Index: jquant1.c |
diff --git a/jquant1.c b/jquant1.c |
index aa2c59a4be82fe181f7737c0baacc13ab9632b8d..e7814815efe89733de962bde2be87ef573d1acea 100644 |
--- a/jquant1.c |
+++ b/jquant1.c |
@@ -4,8 +4,9 @@ |
* This file was part of the Independent JPEG Group's software: |
* Copyright (C) 1991-1996, Thomas G. Lane. |
* libjpeg-turbo Modifications: |
- * Copyright (C) 2009, D. R. Commander |
- * For conditions of distribution and use, see the accompanying README file. |
+ * Copyright (C) 2009, 2015, D. R. Commander. |
+ * For conditions of distribution and use, see the accompanying README.ijg |
+ * file. |
* |
* This file contains 1-pass color quantization (color mapping) routines. |
* These routines provide mapping to a fixed color map using equally spaced |
@@ -70,9 +71,9 @@ |
* table in both directions. |
*/ |
-#define ODITHER_SIZE 16 /* dimension of dither matrix */ |
+#define ODITHER_SIZE 16 /* dimension of dither matrix */ |
/* NB: if ODITHER_SIZE is not a power of 2, ODITHER_MASK uses will break */ |
-#define ODITHER_CELLS (ODITHER_SIZE*ODITHER_SIZE) /* # cells in matrix */ |
+#define ODITHER_CELLS (ODITHER_SIZE*ODITHER_SIZE) /* # cells in matrix */ |
#define ODITHER_MASK (ODITHER_SIZE-1) /* mask for wrapping around counters */ |
typedef int ODITHER_MATRIX[ODITHER_SIZE][ODITHER_SIZE]; |
@@ -107,8 +108,8 @@ static const UINT8 base_dither_matrix[ODITHER_SIZE][ODITHER_SIZE] = { |
* Errors are accumulated into the array fserrors[], at a resolution of |
* 1/16th of a pixel count. The error at a given pixel is propagated |
* to its not-yet-processed neighbors using the standard F-S fractions, |
- * ... (here) 7/16 |
- * 3/16 5/16 1/16 |
+ * ... (here) 7/16 |
+ * 3/16 5/16 1/16 |
* We work left-to-right on even rows, right-to-left on odd rows. |
* |
* We can get away with a single array (holding one row's worth of errors) |
@@ -121,52 +122,49 @@ static const UINT8 base_dither_matrix[ODITHER_SIZE][ODITHER_SIZE] = { |
* The fserrors[] array is indexed [component#][position]. |
* We provide (#columns + 2) entries per component; the extra entry at each |
* end saves us from special-casing the first and last pixels. |
- * |
- * Note: on a wide image, we might not have enough room in a PC's near data |
- * segment to hold the error array; so it is allocated with alloc_large. |
*/ |
#if BITS_IN_JSAMPLE == 8 |
-typedef INT16 FSERROR; /* 16 bits should be enough */ |
-typedef int LOCFSERROR; /* use 'int' for calculation temps */ |
+typedef INT16 FSERROR; /* 16 bits should be enough */ |
+typedef int LOCFSERROR; /* use 'int' for calculation temps */ |
#else |
-typedef INT32 FSERROR; /* may need more than 16 bits */ |
-typedef INT32 LOCFSERROR; /* be sure calculation temps are big enough */ |
+typedef JLONG FSERROR; /* may need more than 16 bits */ |
+typedef JLONG LOCFSERROR; /* be sure calculation temps are big enough */ |
#endif |
-typedef FSERROR FAR *FSERRPTR; /* pointer to error array (in FAR storage!) */ |
+typedef FSERROR *FSERRPTR; /* pointer to error array */ |
/* Private subobject */ |
-#define MAX_Q_COMPS 4 /* max components I can handle */ |
+#define MAX_Q_COMPS 4 /* max components I can handle */ |
typedef struct { |
struct jpeg_color_quantizer pub; /* public fields */ |
/* Initially allocated colormap is saved here */ |
- JSAMPARRAY sv_colormap; /* The color map as a 2-D pixel array */ |
- int sv_actual; /* number of entries in use */ |
+ JSAMPARRAY sv_colormap; /* The color map as a 2-D pixel array */ |
+ int sv_actual; /* number of entries in use */ |
- JSAMPARRAY colorindex; /* Precomputed mapping for speed */ |
+ JSAMPARRAY colorindex; /* Precomputed mapping for speed */ |
/* colorindex[i][j] = index of color closest to pixel value j in component i, |
