2764 lines
88 KiB
C
2764 lines
88 KiB
C
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/* pngrtran.c - transforms the data in a row for png readers
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libpng 1.0 beta 2 - version 0.8
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For conditions of distribution and use, see copyright notice in png.h
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Copyright (c) 1995 Guy Eric Schalnat, Group 42, Inc.
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August 20, 1995
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*/
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#define PNG_INTERNAL
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#include "png.h"
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#if defined(PNG_READ_BACKGROUND_SUPPORTED)
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/* handle alpha and tRNS via a background color */
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void
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png_set_background(png_struct *png_ptr,
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png_color_16 *background_color, int background_gamma_code,
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int need_expand, double background_gamma)
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{
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png_ptr->transformations |= PNG_BACKGROUND;
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png_memcpy(&(png_ptr->background), background_color,
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sizeof(png_color_16));
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png_ptr->background_gamma = (float)background_gamma;
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png_ptr->background_gamma_type = background_gamma_code;
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png_ptr->background_expand = need_expand;
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}
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#endif
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#if defined(PNG_READ_16_TO_8_SUPPORTED)
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/* strip 16 bit depth files to 8 bit depth */
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void
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png_set_strip_16(png_struct *png_ptr)
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{
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png_ptr->transformations |= PNG_16_TO_8;
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}
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#endif
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#if defined(PNG_READ_DITHER_SUPPORTED)
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/* dither file to 8 bit. Supply a palette, the current number
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of elements in the palette, the maximum number of elements
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allowed, and a histogram, if possible. If the current number
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is greater then the maximum number, the palette will be
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modified to fit in the maximum number */
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typedef struct dsort_struct
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{
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struct dsort_struct *next;
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png_byte left;
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png_byte right;
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} dsort;
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void
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png_set_dither(png_struct *png_ptr, png_color *palette,
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int num_palette, int maximum_colors, png_uint_16 *histogram,
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int full_dither)
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{
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png_ptr->transformations |= PNG_DITHER;
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if (!full_dither)
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{
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int i;
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png_ptr->dither_index = png_malloc(png_ptr,
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num_palette * sizeof (png_byte));
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for (i = 0; i < num_palette; i++)
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png_ptr->dither_index[i] = i;
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}
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if (num_palette > maximum_colors)
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{
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if (histogram)
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{
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/* this is easy enough, just throw out the least used colors.
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perhaps not the best solution, but good enough */
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int i;
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png_byte *sort;
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/* initialize an array to sort colors */
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sort = (png_byte *)png_malloc(png_ptr, num_palette * sizeof (png_byte));
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/* initialize the sort array */
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for (i = 0; i < num_palette; i++)
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sort[i] = i;
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/* find the least used palette entries by starting a
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bubble sort, and running it until we have sorted
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out enough colors. Note that we don't care about
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sorting all the colors, just finding which are
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least used. */
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for (i = num_palette - 1; i >= maximum_colors; i--)
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{
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int done; /* to stop early if the list is pre-sorted */
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int j;
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done = 1;
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for (j = 0; j < i; j++)
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{
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if (histogram[sort[j]] < histogram[sort[j + 1]])
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{
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png_byte t;
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t = sort[j];
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sort[j] = sort[j + 1];
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sort[j + 1] = t;
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done = 0;
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}
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}
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if (done)
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break;
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}
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/* swap the palette around, and set up a table, if necessary */
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if (full_dither)
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{
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int j;
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/* put all the useful colors within the max, but don't
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move the others */
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j = num_palette;
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for (i = 0; i < maximum_colors; i++)
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{
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if (sort[i] >= maximum_colors)
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{
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do
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j--;
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while (sort[j] >= maximum_colors);
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palette[i] = palette[j];
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}
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}
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}
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else
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{
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int j;
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/* move all the used colors inside the max limit, and
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develop a translation table */
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j = num_palette;
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for (i = 0; i < maximum_colors; i++)
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{
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/* only move the colors we need to */
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if (sort[i] >= maximum_colors)
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{
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png_color tmp_color;
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do
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j--;
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while (sort[j] >= maximum_colors);
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tmp_color = palette[j];
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palette[j] = palette[i];
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palette[i] = tmp_color;
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/* indicate where the color went */
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png_ptr->dither_index[j] = i;
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png_ptr->dither_index[i] = j;
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}
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}
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/* find closest color for those colors we are not
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using */
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for (i = 0; i < num_palette; i++)
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{
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if (png_ptr->dither_index[i] >= maximum_colors)
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{
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int min_d, j, min_j, index;
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/* find the closest color to one we threw out */
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index = png_ptr->dither_index[i];
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min_d = PNG_COLOR_DIST(palette[index],
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palette[0]);
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min_j = 0;
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for (j = 1; j < maximum_colors; j++)
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{
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int d;
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d = PNG_COLOR_DIST(palette[index],
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palette[j]);
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if (d < min_d)
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{
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min_d = d;
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min_j = j;
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}
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}
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/* point to closest color */
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png_ptr->dither_index[i] = min_j;
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}
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}
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}
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png_free(png_ptr, sort);
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}
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else
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{
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/* this is much harder to do simply (and quickly). Perhaps
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we need to go through a median cut routine, but those
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don't always behave themselves with only a few colors
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as input. So we will just find the closest two colors,
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and throw out one of them (chosen somewhat randomly).
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*/
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int i;
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int max_d;
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int num_new_palette;
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dsort **hash;
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png_byte *index_to_palette;
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/* where the original index currently is in the palette */
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png_byte *palette_to_index;
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/* which original index points to this palette color */
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/* initialize palette index arrays */
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index_to_palette = (png_byte *)png_malloc(png_ptr,
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num_palette * sizeof (png_byte));
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palette_to_index = (png_byte *)png_malloc(png_ptr,
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num_palette * sizeof (png_byte));
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/* initialize the sort array */
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for (i = 0; i < num_palette; i++)
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{
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index_to_palette[i] = i;
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palette_to_index[i] = i;
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}
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hash = (dsort **)png_malloc(png_ptr, 769 * sizeof (dsort *));
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for (i = 0; i < 769; i++)
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hash[i] = (dsort *)0;
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/* png_memset(hash, 0, 769 * sizeof (dsort *)); */
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num_new_palette = num_palette;
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/* initial wild guess at how far apart the farthest pixel
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pair we will be eliminating will be. Larger
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numbers mean more areas will be allocated, Smaller
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numbers run the risk of not saving enough data, and
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having to do this all over again.
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I have not done extensive checking on this number.
