +
|
| + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 4;
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case PNG_COLOR_TYPE_GRAY_ALPHA:
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *sp = gamma_table[*sp];
|
| + sp += 2;
|
| + }
|
| + }
|
| +
|
| + else /* if (row_info->bit_depth == 16) */
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 4;
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case PNG_COLOR_TYPE_GRAY:
|
| + {
|
| + if (row_info->bit_depth == 2)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i += 4)
|
| + {
|
| + int a = *sp & 0xc0;
|
| + int b = *sp & 0x30;
|
| + int c = *sp & 0x0c;
|
| + int d = *sp & 0x03;
|
| +
|
| + *sp = (png_byte)(
|
| + ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
|
| + ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
|
| + ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
|
| + ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
|
| + sp++;
|
| + }
|
| + }
|
| +
|
| + if (row_info->bit_depth == 4)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i += 2)
|
| + {
|
| + int msb = *sp & 0xf0;
|
| + int lsb = *sp & 0x0f;
|
| +
|
| + *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
|
| + | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
|
| + sp++;
|
| + }
|
| + }
|
| +
|
| + else if (row_info->bit_depth == 8)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *sp = gamma_table[*sp];
|
| + sp++;
|
| + }
|
| + }
|
| +
|
| + else if (row_info->bit_depth == 16)
|
| + {
|
| + sp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
| + *sp = (png_byte)((v >> 8) & 0xff);
|
| + *(sp + 1) = (png_byte)(v & 0xff);
|
| + sp += 2;
|
| + }
|
| + }
|
| + break;
|
| + }
|
| +
|
| + default:
|
| + break;
|
| + }
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
| +/* Encode the alpha channel to the output gamma (the input channel is always
|
| + * linear.) Called only with color types that have an alpha channel. Needs the
|
| + * from_1 tables.
|
| + */
|
| +static void
|
| +png_do_encode_alpha(png_row_infop row_info, png_bytep row, png_structrp png_ptr)
|
| +{
|
| + png_uint_32 row_width = row_info->width;
|
| +
|
| + png_debug(1, "in png_do_encode_alpha");
|
| +
|
| + if ((row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + PNG_CONST png_bytep table = png_ptr->gamma_from_1;
|
| +
|
| + if (table != NULL)
|
| + {
|
| + PNG_CONST int step =
|
| + (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 4 : 2;
|
| +
|
| + /* The alpha channel is the last component: */
|
| + row += step - 1;
|
| +
|
| + for (; row_width > 0; --row_width, row += step)
|
| + *row = table[*row];
|
| +
|
| + return;
|
| + }
|
| + }
|
| +
|
| + else if (row_info->bit_depth == 16)
|
| + {
|
| + PNG_CONST png_uint_16pp table = png_ptr->gamma_16_from_1;
|
| + PNG_CONST int gamma_shift = png_ptr->gamma_shift;
|
| +
|
| + if (table != NULL)
|
| + {
|
| + PNG_CONST int step =
|
| + (row_info->color_type & PNG_COLOR_MASK_COLOR) ? 8 : 4;
|
| +
|
| + /* The alpha channel is the last component: */
|
| + row += step - 2;
|
| +
|
| + for (; row_width > 0; --row_width, row += step)
|
| + {
|
| + png_uint_16 v;
|
| +
|
| + v = table[*(row + 1) >> gamma_shift][*row];
|
| + *row = (png_byte)((v >> 8) & 0xff);
|
| + *(row + 1) = (png_byte)(v & 0xff);
|
| + }
|
| +
|
| + return;
|
| + }
|
| + }
|
| + }
|
| +
|
| + /* Only get to here if called with a weird row_info; no harm has been done,
|
| + * so just issue a warning.
|
| + */
|
| + png_warning(png_ptr, "png_do_encode_alpha: unexpected call");
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_EXPAND_SUPPORTED
|
| +/* Expands a palette row to an RGB or RGBA row depending
|
| + * upon whether you supply trans and num_trans.