* premultiplied as described above. Since colormap indexes must fit into |
* JSAMPLEs, the entries of this array will too. |
*/ |
- boolean is_padded; /* is the colorindex padded for odither? */ |
+ boolean is_padded; /* is the colorindex padded for odither? */ |
- int Ncolors[MAX_Q_COMPS]; /* # of values alloced to each component */ |
+ int Ncolors[MAX_Q_COMPS]; /* # of values alloced to each component */ |
/* Variables for ordered dithering */ |
- int row_index; /* cur row's vertical index in dither matrix */ |
+ int row_index; /* cur row's vertical index in dither matrix */ |
ODITHER_MATRIX_PTR odither[MAX_Q_COMPS]; /* one dither array per component */ |
/* Variables for Floyd-Steinberg dithering */ |
FSERRPTR fserrors[MAX_Q_COMPS]; /* accumulated errors */ |
- boolean on_odd_row; /* flag to remember which row we are on */ |
+ boolean on_odd_row; /* flag to remember which row we are on */ |
} my_cquantizer; |
-typedef my_cquantizer * my_cquantize_ptr; |
+typedef my_cquantizer *my_cquantize_ptr; |
/* |
@@ -205,11 +203,11 @@ select_ncolors (j_decompress_ptr cinfo, int Ncolors[]) |
iroot = 1; |
do { |
iroot++; |
- temp = iroot; /* set temp = iroot ** nc */ |
+ temp = iroot; /* set temp = iroot ** nc */ |
for (i = 1; i < nc; i++) |
temp *= iroot; |
} while (temp <= (long) max_colors); /* repeat till iroot exceeds root */ |
- iroot--; /* now iroot = floor(root) */ |
+ iroot--; /* now iroot = floor(root) */ |
/* Must have at least 2 color values per component */ |
if (iroot < 2) |
@@ -233,10 +231,10 @@ select_ncolors (j_decompress_ptr cinfo, int Ncolors[]) |
j = (cinfo->out_color_space == JCS_RGB ? RGB_order[i] : i); |
/* calculate new total_colors if Ncolors[j] is incremented */ |
temp = total_colors / Ncolors[j]; |
- temp *= Ncolors[j]+1; /* done in long arith to avoid oflo */ |
+ temp *= Ncolors[j]+1; /* done in long arith to avoid oflo */ |
if (temp > (long) max_colors) |
- break; /* won't fit, done with this pass */ |
- Ncolors[j]++; /* OK, apply the increment */ |
+ break; /* won't fit, done with this pass */ |
+ Ncolors[j]++; /* OK, apply the increment */ |
total_colors = (int) temp; |
changed = TRUE; |
} |
@@ -256,7 +254,7 @@ output_value (j_decompress_ptr cinfo, int ci, int j, int maxj) |
* (Forcing the upper and lower values to the limits ensures that |
* dithering can't produce a color outside the selected gamut.) |
*/ |
- return (int) (((INT32) j * MAXJSAMPLE + maxj/2) / maxj); |
+ return (int) (((JLONG) j * MAXJSAMPLE + maxj/2) / maxj); |
} |
@@ -266,7 +264,7 @@ largest_input_value (j_decompress_ptr cinfo, int ci, int j, int maxj) |
/* Must have largest(j=0) >= 0, and largest(j=maxj) >= MAXJSAMPLE */ |
{ |
/* Breakpoints are halfway between values returned by output_value */ |
- return (int) (((INT32) (2*j + 1) * MAXJSAMPLE + maxj) / (2*maxj)); |
+ return (int) (((JLONG) (2*j + 1) * MAXJSAMPLE + maxj) / (2*maxj)); |
} |
@@ -278,8 +276,8 @@ LOCAL(void) |
create_colormap (j_decompress_ptr cinfo) |
{ |
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
- JSAMPARRAY colormap; /* Created colormap */ |
- int total_colors; /* Number of distinct output colors */ |
+ JSAMPARRAY colormap; /* Created colormap */ |
+ int total_colors; /* Number of distinct output colors */ |
int i,j,k, nci, blksize, blkdist, ptr, val; |
/* Select number of colors for each component */ |
@@ -288,8 +286,8 @@ create_colormap (j_decompress_ptr cinfo) |
/* Report selected color counts */ |
if (cinfo->out_color_components == 3) |
TRACEMS4(cinfo, 1, JTRC_QUANT_3_NCOLORS, |
- total_colors, cquantize->Ncolors[0], |
- cquantize->Ncolors[1], cquantize->Ncolors[2]); |
+ total_colors, cquantize->Ncolors[0], |
+ cquantize->Ncolors[1], cquantize->Ncolors[2]); |
else |
TRACEMS1(cinfo, 1, JTRC_QUANT_NCOLORS, total_colors); |