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*/
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max_d = 96;
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while (num_new_palette > maximum_colors)
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{
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for (i = 0; i < num_new_palette - 1; i++)
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{
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int j;
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for (j = i + 1; j < num_new_palette; j++)
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{
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int d;
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d = PNG_COLOR_DIST(palette[i], palette[j]);
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if (d <= max_d)
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{
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dsort *t;
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t = png_malloc(png_ptr, sizeof (dsort));
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t->next = hash[d];
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t->left = i;
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t->right = j;
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hash[d] = t;
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}
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}
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}
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for (i = 0; i <= max_d; i++)
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{
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if (hash[i])
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{
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dsort *p;
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for (p = hash[i]; p; p = p->next)
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{
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if (index_to_palette[p->left] < num_new_palette &&
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index_to_palette[p->right] < num_new_palette)
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{
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int j, next_j;
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if (num_new_palette & 1)
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{
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j = p->left;
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next_j = p->right;
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}
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else
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{
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j = p->right;
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next_j = p->left;
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}
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num_new_palette--;
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palette[index_to_palette[j]] =
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palette[num_new_palette];
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if (!full_dither)
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{
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int k;
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for (k = 0; k < num_palette; k++)
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{
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if (png_ptr->dither_index[k] ==
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index_to_palette[j])
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png_ptr->dither_index[k] =
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index_to_palette[next_j];
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if (png_ptr->dither_index[k] ==
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num_new_palette)
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png_ptr->dither_index[k] =
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index_to_palette[j];
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}
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}
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index_to_palette[palette_to_index[num_new_palette]] =
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index_to_palette[j];
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palette_to_index[index_to_palette[j]] =
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palette_to_index[num_new_palette];
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index_to_palette[j] = num_new_palette;
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palette_to_index[num_new_palette] = j;
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}
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if (num_new_palette <= maximum_colors)
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break;
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}
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if (num_new_palette <= maximum_colors)
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break;
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}
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}
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for (i = 0; i < 769; i++)
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{
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if (hash[i])
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{
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dsort *p;
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p = hash[i];
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while (p)
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{
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dsort *t;
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t = p->next;
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png_free(png_ptr, p);
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p = t;
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}
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}
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hash[i] = 0;
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}
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max_d += 96;
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}
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png_free(png_ptr, hash);
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png_free(png_ptr, palette_to_index);
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png_free(png_ptr, index_to_palette);
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}
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num_palette = maximum_colors;
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}
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if (!(png_ptr->palette))
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{
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png_ptr->palette = palette;
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png_ptr->user_palette = 1;
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}
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png_ptr->num_palette = num_palette;
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if (full_dither)
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{
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int i;
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int total_bits, num_red, num_green, num_blue;
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png_uint_32 num_entries;
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png_bytef *distance;
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total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
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PNG_DITHER_BLUE_BITS;
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num_red = (1 << PNG_DITHER_RED_BITS);
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num_green = (1 << PNG_DITHER_GREEN_BITS);
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num_blue = (1 << PNG_DITHER_BLUE_BITS);
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num_entries = ((png_uint_32)1 << total_bits);
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png_ptr->palette_lookup = (png_bytef *)png_large_malloc(png_ptr,
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(png_size_t)num_entries * sizeof (png_byte));
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png_memset(png_ptr->palette_lookup, 0, (png_size_t)num_entries * sizeof (png_byte));
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distance = (png_bytef *)png_large_malloc(png_ptr,
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(png_size_t)num_entries * sizeof (png_byte));
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png_memset(distance, 0xff, (png_size_t)num_entries * sizeof (png_byte));
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for (i = 0; i < num_palette; i++)
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{
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int r, g, b, ir, ig, ib;
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r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
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g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
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b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));
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for (ir = 0; ir < num_red; ir++)
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{
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int dr, index_r;
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dr = abs(ir - r);
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index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS));
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for (ig = 0; ig < num_green; ig++)
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{
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int dg, dt, dm, index_g;
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dg = abs(ig - g);
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dt = dr + dg;
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dm = ((dr > dg) ? dr : dg);
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index_g = index_r | (ig << PNG_DITHER_BLUE_BITS);
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for (ib = 0; ib < num_blue; ib++)
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{
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int index, db, dmax, d;
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index = index_g | ib;
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db = abs(ib - b);
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dmax = ((dm > db) ? dm : db);
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d = dmax + dt + db;
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if (d < distance[index])
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{
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distance[index] = d;
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png_ptr->palette_lookup[index] = i;
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}
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}
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}
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}
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}
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png_large_free(png_ptr, distance);
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}
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}
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#endif
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#if defined(PNG_READ_GAMMA_SUPPORTED)
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/* transform the image from the file_gamma to the screen_gamma */
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void
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png_set_gamma(png_struct *png_ptr, double screen_gamma,
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double file_gamma)
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{
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png_ptr->transformations |= PNG_GAMMA;
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png_ptr->gamma = (float)file_gamma;
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png_ptr->display_gamma = (float)screen_gamma;
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}
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#endif
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#if defined(PNG_READ_EXPAND_SUPPORTED)