|
| + */
|
| +static void
|
| +png_do_expand_palette(png_row_infop row_info, png_bytep row,
|
| + png_const_colorp palette, png_const_bytep trans_alpha, int num_trans)
|
| +{
|
| + int shift, value;
|
| + png_bytep sp, dp;
|
| + png_uint_32 i;
|
| + png_uint_32 row_width=row_info->width;
|
| +
|
| + png_debug(1, "in png_do_expand_palette");
|
| +
|
| + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + if (row_info->bit_depth < 8)
|
| + {
|
| + switch (row_info->bit_depth)
|
| + {
|
| + case 1:
|
| + {
|
| + sp = row + (png_size_t)((row_width - 1) >> 3);
|
| + dp = row + (png_size_t)row_width - 1;
|
| + shift = 7 - (int)((row_width + 7) & 0x07);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((*sp >> shift) & 0x01)
|
| + *dp = 1;
|
| +
|
| + else
|
| + *dp = 0;
|
| +
|
| + if (shift == 7)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift++;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 2:
|
| + {
|
| + sp = row + (png_size_t)((row_width - 1) >> 2);
|
| + dp = row + (png_size_t)row_width - 1;
|
| + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + value = (*sp >> shift) & 0x03;
|
| + *dp = (png_byte)value;
|
| + if (shift == 6)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift += 2;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 4:
|
| + {
|
| + sp = row + (png_size_t)((row_width - 1) >> 1);
|
| + dp = row + (png_size_t)row_width - 1;
|
| + shift = (int)((row_width & 0x01) << 2);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + value = (*sp >> shift) & 0x0f;
|
| + *dp = (png_byte)value;
|
| + if (shift == 4)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift += 4;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + default:
|
| + break;
|
| + }
|
| + row_info->bit_depth = 8;
|
| + row_info->pixel_depth = 8;
|
| + row_info->rowbytes = row_width;
|
| + }
|
| +
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + {
|
| + if (num_trans > 0)
|
| + {
|
| + sp = row + (png_size_t)row_width - 1;
|
| + dp = row + (png_size_t)(row_width << 2) - 1;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((int)(*sp) >= num_trans)
|
| + *dp-- = 0xff;
|
| +
|
| + else
|
| + *dp-- = trans_alpha[*sp];
|
| +
|
| + *dp-- = palette[*sp].blue;
|
| + *dp-- = palette[*sp].green;
|
| + *dp-- = palette[*sp].red;
|
| + sp--;
|
| + }
|
| + row_info->bit_depth = 8;
|
| + row_info->pixel_depth = 32;
|
| + row_info->rowbytes = row_width * 4;
|
| + row_info->color_type = 6;
|
| + row_info->channels = 4;
|
| + }
|
| +
|
| + else
|
| + {
|
| + sp = row + (png_size_t)row_width - 1;
|
| + dp = row + (png_size_t)(row_width * 3) - 1;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + *dp-- = palette[*sp].blue;
|
| + *dp-- = palette[*sp].green;
|
| + *dp-- = palette[*sp].red;
|
| + sp--;
|
| + }
|
| +
|
| + row_info->bit_depth = 8;
|
| + row_info->pixel_depth = 24;
|
| + row_info->rowbytes = row_width * 3;
|
| + row_info->color_type = 2;
|
| + row_info->channels = 3;
|
| + }
|
| + }
|
| + }
|
| + }
|
| +}
|
| +
|
| +/* If the bit depth < 8, it is expanded to 8. Also, if the already
|
| + * expanded transparency value is supplied, an alpha channel is built.