@@ -314,12 +312,12 @@ create_colormap (j_decompress_ptr cinfo) |
val = output_value(cinfo, i, j, nci-1); |
/* Fill in all colormap entries that have this value of this component */ |
for (ptr = j * blksize; ptr < total_colors; ptr += blkdist) { |
- /* fill in blksize entries beginning at ptr */ |
- for (k = 0; k < blksize; k++) |
- colormap[i][ptr+k] = (JSAMPLE) val; |
+ /* fill in blksize entries beginning at ptr */ |
+ for (k = 0; k < blksize; k++) |
+ colormap[i][ptr+k] = (JSAMPLE) val; |
} |
} |
- blkdist = blksize; /* blksize of this color is blkdist of next */ |
+ blkdist = blksize; /* blksize of this color is blkdist of next */ |
} |
/* Save the colormap in private storage, |
@@ -377,16 +375,16 @@ create_colorindex (j_decompress_ptr cinfo) |
val = 0; |
k = largest_input_value(cinfo, i, 0, nci-1); |
for (j = 0; j <= MAXJSAMPLE; j++) { |
- while (j > k) /* advance val if past boundary */ |
- k = largest_input_value(cinfo, i, ++val, nci-1); |
+ while (j > k) /* advance val if past boundary */ |
+ k = largest_input_value(cinfo, i, ++val, nci-1); |
/* premultiply so that no multiplication needed in main processing */ |
indexptr[j] = (JSAMPLE) (val * blksize); |
} |
/* Pad at both ends if necessary */ |
if (pad) |
for (j = 1; j <= MAXJSAMPLE; j++) { |
- indexptr[-j] = indexptr[0]; |
- indexptr[MAXJSAMPLE+j] = indexptr[MAXJSAMPLE]; |
+ indexptr[-j] = indexptr[0]; |
+ indexptr[MAXJSAMPLE+j] = indexptr[MAXJSAMPLE]; |
} |
} |
} |
@@ -402,21 +400,21 @@ make_odither_array (j_decompress_ptr cinfo, int ncolors) |
{ |
ODITHER_MATRIX_PTR odither; |
int j,k; |
- INT32 num,den; |
+ JLONG num,den; |
odither = (ODITHER_MATRIX_PTR) |
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
- SIZEOF(ODITHER_MATRIX)); |
+ sizeof(ODITHER_MATRIX)); |
/* The inter-value distance for this color is MAXJSAMPLE/(ncolors-1). |
* Hence the dither value for the matrix cell with fill order f |
* (f=0..N-1) should be (N-1-2*f)/(2*N) * MAXJSAMPLE/(ncolors-1). |
* On 16-bit-int machine, be careful to avoid overflow. |
*/ |
- den = 2 * ODITHER_CELLS * ((INT32) (ncolors - 1)); |
+ den = 2 * ODITHER_CELLS * ((JLONG) (ncolors - 1)); |
for (j = 0; j < ODITHER_SIZE; j++) { |
for (k = 0; k < ODITHER_SIZE; k++) { |
- num = ((INT32) (ODITHER_CELLS-1 - 2*((int)base_dither_matrix[j][k]))) |
- * MAXJSAMPLE; |
+ num = ((JLONG) (ODITHER_CELLS-1 - 2*((int)base_dither_matrix[j][k]))) |
+ * MAXJSAMPLE; |
/* Ensure round towards zero despite C's lack of consistency |
* about rounding negative values in integer division... |
*/ |
@@ -429,7 +427,7 @@ make_odither_array (j_decompress_ptr cinfo, int ncolors) |
/* |
* Create the ordered-dither tables. |
- * Components having the same number of representative colors may |
+ * Components having the same number of representative colors may |
* share a dither table. |
*/ |
@@ -442,14 +440,14 @@ create_odither_tables (j_decompress_ptr cinfo) |
for (i = 0; i < cinfo->out_color_components; i++) { |
nci = cquantize->Ncolors[i]; /* # of distinct values for this color */ |
- odither = NULL; /* search for matching prior component */ |
+ odither = NULL; /* search for matching prior component */ |
for (j = 0; j < i; j++) { |
if (nci == cquantize->Ncolors[j]) { |
- odither = cquantize->odither[j]; |
- break; |
+ odither = cquantize->odither[j]; |
+ break; |
} |
} |
- if (odither == NULL) /* need a new table? */ |
+ if (odither == NULL) /* need a new table? */ |
odither = make_odither_array(cinfo, nci); |
cquantize->odither[i] = odither; |
} |
@@ -462,7 +460,7 @@ create_odither_tables (j_decompress_ptr cinfo) |
METHODDEF(void) |
color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
- JSAMPARRAY output_buf, int num_rows) |
+ JSAMPARRAY output_buf, int num_rows) |