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/* expand paletted images to rgb, expand grayscale images of
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less then 8 bit depth to 8 bit depth, and expand tRNS chunks
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to alpha channels */
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void
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png_set_expand(png_struct *png_ptr)
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{
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png_ptr->transformations |= PNG_EXPAND;
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}
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#endif
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#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
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void
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png_set_gray_to_rgb(png_struct *png_ptr)
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{
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png_ptr->transformations |= PNG_GRAY_TO_RGB;
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}
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#endif
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/* initialize everything needed for the read. This includes modifying
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the palette */
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void
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png_init_read_transformations(png_struct *png_ptr)
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{
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int color_type;
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color_type = png_ptr->color_type;
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#if defined(PNG_READ_EXPAND_SUPPORTED) && \
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defined(PNG_READ_BACKGROUND_SUPPORTED)
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if (png_ptr->transformations & PNG_EXPAND)
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{
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if (color_type == PNG_COLOR_TYPE_GRAY &&
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png_ptr->bit_depth < 8 &&
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(png_ptr->transformations & PNG_BACKGROUND) &&
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png_ptr->background_expand)
|
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/* (!(png_ptr->transformations & PNG_BACKGROUND) ||
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png_ptr->background_expand)) */
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{
|
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/* expand background chunk. While this may not be
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the fastest way to do this, it only happens once
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per file. */
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switch (png_ptr->bit_depth)
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{
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case 1:
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png_ptr->background.gray *= 0xff;
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break;
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case 2:
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png_ptr->background.gray *= 0x55;
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break;
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case 4:
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png_ptr->background.gray *= 0x11;
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break;
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}
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}
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if (color_type == PNG_COLOR_TYPE_PALETTE &&
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(png_ptr->transformations & PNG_BACKGROUND) &&
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png_ptr->background_expand)
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{
|
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/* expand background chunk */
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png_ptr->background.red =
|
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png_ptr->palette[png_ptr->background.index].red;
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png_ptr->background.green =
|
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png_ptr->palette[png_ptr->background.index].green;
|
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png_ptr->background.blue =
|
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png_ptr->palette[png_ptr->background.index].blue;
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color_type = PNG_COLOR_TYPE_RGB;
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}
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}
|
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#endif
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|
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#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
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png_ptr->background_1 = png_ptr->background;
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#endif
|
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#if defined(PNG_READ_GAMMA_SUPPORTED)
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if (png_ptr->transformations & PNG_GAMMA)
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{
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png_build_gamma_table(png_ptr);
|
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#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
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if ((png_ptr->transformations & PNG_BACKGROUND) &&
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(color_type != PNG_COLOR_TYPE_PALETTE))
|
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{
|
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if (png_ptr->background_gamma_type != PNG_BACKGROUND_GAMMA_UNKNOWN)
|
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{
|
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double g, gs, m;
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|
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m = (double)((png_uint_32)1 << png_ptr->bit_depth);
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g = 1.0;
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gs = 1.0;
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|
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switch (png_ptr->background_gamma_type)
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{
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case PNG_BACKGROUND_GAMMA_SCREEN:
|
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g = (png_ptr->display_gamma);
|
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gs = 1.0;
|
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break;
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case PNG_BACKGROUND_GAMMA_FILE:
|
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g = 1.0 / (png_ptr->gamma);
|
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gs = 1.0 / (png_ptr->gamma * png_ptr->display_gamma);
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break;
|
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case PNG_BACKGROUND_GAMMA_UNIQUE:
|
|
g = 1.0 / (png_ptr->background_gamma);
|
|
gs = 1.0 / (png_ptr->background_gamma *
|
|
png_ptr->display_gamma);
|
|
break;
|
|
}
|
|
|
|
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
|
|
{
|
|
png_ptr->background_1.red = (png_uint_16)(pow(
|
|
(double)png_ptr->background.red / m, g) * m + .5);
|
|
png_ptr->background_1.green = (png_uint_16)(pow(
|
|
(double)png_ptr->background.green / m, g) * m + .5);
|
|
png_ptr->background_1.blue = (png_uint_16)(pow(
|
|
(double)png_ptr->background.blue / m, g) * m + .5);
|
|
png_ptr->background.red = (png_uint_16)(pow(
|
|
(double)png_ptr->background.red / m, gs) * m + .5);
|
|
png_ptr->background.green = (png_uint_16)(pow(
|
|
(double)png_ptr->background.green / m, gs) * m + .5);
|
|
png_ptr->background.blue = (png_uint_16)(pow(
|
|
(double)png_ptr->background.blue / m, gs) * m + .5);
|
|
}
|
|
else
|
|
{
|
|
png_ptr->background_1.gray = (png_uint_16)(pow(
|
|
(double)png_ptr->background.gray / m, g) * m + .5);
|
|
png_ptr->background.gray = (png_uint_16)(pow(
|
|
(double)png_ptr->background.gray / m, gs) * m + .5);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_SHIFT_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_SHIFT) &&
|
|
png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
png_uint_16 i;
|
|
int sr, sg, sb;
|
|
|
|
sr = 8 - png_ptr->sig_bit.red;
|
|
if (sr < 0 || sr > 8)
|
|
sr = 0;
|
|
sg = 8 - png_ptr->sig_bit.green;
|
|
if (sg < 0 || sg > 8)
|
|
sg = 0;
|
|
sb = 8 - png_ptr->sig_bit.blue;
|
|
if (sb < 0 || sb > 8)
|
|
sb = 0;
|
|
for (i = 0; i < png_ptr->num_palette; i++)
|
|
{
|
|
png_ptr->palette[i].red >>= sr;
|
|
png_ptr->palette[i].green >>= sg;
|
|
png_ptr->palette[i].blue >>= sb;
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/* 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
|
|
png_read_transform_info(png_struct *png_ptr, png_info *info_ptr)
|
|
{
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_EXPAND) &&
|
|
info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
if (png_ptr->num_trans)
|
|
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;
|
|
}
|
|
else if (png_ptr->transformations & PNG_EXPAND)
|
|
{
|
|
if (png_ptr->num_trans)
|
|
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)
|
|
if (png_ptr->transformations & PNG_BACKGROUND)
|
|
{
|
|
info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
|
|
info_ptr->num_trans = 0;
|
|
info_ptr->background = png_ptr->background;
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_16_TO_8_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_16_TO_8) && info_ptr->bit_depth == 16)
|
|
info_ptr->bit_depth = 8;
|
|
#endif
|
|
|
|
#if defined(PNG_READ_DITHER_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_DITHER)
|
|
{
|
|
if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
|
|
(info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
|
|
png_ptr->palette_lookup && info_ptr->bit_depth == 8)
|
|
{
|
|
info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_PACK_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_PACK) && info_ptr->bit_depth < 8)
|
|
info_ptr->bit_depth = 8;
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
|
|
!(info_ptr->color_type & PNG_COLOR_MASK_COLOR))
|
|
info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
|
|
#endif
|
|
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
info_ptr->channels = 1;
|
|
else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
|
|
info_ptr->channels = 3;
|
|
else
|
|
info_ptr->channels = 1;
|
|
if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
|
|
info_ptr->channels++;
|
|
info_ptr->pixel_depth = info_ptr->channels * info_ptr->bit_depth;
|
|
info_ptr->rowbytes = ((info_ptr->width * info_ptr->pixel_depth + 7) >> 3);
|
|
}
|
|
|
|
/* 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
|
|
png_do_read_transformations(png_struct *png_ptr)
|
|
{
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_EXPAND) &&
|
|
png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
|
|
}
|
|
else if (png_ptr->transformations & PNG_EXPAND)
|
|
{
|
|
if (png_ptr->num_trans)
|
|
png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
&(png_ptr->trans_values));
|
|
else
|
|
png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
NULL);
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_BACKGROUND)
|
|
png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
&(png_ptr->trans_values), &(png_ptr->background),
|
|
&(png_ptr->background_1),
|
|
png_ptr->gamma_table, png_ptr->gamma_from_1,
|
|
png_ptr->gamma_to_1, png_ptr->gamma_16_table,
|
|
png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,
|
|
png_ptr->gamma_shift);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_GAMMA) &&
|
|
!(png_ptr->transformations & PNG_BACKGROUND))
|
|
png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
png_ptr->gamma_table, png_ptr->gamma_16_table,
|
|
png_ptr->gamma_shift);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_16_TO_8_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_16_TO_8)
|
|
png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_DITHER_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_DITHER)
|
|
{
|
|
png_do_dither((png_row_info *)&(png_ptr->row_info),
|
|
png_ptr->row_buf + 1,
|
|
png_ptr->palette_lookup,
|
|
png_ptr->dither_index);