|
| + */
|
| +static void
|
| +png_do_expand(png_row_infop row_info, png_bytep row,
|
| + png_const_color_16p trans_color)
|
| +{
|
| + int shift, value;
|
| + png_bytep sp, dp;
|
| + png_uint_32 i;
|
| + png_uint_32 row_width=row_info->width;
|
| +
|
| + png_debug(1, "in png_do_expand");
|
| +
|
| + {
|
| + if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
| + {
|
| + unsigned int gray = trans_color != NULL ? trans_color->gray : 0;
|
| +
|
| + if (row_info->bit_depth < 8)
|
| + {
|
| + switch (row_info->bit_depth)
|
| + {
|
| + case 1:
|
| + {
|
| + gray = (gray & 0x01) * 0xff;
|
| + sp = row + (png_size_t)((row_width - 1) >> 3);
|
| + dp = row + (png_size_t)row_width - 1;
|
| + shift = 7 - (int)((row_width + 7) & 0x07);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((*sp >> shift) & 0x01)
|
| + *dp = 0xff;
|
| +
|
| + else
|
| + *dp = 0;
|
| +
|
| + if (shift == 7)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift++;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 2:
|
| + {
|
| + gray = (gray & 0x03) * 0x55;
|
| + sp = row + (png_size_t)((row_width - 1) >> 2);
|
| + dp = row + (png_size_t)row_width - 1;
|
| + shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + value = (*sp >> shift) & 0x03;
|
| + *dp = (png_byte)(value | (value << 2) | (value << 4) |
|
| + (value << 6));
|
| + if (shift == 6)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift += 2;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + case 4:
|
| + {
|
| + gray = (gray & 0x0f) * 0x11;
|
| + sp = row + (png_size_t)((row_width - 1) >> 1);
|
| + dp = row + (png_size_t)row_width - 1;
|
| + shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + value = (*sp >> shift) & 0x0f;
|
| + *dp = (png_byte)(value | (value << 4));
|
| + if (shift == 4)
|
| + {
|
| + shift = 0;
|
| + sp--;
|
| + }
|
| +
|
| + else
|
| + shift = 4;
|
| +
|
| + dp--;
|
| + }
|
| + break;
|
| + }
|
| +
|
| + default:
|
| + break;
|
| + }
|
| +
|
| + row_info->bit_depth = 8;
|
| + row_info->pixel_depth = 8;
|
| + row_info->rowbytes = row_width;
|
| + }
|
| +
|
| + if (trans_color != NULL)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + gray = gray & 0xff;
|
| + sp = row + (png_size_t)row_width - 1;
|
| + dp = row + (png_size_t)(row_width << 1) - 1;
|
| +
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((*sp & 0xffU) == gray)
|
| + *dp-- = 0;
|
| +
|
| + else
|
| + *dp-- = 0xff;
|
| +
|
| + *dp-- = *sp--;
|
| + }
|
| + }
|
| +
|
| + else if (row_info->bit_depth == 16)
|
| + {
|
| + unsigned int gray_high = (gray >> 8) & 0xff;
|
| + unsigned int gray_low = gray & 0xff;
|
| + sp = row + row_info->rowbytes - 1;
|
| + dp = row + (row_info->rowbytes << 1) - 1;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if ((*(sp - 1) & 0xffU) == gray_high &&
|
| + (*(sp) & 0xffU) == gray_low)
|
| + {
|
| + *dp-- = 0;
|
| + *dp-- = 0;
|
| + }
|
| +
|
| + else
|
| + {
|
| + *dp-- = 0xff;
|
| + *dp-- = 0xff;
|
| + }
|
| +
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + }
|
| + }
|
| +
|
| + row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
|
| + row_info->channels = 2;
|
| + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
|
| + row_width);
|
| + }
|
| + }
|
| + else if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
|
| + trans_color != NULL)
|
| + {
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + png_byte red = (png_byte)(trans_color->red & 0xff);
|
| + png_byte green = (png_byte)(trans_color->green & 0xff);
|
| + png_byte blue = (png_byte)(trans_color->blue & 0xff);
|
| + sp = row + (png_size_t)row_info->rowbytes - 1;
|
| + dp = row + (png_size_t)(row_width << 2) - 1;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
|
| + *dp-- = 0;
|
| +
|
| + else
|
| + *dp-- = 0xff;
|
| +
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + }
|
| + }
|
| + else if (row_info->bit_depth == 16)
|
| + {
|
| + png_byte red_high = (png_byte)((trans_color->red >> 8) & 0xff);
|
| + png_byte green_high = (png_byte)((trans_color->green >> 8) & 0xff);
|
| + png_byte blue_high = (png_byte)((trans_color->blue >> 8) & 0xff);
|