/* General case, no dithering */ |
{ |
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
@@ -480,7 +478,7 @@ color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
for (col = width; col > 0; col--) { |
pixcode = 0; |
for (ci = 0; ci < nc; ci++) { |
- pixcode += GETJSAMPLE(colorindex[ci][GETJSAMPLE(*ptrin++)]); |
+ pixcode += GETJSAMPLE(colorindex[ci][GETJSAMPLE(*ptrin++)]); |
} |
*ptrout++ = (JSAMPLE) pixcode; |
} |
@@ -490,7 +488,7 @@ color_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
METHODDEF(void) |
color_quantize3 (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
- JSAMPARRAY output_buf, int num_rows) |
+ JSAMPARRAY output_buf, int num_rows) |
/* Fast path for out_color_components==3, no dithering */ |
{ |
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
@@ -518,15 +516,15 @@ color_quantize3 (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
METHODDEF(void) |
quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
- JSAMPARRAY output_buf, int num_rows) |
+ JSAMPARRAY output_buf, int num_rows) |
/* General case, with ordered dithering */ |
{ |
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
register JSAMPROW input_ptr; |
register JSAMPROW output_ptr; |
JSAMPROW colorindex_ci; |
- int * dither; /* points to active row of dither matrix */ |
- int row_index, col_index; /* current indexes into dither matrix */ |
+ int *dither; /* points to active row of dither matrix */ |
+ int row_index, col_index; /* current indexes into dither matrix */ |
int nc = cinfo->out_color_components; |
int ci; |
int row; |
@@ -535,8 +533,7 @@ quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
for (row = 0; row < num_rows; row++) { |
/* Initialize output values to 0 so can process components separately */ |
- jzero_far((void FAR *) output_buf[row], |
- (size_t) (width * SIZEOF(JSAMPLE))); |
+ jzero_far((void *) output_buf[row], (size_t) (width * sizeof(JSAMPLE))); |
row_index = cquantize->row_index; |
for (ci = 0; ci < nc; ci++) { |
input_ptr = input_buf[row] + ci; |
@@ -546,17 +543,17 @@ quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
col_index = 0; |
for (col = width; col > 0; col--) { |
- /* Form pixel value + dither, range-limit to 0..MAXJSAMPLE, |
- * select output value, accumulate into output code for this pixel. |
- * Range-limiting need not be done explicitly, as we have extended |
- * the colorindex table to produce the right answers for out-of-range |
- * inputs. The maximum dither is +- MAXJSAMPLE; this sets the |
- * required amount of padding. |
- */ |
- *output_ptr += colorindex_ci[GETJSAMPLE(*input_ptr)+dither[col_index]]; |
- input_ptr += nc; |
- output_ptr++; |
- col_index = (col_index + 1) & ODITHER_MASK; |
+ /* Form pixel value + dither, range-limit to 0..MAXJSAMPLE, |
+ * select output value, accumulate into output code for this pixel. |
+ * Range-limiting need not be done explicitly, as we have extended |
+ * the colorindex table to produce the right answers for out-of-range |
+ * inputs. The maximum dither is +- MAXJSAMPLE; this sets the |
+ * required amount of padding. |
+ */ |
+ *output_ptr += colorindex_ci[GETJSAMPLE(*input_ptr)+dither[col_index]]; |
+ input_ptr += nc; |
+ output_ptr++; |
+ col_index = (col_index + 1) & ODITHER_MASK; |
} |
} |
/* Advance row index for next row */ |
@@ -568,7 +565,7 @@ quantize_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
METHODDEF(void) |
quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
- JSAMPARRAY output_buf, int num_rows) |
+ JSAMPARRAY output_buf, int num_rows) |
/* Fast path for out_color_components==3, with ordered dithering */ |
{ |
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
@@ -578,10 +575,10 @@ quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