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_INVERT_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_INVERT_MONO)
|
|
png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_SHIFT_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_SHIFT)
|
|
png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
&(png_ptr->shift));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_PACK_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_PACK)
|
|
png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_BGR_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_BGR)
|
|
png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_GRAY_TO_RGB)
|
|
png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_SWAP_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_SWAP_BYTES)
|
|
png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_FILLER_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_FILLER)
|
|
png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
png_ptr->filler, png_ptr->filler_loc);
|
|
#endif
|
|
}
|
|
|
|
#if defined(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. */
|
|
void
|
|
png_do_unpack(png_row_info *row_info, png_bytef *row)
|
|
{
|
|
int shift;
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
|
|
if (row && row_info && row_info->bit_depth < 8)
|
|
{
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 3);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = 7 - (int)((row_info->width + 7) & 7);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
*dp = (*sp >> shift) & 0x1;
|
|
if (shift == 7)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift++;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 2);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
*dp = (*sp >> shift) & 0x3;
|
|
if (shift == 6)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 2;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 1);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = (int)((1 - ((row_info->width + 1) & 1)) << 4);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
*dp = (*sp >> shift) & 0xf;
|
|
if (shift == 4)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift = 4;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 8 * row_info->channels;
|
|
row_info->rowbytes = row_info->width * row_info->channels;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(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 */
|
|
void
|
|
png_do_unshift(png_row_info *row_info, png_bytef *row,
|
|
png_color_8 *sig_bits)
|
|
{
|
|
png_bytef *bp;
|
|
png_uint_16 value;
|
|
png_uint_32 i;
|
|
if (row && row_info && sig_bits &&
|
|
row_info->color_type != PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
int shift[4];
|
|
int channels;
|
|
|
|
channels = 0;
|
|
if (row_info->color_type & PNG_COLOR_MASK_COLOR)
|
|
{
|
|
shift[channels++] = row_info->bit_depth - sig_bits->red;
|
|
shift[channels++] = row_info->bit_depth - sig_bits->green;
|
|
shift[channels++] = row_info->bit_depth - sig_bits->blue;
|
|
}
|
|
else
|
|
{
|
|
shift[channels++] = row_info->bit_depth - sig_bits->gray;
|
|
}
|
|
if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
|
|
{
|
|
shift[channels++] = row_info->bit_depth - sig_bits->alpha;
|
|
}
|
|
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 2:
|
|
{
|
|
for (bp = row, i = 0;
|
|
i < row_info->rowbytes;
|
|
i++, bp++)
|
|
{
|
|
*bp >>= 1;
|
|
*bp &= 0x55;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
png_byte mask;
|
|
mask = (png_byte)(((int)0xf0 >> shift[0]) & (int)0xf0) |
|
|
((int)0xf >> shift[0]);
|
|
for (bp = row, i = 0;
|
|
i < row_info->rowbytes;
|
|
i++, bp++)
|
|
{
|
|
*bp >>= shift[0];
|
|
*bp &= mask;
|
|
}
|
|
break;
|
|
}
|
|
case 8:
|
|
{
|
|
for (bp = row, i = 0;
|
|
i < row_info->width; i++)
|
|
{
|
|
int c;
|
|
|
|
for (c = 0; c < row_info->channels; c++, bp++)
|
|
{
|
|
*bp >>= shift[c];
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 16:
|
|
{
|
|
for (bp = row, i = 0;
|
|
i < row_info->width; i++)
|
|
{
|
|
int c;
|
|
|
|
for (c = 0; c < row_info->channels; c++, bp += 2)
|
|
{
|
|
value = (*bp << 8) + *(bp + 1);
|
|
value >>= shift[c];
|
|
*bp = value >> 8;
|
|
*(bp + 1) = value & 0xff;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_16_TO_8_SUPPORTED)
|
|
/* chop rows of bit depth 16 down to 8 */
|
|
void
|
|
png_do_chop(png_row_info *row_info, png_bytef *row)
|
|
{
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
if (row && row_info && row_info->bit_depth == 16)
|
|
{
|
|
sp = row + 2;
|
|
dp = row + 1;
|
|
for (i = 1; i < row_info->width * row_info->channels; i++)
|
|
{
|
|
*dp = *sp;
|
|
sp += 2;
|
|
dp++;
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 8 * row_info->channels;
|
|
row_info->rowbytes = row_info->width * row_info->channels;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_FILLER_SUPPORTED)
|
|
/* add filler byte */
|
|
void
|
|
png_do_read_filler(png_row_info *row_info, png_bytef *row,
|
|
png_byte filler, png_byte filler_loc)
|
|
{
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
if (row && row_info && row_info->color_type == 2 &&
|
|
row_info->bit_depth == 8)
|
|
{
|
|
if (filler_loc == PNG_FILLER_AFTER)
|
|
{
|
|
for (i = 1, sp = row + (png_size_t)row_info->width * 3,
|
|
dp = row + (png_size_t)row_info->width * 4;
|
|
i < row_info->width;
|
|
i++)
|
|
{
|
|
*(--dp) = filler;
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
}
|
|
*(--dp) = filler;
|
|
row_info->channels = 4;
|
|
row_info->pixel_depth = 32;
|
|
row_info->rowbytes = row_info->width * 4;
|
|
}
|
|
else
|
|
{
|
|
for (i = 0, sp = row + (png_size_t)row_info->width * 3,
|
|
dp = row + (png_size_t)row_info->width * 4;
|
|
i < row_info->width;
|
|
i++)
|
|
{
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = filler;
|
|
}
|
|
row_info->channels = 4;
|
|
row_info->pixel_depth = 32;
|
|
row_info->rowbytes = row_info->width * 4;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
/* expand grayscale files to rgb, with or without alpha */
|
|
void
|
|
png_do_gray_to_rgb(png_row_info *row_info, png_bytef *row)
|
|
{
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
if (row && row_info && row_info->bit_depth >= 8 &&
|
|
!(row_info->color_type & PNG_COLOR_MASK_COLOR))
|
|
{
|
|
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
for (i = 0, sp = row + (png_size_t)row_info->width - 1,
|
|
dp = row + (png_size_t)row_info->width * 3 - 1;
|
|
i < row_info->width;
|
|
i++)
|
|
{
|
|
*(dp--) = *sp;
|
|
*(dp--) = *sp;
|
|
*(dp--) = *sp;
|
|
sp--;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for (i = 0, sp = row + (png_size_t)row_info->width * 2 - 1,
|
|
dp = row + (png_size_t)row_info->width * 6 - 1;
|
|
i < row_info->width;
|
|
i++)
|
|
{
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
sp--;
|
|
sp--;
|
|
}
|
|
}
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
for (i = 0, sp = row + (png_size_t)row_info->width * 2 - 1,
|
|
dp = row + (png_size_t)row_info->width * 4 - 1;
|
|
i < row_info->width;
|
|
i++)
|
|
{
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *sp;
|
|
*(dp--) = *sp;
|
|
sp--;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for (i = 0, sp = row + (png_size_t)row_info->width * 4 - 1,
|
|
dp = row + (png_size_t)row_info->width * 8 - 1;
|
|
i < row_info->width;
|
|
i++)
|
|
{
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
sp--;
|
|
sp--;
|
|
}
|
|
}
|
|
}
|
|
row_info->channels += 2;
|
|
row_info->color_type |= PNG_COLOR_MASK_COLOR;
|
|
row_info->pixel_depth = row_info->channels * row_info->bit_depth;
|
|
row_info->rowbytes = ((row_info->width *
|
|
row_info->pixel_depth + 7) >> 3);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* build a grayscale palette. Palette is assumed to be 1 << bit_depth
|
|
large of png_color. This lets grayscale images be treated as
|
|
paletted. Most useful for gamma correction and simplification
|
|
of code. */
|
|
void
|
|
png_build_grayscale_palette(int bit_depth, png_color *palette)
|
|
{
|
|
int num_palette;
|
|
int color_inc;
|
|
int i;
|
|
int v;
|
|
|
|
if (!palette)
|
|
return;
|
|
|
|
switch (bit_depth)
|
|
{
|
|
case 1:
|
|
num_palette = 2;
|
|
color_inc = 0xff;
|
|
break;
|
|
case 2:
|
|
num_palette = 4;
|
|
color_inc = 0x55;
|
|
break;
|
|
case 4:
|
|
num_palette = 16;
|
|
color_inc = 0x11;
|
|
break;
|
|
case 8:
|
|
num_palette = 256;
|
|
color_inc = 1;
|
|
break;
|
|
default:
|
|
num_palette = 0;
|
|
break;
|
|
}
|
|
|
|
for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
|
|
{
|
|
palette[i].red = v;
|
|
palette[i].green = v;
|
|
palette[i].blue = v;
|
|
}
|
|
}
|
|
|
|
#if defined(PNG_READ_DITHER_SUPPORTED)
|
|
void
|
|
png_correct_palette(png_struct *png_ptr, png_color *palette,
|
|
int num_palette)
|
|
{
|
|
if ((png_ptr->transformations & (PNG_GAMMA)) &&
|
|
(png_ptr->transformations & (PNG_BACKGROUND)))
|
|
{
|
|
if (png_ptr->color_type == 3)
|
|
{
|
|
int i;
|
|
png_color back, back_1;
|
|
|
|
back.red = png_ptr->gamma_table[png_ptr->palette[
|
|
png_ptr->background.index].red];
|
|
back.green = png_ptr->gamma_table[png_ptr->palette[
|
|
png_ptr->background.index].green];
|
|
back.blue = png_ptr->gamma_table[png_ptr->palette[
|
|
png_ptr->background.index].blue];
|
|
|
|
back_1.red = png_ptr->gamma_to_1[png_ptr->palette[
|
|
png_ptr->background.index].red];
|
|
back_1.green = png_ptr->gamma_to_1[png_ptr->palette[
|
|
png_ptr->background.index].green];
|
|
back_1.blue = png_ptr->gamma_to_1[png_ptr->palette[
|
|
png_ptr->background.index].blue];
|
|
|
|
for (i = 0; i < num_palette; i++)
|
|
{
|
|
if (i < (int)png_ptr->num_trans &&
|
|
png_ptr->trans[i] == 0)
|
|
{
|
|
palette[i] = back;
|
|
}
|
|
else if (i < (int)png_ptr->num_trans &&
|
|
png_ptr->trans[i] != 0xff)
|
|
{
|
|
int v;
|
|
|
|
v = png_ptr->gamma_to_1[png_ptr->palette[i].red];
|
|
v = (int)(((png_uint_32)(v) *
|
|
(png_uint_32)(png_ptr->trans[i]) +
|
|
(png_uint_32)(back_1.red) *
|
|
(png_uint_32)(255 - png_ptr->trans[i]) +
|
|
127) / 255);
|
|
palette[i].red = png_ptr->gamma_from_1[v];
|
|
|
|
v = png_ptr->gamma_to_1[png_ptr->palette[i].green];
|
|
v = (int)(((png_uint_32)(v) *
|
|
(png_uint_32)(png_ptr->trans[i]) +
|
|
(png_uint_32)(back_1.green) *
|
|
(png_uint_32)(255 - png_ptr->trans[i]) +
|
|
127) / 255);
|
|
palette[i].green = png_ptr->gamma_from_1[v];
|
|
|
|
v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];
|
|
v = (int)(((png_uint_32)(v) *
|
|
(png_uint_32)(png_ptr->trans[i]) +
|
|
(png_uint_32)(back_1.blue) *
|
|
(png_uint_32)(255 - png_ptr->trans[i]) +
|
|
127) / 255);
|
|
palette[i].blue = png_ptr->gamma_from_1[v];
|
|
}
|
|
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];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
int i, back;
|
|
|
|
back = png_ptr->gamma_table[png_ptr->background.gray];
|
|
|
|
for (i = 0; i < num_palette; i++)
|
|
{
|
|
if (palette[i].red == png_ptr->trans_values.gray)
|
|
{
|
|
palette[i].red = back;
|
|
palette[i].green = back;
|
|
palette[i].blue = back;
|
|
}
|
|
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];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else if (png_ptr->transformations & (PNG_GAMMA))
|
|
{
|
|
int i;
|
|
|
|
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];
|
|
}
|
|
}
|
|
else if (png_ptr->transformations & (PNG_BACKGROUND))
|
|
{
|
|
if (png_ptr->color_type == 3)
|
|
{
|
|
int i;
|
|
png_byte br, bg, bb;
|
|
|
|
br = palette[png_ptr->background.index].red;
|
|
bg = palette[png_ptr->background.index].green;
|
|
bb = palette[png_ptr->background.index].blue;
|
|
|
|
for (i = 0; i < num_palette; i++)
|
|
{
|
|
if (i >= (int)png_ptr->num_trans ||
|
|
png_ptr->trans[i] == 0)
|
|
{
|
|
palette[i].red = br;
|
|
palette[i].green = bg;
|
|
palette[i].blue = bb;
|
|
}
|
|
else if (i < (int)png_ptr->num_trans ||
|
|
png_ptr->trans[i] != 0xff)
|
|
{
|
|
palette[i].red = (png_byte)((
|
|
(png_uint_32)(png_ptr->palette[i].red) *
|
|
(png_uint_32)(png_ptr->trans[i]) +
|
|
(png_uint_32)(br) *
|
|
(png_uint_32)(255 - png_ptr->trans[i]) +
|
|
127) / 255);
|
|
palette[i].green = (png_byte)((
|
|
(png_uint_32)(png_ptr->palette[i].green) *
|
|
(png_uint_32)(png_ptr->trans[i]) +
|
|
(png_uint_32)(bg) *
|
|
(png_uint_32)(255 - png_ptr->trans[i]) +
|
|
127) / 255);
|
|
palette[i].blue = (png_byte)((
|
|
(png_uint_32)(png_ptr->palette[i].blue) *
|
|
(png_uint_32)(png_ptr->trans[i]) +
|
|
(png_uint_32)(bb) *
|
|
(png_uint_32)(255 - png_ptr->trans[i]) +
|
|
127) / 255);
|
|
}
|
|
}
|
|
}
|
|
else /* assume grayscale palette (what else could it be?) */
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < num_palette; i++)
|
|
{
|
|
if (i == (int)png_ptr->trans_values.gray)
|
|
{
|
|
palette[i].red = (png_byte)png_ptr->background.gray;
|
|
palette[i].green = (png_byte)png_ptr->background.gray;
|
|
palette[i].blue = (png_byte)png_ptr->background.gray;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
/* replace any alpha or transparency with the supplied background color.