| + png_byte red_low = (png_byte)(trans_color->red & 0xff);
|
| + png_byte green_low = (png_byte)(trans_color->green & 0xff);
|
| + png_byte blue_low = (png_byte)(trans_color->blue & 0xff);
|
| + sp = row + row_info->rowbytes - 1;
|
| + dp = row + (png_size_t)(row_width << 3) - 1;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + if (*(sp - 5) == red_high &&
|
| + *(sp - 4) == red_low &&
|
| + *(sp - 3) == green_high &&
|
| + *(sp - 2) == green_low &&
|
| + *(sp - 1) == blue_high &&
|
| + *(sp ) == blue_low)
|
| + {
|
| + *dp-- = 0;
|
| + *dp-- = 0;
|
| + }
|
| +
|
| + else
|
| + {
|
| + *dp-- = 0xff;
|
| + *dp-- = 0xff;
|
| + }
|
| +
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + *dp-- = *sp--;
|
| + }
|
| + }
|
| + row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
| + row_info->channels = 4;
|
| + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
| + }
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
| +/* If the bit depth is 8 and the color type is not a palette type expand the
|
| + * whole row to 16 bits. Has no effect otherwise.
|
| + */
|
| +static void
|
| +png_do_expand_16(png_row_infop row_info, png_bytep row)
|
| +{
|
| + if (row_info->bit_depth == 8 &&
|
| + row_info->color_type != PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + /* The row have a sequence of bytes containing [0..255] and we need
|
| + * to turn it into another row containing [0..65535], to do this we
|
| + * calculate:
|
| + *
|
| + * (input / 255) * 65535
|
| + *
|
| + * Which happens to be exactly input * 257 and this can be achieved
|
| + * simply by byte replication in place (copying backwards).
|
| + */
|
| + png_byte *sp = row + row_info->rowbytes; /* source, last byte + 1 */
|
| + png_byte *dp = sp + row_info->rowbytes; /* destination, end + 1 */
|
| + while (dp > sp)
|
| + dp[-2] = dp[-1] = *--sp, dp -= 2;
|
| +
|
| + row_info->rowbytes *= 2;
|
| + row_info->bit_depth = 16;
|
| + row_info->pixel_depth = (png_byte)(row_info->channels * 16);
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
| +static void
|
| +png_do_quantize(png_row_infop row_info, png_bytep row,
|
| + png_const_bytep palette_lookup, png_const_bytep quantize_lookup)
|
| +{
|
| + png_bytep sp, dp;
|
| + png_uint_32 i;
|
| + png_uint_32 row_width=row_info->width;
|
| +
|
| + png_debug(1, "in png_do_quantize");
|
| +
|
| + if (row_info->bit_depth == 8)
|
| + {
|
| + if (row_info->color_type == PNG_COLOR_TYPE_RGB && palette_lookup)
|
| + {
|
| + int r, g, b, p;
|
| + sp = row;
|
| + dp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + r = *sp++;
|
| + g = *sp++;
|
| + b = *sp++;
|
| +
|
| + /* This looks real messy, but the compiler will reduce
|
| + * it down to a reasonable formula. For example, with
|
| + * 5 bits per color, we get:
|
| + * p = (((r >> 3) & 0x1f) << 10) |
|
| + * (((g >> 3) & 0x1f) << 5) |
|
| + * ((b >> 3) & 0x1f);
|
| + */
|
| + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
|
| + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
|
| + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
|
| + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
|
| + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
|
| + (PNG_QUANTIZE_BLUE_BITS)) |
|
| + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
|
| + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
|
| +
|
| + *dp++ = palette_lookup[p];
|
| + }
|
| +
|
| + row_info->color_type = PNG_COLOR_TYPE_PALETTE;
|
| + row_info->channels = 1;
|
| + row_info->pixel_depth = row_info->bit_depth;
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
| + }
|
| +
|
| + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
|
| + palette_lookup != NULL)
|
| + {
|
| + int r, g, b, p;
|
| + sp = row;
|
| + dp = row;
|
| + for (i = 0; i < row_width; i++)
|
| + {
|
| + r = *sp++;
|
| + g = *sp++;
|
| + b = *sp++;
|
| + sp++;
|
| +
|
| + p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
|
| + ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
|
| + (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
|
| + (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