JSAMPROW colorindex0 = cquantize->colorindex[0]; |
JSAMPROW colorindex1 = cquantize->colorindex[1]; |
JSAMPROW colorindex2 = cquantize->colorindex[2]; |
- int * dither0; /* points to active row of dither matrix */ |
- int * dither1; |
- int * dither2; |
- int row_index, col_index; /* current indexes into dither matrix */ |
+ int *dither0; /* points to active row of dither matrix */ |
+ int *dither1; |
+ int *dither2; |
+ int row_index, col_index; /* current indexes into dither matrix */ |
int row; |
JDIMENSION col; |
JDIMENSION width = cinfo->output_width; |
@@ -597,11 +594,11 @@ quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
for (col = width; col > 0; col--) { |
pixcode = GETJSAMPLE(colorindex0[GETJSAMPLE(*input_ptr++) + |
- dither0[col_index]]); |
+ dither0[col_index]]); |
pixcode += GETJSAMPLE(colorindex1[GETJSAMPLE(*input_ptr++) + |
- dither1[col_index]]); |
+ dither1[col_index]]); |
pixcode += GETJSAMPLE(colorindex2[GETJSAMPLE(*input_ptr++) + |
- dither2[col_index]]); |
+ dither2[col_index]]); |
*output_ptr++ = (JSAMPLE) pixcode; |
col_index = (col_index + 1) & ODITHER_MASK; |
} |
@@ -613,24 +610,24 @@ quantize3_ord_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
METHODDEF(void) |
quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
- JSAMPARRAY output_buf, int num_rows) |
+ JSAMPARRAY output_buf, int num_rows) |
/* General case, with Floyd-Steinberg dithering */ |
{ |
my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
- register LOCFSERROR cur; /* current error or pixel value */ |
- LOCFSERROR belowerr; /* error for pixel below cur */ |
- LOCFSERROR bpreverr; /* error for below/prev col */ |
- LOCFSERROR bnexterr; /* error for below/next col */ |
+ register LOCFSERROR cur; /* current error or pixel value */ |
+ LOCFSERROR belowerr; /* error for pixel below cur */ |
+ LOCFSERROR bpreverr; /* error for below/prev col */ |
+ LOCFSERROR bnexterr; /* error for below/next col */ |
LOCFSERROR delta; |
- register FSERRPTR errorptr; /* => fserrors[] at column before current */ |
+ register FSERRPTR errorptr; /* => fserrors[] at column before current */ |
register JSAMPROW input_ptr; |
register JSAMPROW output_ptr; |
JSAMPROW colorindex_ci; |
JSAMPROW colormap_ci; |
int pixcode; |
int nc = cinfo->out_color_components; |
- int dir; /* 1 for left-to-right, -1 for right-to-left */ |
- int dirnc; /* dir * nc */ |
+ int dir; /* 1 for left-to-right, -1 for right-to-left */ |
+ int dirnc; /* dir * nc */ |
int ci; |
int row; |
JDIMENSION col; |
@@ -640,23 +637,22 @@ quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
for (row = 0; row < num_rows; row++) { |
/* Initialize output values to 0 so can process components separately */ |
- jzero_far((void FAR *) output_buf[row], |
- (size_t) (width * SIZEOF(JSAMPLE))); |
+ jzero_far((void *) output_buf[row], (size_t) (width * sizeof(JSAMPLE))); |
for (ci = 0; ci < nc; ci++) { |
input_ptr = input_buf[row] + ci; |
output_ptr = output_buf[row]; |
if (cquantize->on_odd_row) { |
- /* work right to left in this row */ |
- input_ptr += (width-1) * nc; /* so point to rightmost pixel */ |
- output_ptr += width-1; |
- dir = -1; |
- dirnc = -nc; |
- errorptr = cquantize->fserrors[ci] + (width+1); /* => entry after last column */ |
+ /* work right to left in this row */ |
+ input_ptr += (width-1) * nc; /* so point to rightmost pixel */ |
+ output_ptr += width-1; |
+ dir = -1; |
+ dirnc = -nc; |
+ errorptr = cquantize->fserrors[ci] + (width+1); /* => entry after last column */ |
} else { |
- /* work left to right in this row */ |
- dir = 1; |
- dirnc = nc; |
- errorptr = cquantize->fserrors[ci]; /* => entry before first column */ |
+ /* work left to right in this row */ |
+ dir = 1; |
+ dirnc = nc; |