|
|
background is the color (in rgb or grey or palette index, as
|
|
appropriate). note that paletted files are taken care of elsewhere */
|
|
void
|
|
png_do_background(png_row_info *row_info, png_bytef *row,
|
|
png_color_16 *trans_values, png_color_16 *background,
|
|
png_color_16 *background_1,
|
|
png_byte *gamma_table, png_byte *gamma_from_1, png_byte *gamma_to_1,
|
|
png_uint_16 **gamma_16, png_uint_16 **gamma_16_from_1,
|
|
png_uint_16 **gamma_16_to_1, int gamma_shift)
|
|
{
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
int shift;
|
|
if (row && row_info && background &&
|
|
(!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||
|
|
(row_info->color_type != PNG_COLOR_TYPE_PALETTE &&
|
|
trans_values)))
|
|
{
|
|
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_info->width; i++)
|
|
{
|
|
if (((*sp >> shift) & 0x1) ==
|
|
trans_values->gray)
|
|
{
|
|
*sp &= ((0x7f7f >> (7 - shift)) & 0xff);
|
|
*sp |= (background->gray << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 7;
|
|
sp++;
|
|
}
|
|
else
|
|
shift--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
sp = row;
|
|
shift = 6;
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if (((*sp >> shift) & 0x3) ==
|
|
trans_values->gray)
|
|
{
|
|
*sp &= ((0x3f3f >> (6 - shift)) & 0xff);
|
|
*sp |= (background->gray << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 6;
|
|
sp++;
|
|
}
|
|
else
|
|
shift -= 2;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
sp = row + 1;
|
|
shift = 4;
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if (((*sp >> shift) & 0xf) ==
|
|
trans_values->gray)
|
|
{
|
|
*sp &= ((0xf0f >> (4 - shift)) & 0xff);
|
|
*sp |= (background->gray << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 4;
|
|
sp++;
|
|
}
|
|
else
|
|
shift -= 4;
|
|
}
|
|
break;
|
|
}
|
|
case 8:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_table)
|
|
{
|
|
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp++)
|
|
{
|
|
if (*sp == trans_values->gray)
|
|
{
|
|
*sp = background->gray;
|
|
}
|
|
else
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp++)
|
|
{
|
|
if (*sp == trans_values->gray)
|
|
{
|
|
*sp = background->gray;
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 16:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp += 2)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = ((png_uint_16)(*sp) << 8) +
|
|
(png_uint_16)(*(sp + 1));
|
|
if (v == trans_values->gray)
|
|
{
|
|
*sp = (background->gray >> 8) & 0xff;
|
|
*(sp + 1) = background->gray & 0xff;
|
|
}
|
|
else
|
|
{
|
|
v = gamma_16[
|
|
*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp += 2)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = ((png_uint_16)(*sp) << 8) +
|
|
(png_uint_16)(*(sp + 1));
|
|
if (v == trans_values->gray)
|
|
{
|
|
*sp = (background->gray >> 8) & 0xff;
|
|
*(sp + 1) = background->gray & 0xff;
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_RGB:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_table)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp += 3)
|
|
{
|
|
if (*sp == trans_values->red &&
|
|
*(sp + 1) == trans_values->green &&
|
|
*(sp + 2) == trans_values->blue)
|
|
{
|
|
*sp = background->red;
|
|
*(sp + 1) = background->green;
|
|
*(sp + 2) = background->blue;
|
|
}
|
|
else
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
*(sp + 1) = gamma_table[*(sp + 1)];
|
|
*(sp + 2) = gamma_table[*(sp + 2)];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp += 3)
|
|
{
|
|
if (*sp == trans_values->red &&
|
|
*(sp + 1) == trans_values->green &&
|
|
*(sp + 2) == trans_values->blue)
|
|
{
|
|
*sp = background->red;
|
|
*(sp + 1) = background->green;
|
|
*(sp + 2) = background->blue;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp += 6)
|
|
{
|
|
png_uint_16 r, g, b;
|
|
|
|
r = ((png_uint_16)(*sp) << 8) +
|
|
(png_uint_16)(*(sp + 1));
|
|
g = ((png_uint_16)(*(sp + 2)) << 8) +
|
|
(png_uint_16)(*(sp + 3));
|
|
b = ((png_uint_16)(*(sp + 4)) << 8) +
|
|
(png_uint_16)(*(sp + 5));
|
|
if (r == trans_values->red &&
|
|
g == trans_values->green &&
|
|
b == trans_values->blue)
|
|
{
|
|
*sp = (background->red >> 8) & 0xff;
|
|
*(sp + 1) = background->red & 0xff;
|
|
*(sp + 2) = (background->green >> 8) & 0xff;
|
|
*(sp + 3) = background->green & 0xff;
|
|
*(sp + 4) = (background->blue >> 8) & 0xff;
|
|
*(sp + 5) = background->blue & 0xff;
|
|
}
|
|
else
|
|
{
|
|
png_uint_16 v;
|
|
v = gamma_16[
|
|
*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
v = gamma_16[
|
|
*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
*(sp + 2) = (v >> 8) & 0xff;
|
|
*(sp + 3) = v & 0xff;
|
|
v = gamma_16[
|
|
*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
*(sp + 4) = (v >> 8) & 0xff;
|
|
*(sp + 5) = v & 0xff;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++, sp += 6)
|
|
{
|
|
png_uint_16 r, g, b;
|
|
|
|
r = ((png_uint_16)(*sp) << 8) +
|
|
(png_uint_16)(*(sp + 1));
|
|
g = ((png_uint_16)(*(sp + 2)) << 8) +
|
|
(png_uint_16)(*(sp + 3));
|
|
b = ((png_uint_16)(*(sp + 4)) << 8) +
|
|
(png_uint_16)(*(sp + 5));
|
|
if (r == trans_values->red &&
|
|
g == trans_values->green &&
|
|
b == trans_values->blue)
|
|
{
|
|
*sp = (background->red >> 8) & 0xff;
|
|
*(sp + 1) = background->red & 0xff;
|
|
*(sp + 2) = (background->green >> 8) & 0xff;
|
|
*(sp + 3) = background->green & 0xff;
|
|
*(sp + 4) = (background->blue >> 8) & 0xff;
|
|
*(sp + 5) = background->blue & 0xff;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
{
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 8:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_to_1 && gamma_from_1 && gamma_table)
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 2, dp++)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = *(sp + 1);
|
|
if (a == 0xff)
|
|
{
|
|
*dp = gamma_table[*sp];
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = background->gray;
|
|
}
|
|
else
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_to_1[*sp];
|
|
v = ((png_uint_16)(v) * a +
|
|
(png_uint_16)background_1->gray *
|
|
(255 - a) + 127) / 255;
|
|
*dp = gamma_from_1[v];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 2, dp++)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = *(sp + 1);
|
|
if (a == 0xff)
|
|
{
|
|
*dp = *sp;
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = background->gray;
|
|
}
|
|
else
|
|
{
|
|
*dp = ((png_uint_16)(*sp) * a +
|
|
(png_uint_16)background_1->gray *
|
|
(255 - a) + 127) / 255;
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 16:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16 && gamma_16_from_1 && gamma_16_to_1)
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 4, dp += 2)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = ((png_uint_16)(*(sp + 2)) << 8) +
|
|
(png_uint_16)(*(sp + 3));
|
|