|
| + ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
|
| + (PNG_QUANTIZE_BLUE_BITS)) |
|
| + ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
|
| + ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
|
| +
|
| + *dp++ = palette_lookup[p];
|
| + }
|
| +
|
| + row_info->color_type = PNG_COLOR_TYPE_PALETTE;
|
| + row_info->channels = 1;
|
| + row_info->pixel_depth = row_info->bit_depth;
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
| + }
|
| +
|
| + else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
|
| + quantize_lookup)
|
| + {
|
| + sp = row;
|
| +
|
| + for (i = 0; i < row_width; i++, sp++)
|
| + {
|
| + *sp = quantize_lookup[*sp];
|
| + }
|
| + }
|
| + }
|
| +}
|
| +#endif /* READ_QUANTIZE */
|
| +
|
| +/* Transform the row. The order of transformations is significant,
|
| + * and is very touchy. If you add a transformation, take care to
|
| + * decide how it fits in with the other transformations here.
|
| + */
|
| +void /* PRIVATE */
|
| +png_do_read_transformations(png_structrp png_ptr, png_row_infop row_info)
|
| +{
|
| + png_debug(1, "in png_do_read_transformations");
|
| +
|
| + if (png_ptr->row_buf == NULL)
|
| + {
|
| + /* Prior to 1.5.4 this output row/pass where the NULL pointer is, but this
|
| + * error is incredibly rare and incredibly easy to debug without this
|
| + * information.
|
| + */
|
| + png_error(png_ptr, "NULL row buffer");
|
| + }
|
| +
|
| + /* The following is debugging; prior to 1.5.4 the code was never compiled in;
|
| + * in 1.5.4 PNG_FLAG_DETECT_UNINITIALIZED was added and the macro
|
| + * PNG_WARN_UNINITIALIZED_ROW removed. In 1.6 the new flag is set only for
|
| + * all transformations, however in practice the ROW_INIT always gets done on
|
| + * demand, if necessary.
|
| + */
|
| + if ((png_ptr->flags & PNG_FLAG_DETECT_UNINITIALIZED) != 0 &&
|
| + (png_ptr->flags & PNG_FLAG_ROW_INIT) == 0)
|
| + {
|
| + /* Application has failed to call either png_read_start_image() or
|
| + * png_read_update_info() after setting transforms that expand pixels.
|
| + * This check added to libpng-1.2.19 (but not enabled until 1.5.4).
|
| + */
|
| + png_error(png_ptr, "Uninitialized row");
|
| + }
|
| +
|
| +#ifdef PNG_READ_EXPAND_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_EXPAND) != 0)
|
| + {
|
| + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + png_do_expand_palette(row_info, png_ptr->row_buf + 1,
|
| + png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
|
| + }
|
| +
|
| + else
|
| + {
|
| + if (png_ptr->num_trans != 0 &&
|
| + (png_ptr->transformations & PNG_EXPAND_tRNS) != 0)
|
| + png_do_expand(row_info, png_ptr->row_buf + 1,
|
| + &(png_ptr->trans_color));
|
| +
|
| + else
|
| + png_do_expand(row_info, png_ptr->row_buf + 1,
|
| + NULL);
|
| + }
|
| + }
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
|
| + (png_ptr->transformations & PNG_COMPOSE) == 0 &&
|
| + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
|
| + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
|
| + png_do_strip_channel(row_info, png_ptr->row_buf + 1,
|
| + 0 /* at_start == false, because SWAP_ALPHA happens later */);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) != 0)
|
| + {
|
| + int rgb_error =
|
| + png_do_rgb_to_gray(png_ptr, row_info,
|
| + png_ptr->row_buf + 1);
|
| +
|
| + if (rgb_error != 0)
|
| + {
|
| + png_ptr->rgb_to_gray_status=1;
|
| + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
|
| + PNG_RGB_TO_GRAY_WARN)
|
| + png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
|
| +
|
| + if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
|
| + PNG_RGB_TO_GRAY_ERR)
|
| + png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
|
| + }
|
| + }
|
| +#endif
|
| +
|
| +/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
|
| + *
|
| + * In most cases, the "simple transparency" should be done prior to doing
|
| + * gray-to-RGB, or you will have to test 3x as many bytes to check if a
|
| + * pixel is transparent. You would also need to make sure that the
|
| + * transparency information is upgraded to RGB.