+ errorptr = cquantize->fserrors[ci]; /* => entry before first column */ |
} |
colorindex_ci = cquantize->colorindex[ci]; |
colormap_ci = cquantize->sv_colormap[ci]; |
@@ -666,47 +662,47 @@ quantize_fs_dither (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
belowerr = bpreverr = 0; |
for (col = width; col > 0; col--) { |
- /* cur holds the error propagated from the previous pixel on the |
- * current line. Add the error propagated from the previous line |
- * to form the complete error correction term for this pixel, and |
- * round the error term (which is expressed * 16) to an integer. |
- * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct |
- * for either sign of the error value. |
- * Note: errorptr points to *previous* column's array entry. |
- */ |
- cur = RIGHT_SHIFT(cur + errorptr[dir] + 8, 4); |
- /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE. |
- * The maximum error is +- MAXJSAMPLE; this sets the required size |
- * of the range_limit array. |
- */ |
- cur += GETJSAMPLE(*input_ptr); |
- cur = GETJSAMPLE(range_limit[cur]); |
- /* Select output value, accumulate into output code for this pixel */ |
- pixcode = GETJSAMPLE(colorindex_ci[cur]); |
- *output_ptr += (JSAMPLE) pixcode; |
- /* Compute actual representation error at this pixel */ |
- /* Note: we can do this even though we don't have the final */ |
- /* pixel code, because the colormap is orthogonal. */ |
- cur -= GETJSAMPLE(colormap_ci[pixcode]); |
- /* Compute error fractions to be propagated to adjacent pixels. |
- * Add these into the running sums, and simultaneously shift the |
- * next-line error sums left by 1 column. |
- */ |
- bnexterr = cur; |
- delta = cur * 2; |
- cur += delta; /* form error * 3 */ |
- errorptr[0] = (FSERROR) (bpreverr + cur); |
- cur += delta; /* form error * 5 */ |
- bpreverr = belowerr + cur; |
- belowerr = bnexterr; |
- cur += delta; /* form error * 7 */ |
- /* At this point cur contains the 7/16 error value to be propagated |
- * to the next pixel on the current line, and all the errors for the |
- * next line have been shifted over. We are therefore ready to move on. |
- */ |
- input_ptr += dirnc; /* advance input ptr to next column */ |
- output_ptr += dir; /* advance output ptr to next column */ |
- errorptr += dir; /* advance errorptr to current column */ |
+ /* cur holds the error propagated from the previous pixel on the |
+ * current line. Add the error propagated from the previous line |
+ * to form the complete error correction term for this pixel, and |
+ * round the error term (which is expressed * 16) to an integer. |
+ * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct |
+ * for either sign of the error value. |
+ * Note: errorptr points to *previous* column's array entry. |
+ */ |
+ cur = RIGHT_SHIFT(cur + errorptr[dir] + 8, 4); |
+ /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE. |
+ * The maximum error is +- MAXJSAMPLE; this sets the required size |
+ * of the range_limit array. |
+ */ |
+ cur += GETJSAMPLE(*input_ptr); |
+ cur = GETJSAMPLE(range_limit[cur]); |
+ /* Select output value, accumulate into output code for this pixel */ |
+ pixcode = GETJSAMPLE(colorindex_ci[cur]); |
+ *output_ptr += (JSAMPLE) pixcode; |
+ /* Compute actual representation error at this pixel */ |
+ /* Note: we can do this even though we don't have the final */ |
+ /* pixel code, because the colormap is orthogonal. */ |
+ cur -= GETJSAMPLE(colormap_ci[pixcode]); |
+ /* Compute error fractions to be propagated to adjacent pixels. |
+ * Add these into the running sums, and simultaneously shift the |
+ * next-line error sums left by 1 column. |
+ */ |
+ bnexterr = cur; |
+ delta = cur * 2; |
+ cur += delta; /* form error * 3 */ |
+ errorptr[0] = (FSERROR) (bpreverr + cur); |