if (a == (png_uint_16)0xffff)
|
|
{
|
|
png_uint_32 v;
|
|
|
|
v = gamma_16[
|
|
*(sp + 1) >> gamma_shift][*sp];
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = (background->gray >> 8) & 0xff;
|
|
*(dp + 1) = background->gray & 0xff;
|
|
}
|
|
else
|
|
{
|
|
png_uint_32 g, v;
|
|
|
|
g = gamma_16_to_1[
|
|
*(sp + 1) >> gamma_shift][*sp];
|
|
v = (g * (png_uint_32)a +
|
|
(png_uint_32)background_1->gray *
|
|
(png_uint_32)((png_uint_16)65535L - a) +
|
|
(png_uint_16)32767) / (png_uint_16)65535L;
|
|
v = gamma_16_from_1[(size_t)(
|
|
(v & 0xff) >> gamma_shift)][(size_t)(v >> 8)];
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 4, dp += 2)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = ((png_uint_16)(*(sp + 2)) << 8) +
|
|
(png_uint_16)(*(sp + 3));
|
|
if (a == (png_uint_16)0xffff)
|
|
{
|
|
png_memcpy(dp, sp, 2);
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = (background->gray >> 8) & 0xff;
|
|
*(dp + 1) = background->gray & 0xff;
|
|
}
|
|
else
|
|
{
|
|
png_uint_32 g, v;
|
|
|
|
g = ((png_uint_32)(*sp) << 8) +
|
|
(png_uint_32)(*(sp + 1));
|
|
v = (g * (png_uint_32)a +
|
|
(png_uint_32)background_1->gray *
|
|
(png_uint_32)((png_uint_16)65535L - a) +
|
|
(png_uint_16)32767) / (png_uint_16)65535L;
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_to_1 && gamma_from_1 && gamma_table)
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 4, dp += 3)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = *(sp + 3);
|
|
if (a == 0xff)
|
|
{
|
|
*dp = gamma_table[*sp];
|
|
*(dp + 1) = gamma_table[*(sp + 1)];
|
|
*(dp + 2) = gamma_table[*(sp + 2)];
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = background->red;
|
|
*(dp + 1) = background->green;
|
|
*(dp + 2) = background->blue;
|
|
}
|
|
else
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_to_1[*sp];
|
|
v = ((png_uint_16)(v) * a +
|
|
(png_uint_16)background_1->red *
|
|
(255 - a) + 127) / 255;
|
|
*dp = gamma_from_1[v];
|
|
v = gamma_to_1[*(sp + 1)];
|
|
v = ((png_uint_16)(v) * a +
|
|
(png_uint_16)background_1->green *
|
|
(255 - a) + 127) / 255;
|
|
*(dp + 1) = gamma_from_1[v];
|
|
v = gamma_to_1[*(sp + 2)];
|
|
v = ((png_uint_16)(v) * a +
|
|
(png_uint_16)background_1->blue *
|
|
(255 - a) + 127) / 255;
|
|
*(dp + 2) = gamma_from_1[v];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 4, dp += 3)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = *(sp + 3);
|
|
if (a == 0xff)
|
|
{
|
|
*dp = *sp;
|
|
*(dp + 1) = *(sp + 1);
|
|
*(dp + 2) = *(sp + 2);
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = background->red;
|
|
*(dp + 1) = background->green;
|
|
*(dp + 2) = background->blue;
|
|
}
|
|
else
|
|
{
|
|
*dp = ((png_uint_16)(*sp) * a +
|
|
(png_uint_16)background->red *
|
|
(255 - a) + 127) / 255;
|
|
*(dp + 1) = ((png_uint_16)(*(sp + 1)) * a +
|
|
(png_uint_16)background->green *
|
|
(255 - a) + 127) / 255;
|
|
*(dp + 2) = ((png_uint_16)(*(sp + 2)) * a +
|
|
(png_uint_16)background->blue *
|
|
(255 - a) + 127) / 255;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16 && gamma_16_from_1 && gamma_16_to_1)
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 8, dp += 6)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = ((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];
|
|
*dp = (v >> 8) & 0xff;
|
|
*(dp + 1) = v & 0xff;
|
|
v = gamma_16[
|
|
*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
*(dp + 2) = (v >> 8) & 0xff;
|
|
*(dp + 3) = v & 0xff;
|
|
v = gamma_16[
|
|
*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
*(dp + 4) = (v >> 8) & 0xff;
|
|
*(dp + 5) = v & 0xff;
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = (background->red >> 8) & 0xff;
|
|
*(dp + 1) = background->red & 0xff;
|
|
*(dp + 2) = (background->green >> 8) & 0xff;
|
|
*(dp + 3) = background->green & 0xff;
|
|
*(dp + 4) = (background->blue >> 8) & 0xff;
|
|
*(dp + 5) = background->blue & 0xff;
|
|
}
|
|
else
|
|
{
|
|
png_uint_32 v;
|
|
|
|
v = gamma_16_to_1[
|
|
*(sp + 1) >> gamma_shift][*sp];
|
|
v = (v * (png_uint_32)a +
|
|
(png_uint_32)background->red *
|
|
(png_uint_32)((png_uint_16)65535L - a) +
|
|
(png_uint_16)32767) / (png_uint_16)65535L;
|
|
v = gamma_16_from_1[(size_t)(
|
|
(v & 0xff) >> gamma_shift)][(size_t)(v >> 8)];
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
v = gamma_16_to_1[
|
|
*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
v = (v * (png_uint_32)a +
|
|
(png_uint_32)background->green *
|
|
(png_uint_32)((png_uint_16)65535L - a) +
|
|
(png_uint_16)32767) / (png_uint_16)65535L;
|
|
v = gamma_16_from_1[(size_t)(
|
|
(v & 0xff) >> gamma_shift)][(size_t)(v >> 8)];
|
|
*(dp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 3) = (png_byte)(v & 0xff);
|
|
v = gamma_16_to_1[
|
|
*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
v = (v * (png_uint_32)a +
|
|
(png_uint_32)background->blue *
|
|
(png_uint_32)((png_uint_16)65535L - a) +
|
|
(png_uint_16)32767) / (png_uint_16)65535L;
|
|
v = gamma_16_from_1[(size_t)(
|
|
(v & 0xff) >> gamma_shift)][(size_t)(v >> 8)];
|
|
*(dp + 4) = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 5) = (png_byte)(v & 0xff);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
for (i = 0, sp = row,
|
|
dp = row;
|
|
i < row_info->width; i++, sp += 8, dp += 6)
|
|
{
|
|
png_uint_16 a;
|
|
|
|
a = ((png_uint_16)(*(sp + 6)) << 8) +
|
|
(png_uint_16)(*(sp + 7));
|
|
if (a == (png_uint_16)0xffff)
|
|
{
|
|
png_memcpy(dp, sp, 6);
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = (background->red >> 8) & 0xff;
|
|
*(dp + 1) = background->red & 0xff;
|
|
*(dp + 2) = (background->green >> 8) & 0xff;
|
|
*(dp + 3) = background->green & 0xff;
|
|
*(dp + 4) = (background->blue >> 8) & 0xff;
|
|
*(dp + 5) = background->blue & 0xff;
|
|
}
|
|
else
|
|
{
|
|
png_uint_32 r, g, b, v;
|
|
|
|
r = ((png_uint_32)(*sp) << 8) +
|
|
(png_uint_32)(*(sp + 1));
|
|
g = ((png_uint_32)(*(sp + 2)) << 8) +
|
|
(png_uint_32)(*(sp + 3));
|
|
b = ((png_uint_32)(*(sp + 4)) << 8) +
|
|
(png_uint_32)(*(sp + 5));
|
|
v = (r * (png_uint_32)a +
|
|
(png_uint_32)background->red *
|
|
(png_uint_32)((png_uint_32)65535L - a) +
|
|
(png_uint_32)32767) / (png_uint_32)65535L;
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
v = (g * (png_uint_32)a +
|
|
(png_uint_32)background->green *
|
|
(png_uint_32)((png_uint_32)65535L - a) +
|
|
(png_uint_32)32767) / (png_uint_32)65535L;
|
|
*(dp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 3) = (png_byte)(v & 0xff);
|
|
v = (b * (png_uint_32)a +
|
|
(png_uint_32)background->blue *
|
|
(png_uint_32)((png_uint_32)65535L - a) +
|
|
(png_uint_32)32767) / (png_uint_32)65535L;
|
|
*(dp + 4) = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 5) = (png_byte)(v & 0xff);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
|
|
{
|
|
row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