|
| + *
|
| + * To summarize, the current flow is:
|
| + * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
|
| + * with background "in place" if transparent,
|
| + * convert to RGB if necessary
|
| + * - Gray + alpha -> composite with gray background and remove alpha bytes,
|
| + * convert to RGB if necessary
|
| + *
|
| + * To support RGB backgrounds for gray images we need:
|
| + * - Gray + simple transparency -> convert to RGB + simple transparency,
|
| + * compare 3 or 6 bytes and composite with
|
| + * background "in place" if transparent
|
| + * (3x compare/pixel compared to doing
|
| + * composite with gray bkgrnd)
|
| + * - Gray + alpha -> convert to RGB + alpha, composite with background and
|
| + * remove alpha bytes (3x float
|
| + * operations/pixel compared with composite
|
| + * on gray background)
|
| + *
|
| + * Greg's change will do this. The reason it wasn't done before is for
|
| + * performance, as this increases the per-pixel operations. If we would check
|
| + * in advance if the background was gray or RGB, and position the gray-to-RGB
|
| + * transform appropriately, then it would save a lot of work/time.
|
| + */
|
| +
|
| +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
| + /* If gray -> RGB, do so now only if background is non-gray; else do later
|
| + * for performance reasons
|
| + */
|
| + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
|
| + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) == 0)
|
| + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
| + defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
| + if ((png_ptr->transformations & PNG_COMPOSE) != 0)
|
| + png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_GAMMA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_GAMMA) != 0 &&
|
| +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
|
| + /* Because RGB_TO_GRAY does the gamma transform. */
|
| + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0 &&
|
| +#endif
|
| +#if defined(PNG_READ_BACKGROUND_SUPPORTED) ||\
|
| + defined(PNG_READ_ALPHA_MODE_SUPPORTED)
|
| + /* Because PNG_COMPOSE does the gamma transform if there is something to
|
| + * do (if there is an alpha channel or transparency.)
|
| + */
|
| + !((png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
| + ((png_ptr->num_trans != 0) ||
|
| + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) != 0)) &&
|
| +#endif
|
| + /* Because png_init_read_transformations transforms the palette, unless
|
| + * RGB_TO_GRAY will do the transform.
|
| + */
|
| + (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
|
| + png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_STRIP_ALPHA) != 0 &&
|
| + (png_ptr->transformations & PNG_COMPOSE) != 0 &&
|
| + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
|
| + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
|
| + png_do_strip_channel(row_info, png_ptr->row_buf + 1,
|
| + 0 /* at_start == false, because SWAP_ALPHA happens later */);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_ALPHA_MODE_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_ENCODE_ALPHA) != 0 &&
|
| + (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0)
|
| + png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_SCALE_16_TO_8) != 0)
|
| + png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
|
| + /* There is no harm in doing both of these because only one has any effect,
|
| + * by putting the 'scale' option first if the app asks for scale (either by
|
| + * calling the API or in a TRANSFORM flag) this is what happens.