+ cur += delta; /* form error * 5 */ |
+ bpreverr = belowerr + cur; |
+ belowerr = bnexterr; |
+ cur += delta; /* form error * 7 */ |
+ /* At this point cur contains the 7/16 error value to be propagated |
+ * to the next pixel on the current line, and all the errors for the |
+ * next line have been shifted over. We are therefore ready to move on. |
+ */ |
+ input_ptr += dirnc; /* advance input ptr to next column */ |
+ output_ptr += dir; /* advance output ptr to next column */ |
+ errorptr += dir; /* advance errorptr to current column */ |
} |
/* Post-loop cleanup: we must unload the final error value into the |
* final fserrors[] entry. Note we need not unload belowerr because |
@@ -730,7 +726,7 @@ alloc_fs_workspace (j_decompress_ptr cinfo) |
size_t arraysize; |
int i; |
- arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR)); |
+ arraysize = (size_t) ((cinfo->output_width + 2) * sizeof(FSERROR)); |
for (i = 0; i < cinfo->out_color_components; i++) { |
cquantize->fserrors[i] = (FSERRPTR) |
(*cinfo->mem->alloc_large)((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize); |
@@ -766,7 +762,7 @@ start_pass_1_quant (j_decompress_ptr cinfo, boolean is_pre_scan) |
cquantize->pub.color_quantize = quantize3_ord_dither; |
else |
cquantize->pub.color_quantize = quantize_ord_dither; |
- cquantize->row_index = 0; /* initialize state for ordered dither */ |
+ cquantize->row_index = 0; /* initialize state for ordered dither */ |
/* If user changed to ordered dither from another mode, |
* we must recreate the color index table with padding. |
* This will cost extra space, but probably isn't very likely. |
@@ -784,9 +780,9 @@ start_pass_1_quant (j_decompress_ptr cinfo, boolean is_pre_scan) |
if (cquantize->fserrors[0] == NULL) |
alloc_fs_workspace(cinfo); |
/* Initialize the propagated errors to zero. */ |
- arraysize = (size_t) ((cinfo->output_width + 2) * SIZEOF(FSERROR)); |
+ arraysize = (size_t) ((cinfo->output_width + 2) * sizeof(FSERROR)); |
for (i = 0; i < cinfo->out_color_components; i++) |
- jzero_far((void FAR *) cquantize->fserrors[i], arraysize); |
+ jzero_far((void *) cquantize->fserrors[i], arraysize); |
break; |
default: |
ERREXIT(cinfo, JERR_NOT_COMPILED); |
@@ -829,13 +825,13 @@ jinit_1pass_quantizer (j_decompress_ptr cinfo) |
cquantize = (my_cquantize_ptr) |
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
- SIZEOF(my_cquantizer)); |
+ sizeof(my_cquantizer)); |
cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize; |
cquantize->pub.start_pass = start_pass_1_quant; |
cquantize->pub.finish_pass = finish_pass_1_quant; |
cquantize->pub.new_color_map = new_color_map_1_quant; |
cquantize->fserrors[0] = NULL; /* Flag FS workspace not allocated */ |
- cquantize->odither[0] = NULL; /* Also flag odither arrays not allocated */ |
+ cquantize->odither[0] = NULL; /* Also flag odither arrays not allocated */ |
/* Make sure my internal arrays won't overflow */ |
if (cinfo->out_color_components > MAX_Q_COMPS) |
@@ -849,10 +845,10 @@ jinit_1pass_quantizer (j_decompress_ptr cinfo) |
create_colorindex(cinfo); |
/* Allocate Floyd-Steinberg workspace now if requested. |
- * We do this now since it is FAR storage and may affect the memory |
- * manager's space calculations. If the user changes to FS dither |
- * mode in a later pass, we will allocate the space then, and will |
- * possibly overrun the max_memory_to_use setting. |
+ * We do this now since it may affect the memory manager's space |
+ * calculations. If the user changes to FS dither mode in a later pass, we |
+ * will allocate the space then, and will possibly overrun the |
+ * max_memory_to_use setting. |
*/ |
if (cinfo->dither_mode == JDITHER_FS) |
alloc_fs_workspace(cinfo); |