|
|
row_info->channels -= 1;
|
|
row_info->pixel_depth = row_info->channels *
|
|
row_info->bit_depth;
|
|
row_info->rowbytes = ((row_info->width *
|
|
row_info->pixel_depth + 7) >> 3);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
/* gamma correct the image, avoiding the alpha channel. Make sure
|
|
you do this after you deal with the trasparency 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(). If your bit depth < 8, gamma correct a
|
|
palette, not the data. */
|
|
void
|
|
png_do_gamma(png_row_info *row_info, png_bytef *row,
|
|
png_byte *gamma_table, png_uint_16 **gamma_16_table,
|
|
int gamma_shift)
|
|
{
|
|
png_bytef *sp;
|
|
png_uint_32 i;
|
|
if (row && row_info && ((row_info->bit_depth <= 8 && gamma_table) ||
|
|
(row_info->bit_depth == 16 && gamma_16_table)))
|
|
{
|
|
switch (row_info->color_type)
|
|
{
|
|
case PNG_COLOR_TYPE_RGB:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++)
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 2;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->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)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 4;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++)
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
sp++;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 4;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_GRAY:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++)
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
for (i = 0, sp = row;
|
|
i < row_info->width; i++)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_16_table[*(sp + 1) >>
|
|
gamma_shift][*sp];
|
|
*sp = (v >> 8) & 0xff;
|
|
*(sp + 1) = v & 0xff;
|
|
sp += 2;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
/* expands a palette row to an rgb or rgba row depending
|
|
upon whether you supply trans and num_trans */
|
|
void
|
|
png_do_expand_palette(png_row_info *row_info, png_bytef *row,
|
|
png_color *palette,
|
|
png_byte *trans, int num_trans)
|
|
{
|
|
int shift, value;
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
if (row && row_info && 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_info->width - 1) >> 3);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = 7 - (int)((row_info->width + 7) & 7);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if ((*sp >> shift) & 0x1)
|
|
*dp = 1;
|
|
else
|
|
*dp = 0;
|
|
if (shift == 7)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift++;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 2);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0x3;
|
|
*dp = value;
|
|
if (shift == 6)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 2;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 1);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = (int)((row_info->width & 1) << 2);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0xf;
|
|
*dp = value;
|
|
if (shift == 4)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 4;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 8;
|
|
row_info->rowbytes = row_info->width;
|
|
}
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 8:
|
|
{
|
|
if (trans)
|
|
{
|
|
sp = row + (png_size_t)row_info->width - 1;
|
|
dp = row + (png_size_t)(row_info->width << 2) - 1;
|
|
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if (*sp >= (png_byte)num_trans)
|
|
*dp-- = 0xff;
|
|
else
|
|
*dp-- = trans[*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_info->width * 4;
|
|
row_info->color_type = 6;
|
|
row_info->channels = 4;
|
|
}
|
|
else
|
|
{
|
|
sp = row + (png_size_t)row_info->width - 1;
|
|
dp = row + (png_size_t)(row_info->width * 3) - 1;
|
|
|
|
for (i = 0; i < row_info->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_info->width * 3;
|
|
row_info->color_type = 2;
|
|
row_info->channels = 3;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* if the bit depth < 8, it is expanded to 8. Also, if the
|
|
transparency value is supplied, an alpha channel is built. */
|
|
void
|
|
png_do_expand(png_row_info *row_info, png_bytef *row,
|
|
png_color_16 *trans_value)
|
|
{
|
|
int shift, value;
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
if (row && row_info)
|
|
{
|
|
if (row_info->color_type == PNG_COLOR_TYPE_GRAY &&
|
|
row_info->bit_depth < 8)
|
|
{
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 3);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = 7 - (int)((row_info->width + 7) & 7);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if ((*sp >> shift) & 0x1)
|
|
*dp = 0xff;
|
|
else
|
|
*dp = 0;
|
|
if (shift == 7)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift++;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 2);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0x3;
|
|
*dp = (value | (value << 2) | (value << 4) |
|
|
(value << 6));
|
|
if (shift == 6)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 2;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
sp = row + (png_size_t)((row_info->width - 1) >> 1);
|
|
dp = row + (png_size_t)row_info->width - 1;
|
|
shift = (int)((1 - ((row_info->width + 1) & 1)) << 2);
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0xf;
|
|
*dp = (value | (value << 4));
|
|
if (shift == 4)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift = 4;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 8;
|
|
row_info->rowbytes = row_info->width;
|
|
}
|
|
if (row_info->color_type == PNG_COLOR_TYPE_GRAY && trans_value)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
sp = row + (png_size_t)row_info->width - 1;
|
|
dp = row + (png_size_t)(row_info->width << 1) - 1;
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if (*sp == trans_value->gray)
|
|
*dp-- = 0;
|
|
else
|
|
*dp-- = 0xff;
|
|
*dp-- = *sp--;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
sp = row + (png_size_t)row_info->rowbytes - 1;
|
|
dp = row + (png_size_t)(row_info->rowbytes << 1) - 1;
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if (((png_uint_16)*(sp) |
|
|
((png_uint_16)*(sp - 1) << 8)) == trans_value->gray)
|
|
{
|
|
*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 = (row_info->bit_depth << 1);
|
|
row_info->rowbytes =
|
|
((row_info->width * row_info->pixel_depth) >> 3);
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
sp = row + (png_size_t)row_info->rowbytes - 1;
|
|
dp = row + (png_size_t)(row_info->width << 2) - 1;
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if (*(sp - 2) == trans_value->red &&
|
|
*(sp - 1) == trans_value->green &&
|
|
*(sp - 0) == trans_value->blue)
|
|
*dp-- = 0;
|
|
else
|
|
*dp-- = 0xff;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
sp = row + (png_size_t)row_info->rowbytes - 1;
|
|
dp = row + (png_size_t)(row_info->width << 3) - 1;