|
| + */
|
| + if ((png_ptr->transformations & PNG_16_TO_8) != 0)
|
| + png_do_chop(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_QUANTIZE_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_QUANTIZE) != 0)
|
| + {
|
| + png_do_quantize(row_info, png_ptr->row_buf + 1,
|
| + png_ptr->palette_lookup, png_ptr->quantize_index);
|
| +
|
| + if (row_info->rowbytes == 0)
|
| + png_error(png_ptr, "png_do_quantize returned rowbytes=0");
|
| + }
|
| +#endif /* READ_QUANTIZE */
|
| +
|
| +#ifdef PNG_READ_EXPAND_16_SUPPORTED
|
| + /* Do the expansion now, after all the arithmetic has been done. Notice
|
| + * that previous transformations can handle the PNG_EXPAND_16 flag if this
|
| + * is efficient (particularly true in the case of gamma correction, where
|
| + * better accuracy results faster!)
|
| + */
|
| + if ((png_ptr->transformations & PNG_EXPAND_16) != 0)
|
| + png_do_expand_16(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
|
| + /* NOTE: moved here in 1.5.4 (from much later in this list.) */
|
| + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) != 0 &&
|
| + (png_ptr->mode & PNG_BACKGROUND_IS_GRAY) != 0)
|
| + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_INVERT_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_INVERT_MONO) != 0)
|
| + png_do_invert(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_INVERT_ALPHA) != 0)
|
| + png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_SHIFT_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_SHIFT) != 0)
|
| + png_do_unshift(row_info, png_ptr->row_buf + 1,
|
| + &(png_ptr->shift));
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_PACK_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_PACK) != 0)
|
| + png_do_unpack(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
|
| + /* Added at libpng-1.5.10 */
|
| + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
|
| + png_ptr->num_palette_max >= 0)
|
| + png_do_check_palette_indexes(png_ptr, row_info);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_BGR_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_BGR) != 0)
|
| + png_do_bgr(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_PACKSWAP_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_PACKSWAP) != 0)
|
| + png_do_packswap(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_FILLER_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_FILLER) != 0)
|
| + png_do_read_filler(row_info, png_ptr->row_buf + 1,
|
| + (png_uint_32)png_ptr->filler, png_ptr->flags);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_SWAP_ALPHA) != 0)
|
| + png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_16BIT_SUPPORTED
|
| +#ifdef PNG_READ_SWAP_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_SWAP_BYTES) != 0)
|
| + png_do_swap(row_info, png_ptr->row_buf + 1);
|
| +#endif
|
| +#endif
|
| +
|
| +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
|
| + if ((png_ptr->transformations & PNG_USER_TRANSFORM) != 0)
|
| + {
|
| + if (png_ptr->read_user_transform_fn != NULL)
|
| + (*(png_ptr->read_user_transform_fn)) /* User read transform function */
|
| + (png_ptr, /* png_ptr */
|
| + row_info, /* row_info: */
|
| + /* png_uint_32 width; width of row */
|
| + /* png_size_t rowbytes; number of bytes in row */
|
| + /* png_byte color_type; color type of pixels */
|
| + /* png_byte bit_depth; bit depth of samples */
|
| + /* png_byte channels; number of channels (1-4) */
|
| + /* png_byte pixel_depth; bits per pixel (depth*channels) */
|
| + png_ptr->row_buf + 1); /* start of pixel data for row */
|
| +#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
|
| + if (png_ptr->user_transform_depth != 0)
|
| + row_info->bit_depth = png_ptr->user_transform_depth;
|
| +
|
| + if (png_ptr->user_transform_channels != 0)
|
| + row_info->channels = png_ptr->user_transform_channels;
|
| +#endif
|
| + row_info->pixel_depth = (png_byte)(row_info->bit_depth *
|
| + row_info->channels);
|
| +
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width);
|
| + }
|
| +#endif
|
| +}
|
| +
|
| +#endif /* READ_TRANSFORMS */
|
| +#endif /* READ */
|
|
|
Chromium Code Reviews
Issue 2033063003:
Check libpng directly into third_party/ (Closed)
Base URL: https://skia.googlesource.com/skia.git@master