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
if ((((png_uint_16)*(sp - 4) |
|
|
((png_uint_16)*(sp - 5) << 8)) == trans_value->red) &&
|
|
(((png_uint_16)*(sp - 2) |
|
|
((png_uint_16)*(sp - 3) << 8)) == trans_value->green) &&
|
|
(((png_uint_16)*(sp - 0) |
|
|
((png_uint_16)*(sp - 1) << 8)) == trans_value->blue))
|
|
{
|
|
*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 = (row_info->bit_depth << 2);
|
|
row_info->rowbytes =
|
|
((row_info->width * row_info->pixel_depth) >> 3);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_DITHER_SUPPORTED)
|
|
void
|
|
png_do_dither(png_row_info *row_info, png_bytef *row,
|
|
png_byte *palette_lookup, png_byte *dither_lookup)
|
|
{
|
|
png_bytef *sp, *dp;
|
|
png_uint_32 i;
|
|
if (row && row_info)
|
|
{
|
|
if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
|
|
palette_lookup && row_info->bit_depth == 8)
|
|
{
|
|
int r, g, b, p;
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_info->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_DITHER_RED_BITS)) &
|
|
((1 << PNG_DITHER_RED_BITS) - 1)) <<
|
|
(PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
|
|
(((g >> (8 - PNG_DITHER_GREEN_BITS)) &
|
|
((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
|
|
(PNG_DITHER_BLUE_BITS)) |
|
|
((b >> (8 - PNG_DITHER_BLUE_BITS)) &
|
|
((1 << PNG_DITHER_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 =
|
|
((row_info->width * row_info->pixel_depth + 7) >> 3);
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
|
|
palette_lookup && row_info->bit_depth == 8)
|
|
{
|
|
int r, g, b, p;
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_info->width; i++)
|
|
{
|
|
r = *sp++;
|
|
g = *sp++;
|
|
b = *sp++;
|
|
sp++;
|
|
|
|
p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
|
|
((1 << PNG_DITHER_RED_BITS) - 1)) <<
|
|
(PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
|
|
(((g >> (8 - PNG_DITHER_GREEN_BITS)) &
|
|
((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
|
|
(PNG_DITHER_BLUE_BITS)) |
|
|
((b >> (8 - PNG_DITHER_BLUE_BITS)) &
|
|
((1 << PNG_DITHER_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 =
|
|
((row_info->width * row_info->pixel_depth + 7) >> 3);
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
|
|
dither_lookup && row_info->bit_depth == 8)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_info->width; i++, sp++)
|
|
{
|
|
*sp = dither_lookup[*sp];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
static int png_gamma_shift[] =
|
|
{0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0};
|
|
|
|
void
|
|
png_build_gamma_table(png_struct *png_ptr)
|
|
{
|
|
if (png_ptr->bit_depth <= 8)
|
|
{
|
|
int i;
|
|
double g;
|
|
|
|
g = 1.0 / (png_ptr->gamma * png_ptr->display_gamma);
|
|
|
|
png_ptr->gamma_table = (png_byte *)png_malloc(png_ptr,
|
|
(png_uint_32)256);
|
|
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,
|
|
g) * 255.0 + .5);
|
|
}
|
|
|
|
if (png_ptr->transformations & PNG_BACKGROUND)
|
|
{
|
|
g = 1.0 / (png_ptr->gamma);
|
|
|
|
png_ptr->gamma_to_1 = (png_byte *)png_malloc(png_ptr,
|
|
(png_uint_32)256);
|
|
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,
|
|
g) * 255.0 + .5);
|
|
}
|
|
|
|
g = 1.0 / (png_ptr->display_gamma);
|
|
|
|
png_ptr->gamma_from_1 = (png_byte *)png_malloc(png_ptr,
|
|
(png_uint_32)256);
|
|
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
|
|
g) * 255.0 + .5);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
double g;
|
|
int i, j, shift, num;
|
|
int sig_bit;
|
|
png_uint_32 ig;
|
|
|
|
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
|
|
{
|
|
sig_bit = (int)png_ptr->sig_bit.red;
|
|
if ((int)png_ptr->sig_bit.green > sig_bit)
|
|
sig_bit = png_ptr->sig_bit.green;
|
|
if ((int)png_ptr->sig_bit.blue > sig_bit)
|
|
sig_bit = png_ptr->sig_bit.blue;
|
|
}
|
|
else
|
|
{
|
|
sig_bit = (int)png_ptr->sig_bit.gray;
|
|
}
|
|
|
|
if (sig_bit > 0)
|
|
shift = 16 - sig_bit;
|
|
else
|
|
shift = 0;
|
|
|
|
if (png_ptr->transformations & PNG_16_TO_8)
|
|
{
|
|
if (shift < (16 - PNG_MAX_GAMMA_8))
|
|
shift = (16 - PNG_MAX_GAMMA_8);
|
|
}
|
|
|
|
if (shift > 8)
|
|
shift = 8;
|
|
if (shift < 0)
|
|
shift = 0;
|
|
|
|
png_ptr->gamma_shift = shift;
|
|
|
|
num = (1 << (8 - shift));
|
|
|
|
g = 1.0 / (png_ptr->gamma * png_ptr->display_gamma);
|
|
|
|
png_ptr->gamma_16_table = (png_uint_16 **)png_malloc(png_ptr,
|
|
num * sizeof (png_uint_16 *));
|
|
|
|
if ((png_ptr->transformations & PNG_16_TO_8) &&
|
|
!(png_ptr->transformations & PNG_BACKGROUND))
|
|
{
|
|
double fin, fout;
|
|
png_uint_32 last, max;
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_table[i] = (png_uint_16 *)png_malloc(png_ptr,
|
|
256 * sizeof (png_uint_16));
|
|
}
|
|
|
|
g = 1.0 / g;
|
|
last = 0;
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
fout = ((double)i + 0.5) / 256.0;
|
|
fin = pow(fout, g);
|
|
max = (png_uint_32)(fin * (double)(num << 8));
|
|
while (last <= max)
|
|
{
|
|
png_ptr->gamma_16_table[(int)(last >> 8)]
|
|
[(int)(last & 0xff)] =
|
|
(png_uint_16)i | ((png_uint_16)i << 8);
|
|
last++;
|
|
}
|
|
}
|
|
while (last < (num << 8))
|
|
{
|
|
png_ptr->gamma_16_table[(int)(last >> 8)][(int)(last & 0xff)] =
|
|
(png_uint_16)65535L;
|
|
last++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_table[i] = (png_uint_16 *)png_malloc(png_ptr,
|
|
256 * sizeof (png_uint_16));
|
|
|
|
ig = (((png_uint_32)i *
|
|
(png_uint_32)png_gamma_shift[shift]) >> 4);
|
|
for (j = 0; j < 256; j++)
|
|
{
|
|
png_ptr->gamma_16_table[i][j] =
|
|
(png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
|
|
65535.0, g) * 65535.0 + .5);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (png_ptr->transformations & PNG_BACKGROUND)
|
|
{
|
|
g = 1.0 / (png_ptr->gamma);
|
|
|
|
png_ptr->gamma_16_to_1 = (png_uint_16 **)png_malloc(png_ptr,
|
|
num * sizeof (png_uint_16 *));
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_to_1[i] = (png_uint_16 *)png_malloc(png_ptr,
|
|
256 * sizeof (png_uint_16));
|
|
|
|
ig = (((png_uint_32)i *
|
|
(png_uint_32)png_gamma_shift[shift]) >> 4);
|
|
for (j = 0; j < 256; j++)
|
|
{
|
|
png_ptr->gamma_16_to_1[i][j] =
|
|
(png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
|
|
65535.0, g) * 65535.0 + .5);
|
|
}
|
|
}
|
|
g = 1.0 / (png_ptr->display_gamma);
|
|
|
|
png_ptr->gamma_16_from_1 = (png_uint_16 **)png_malloc(png_ptr,
|
|
num * sizeof (png_uint_16 *));
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_from_1[i] = (png_uint_16 *)png_malloc(png_ptr,
|
|
256 * sizeof (png_uint_16));
|
|
|
|
ig = (((png_uint_32)i *
|
|
(png_uint_32)png_gamma_shift[shift]) >> 4);
|
|
for (j = 0; j < 256; j++)
|
|
{
|
|
png_ptr->gamma_16_from_1[i][j] =
|
|
(png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
|
|
65535.0, g) * 65535.0 + .5);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|