4302 lines
144 KiB
C
4302 lines
144 KiB
C
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/* pngrtran.c - transforms the data in a row for PNG readers
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*
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* Last changed in libpng 1.2.35 [February 12, 2009]
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* For conditions of distribution and use, see copyright notice in png.h
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* Copyright (c) 1998-2009 Glenn Randers-Pehrson
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* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
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* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
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*
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* This file contains functions optionally called by an application
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* in order to tell libpng how to handle data when reading a PNG.
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* Transformations that are used in both reading and writing are
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* in pngtrans.c.
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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_SUPPORTED)
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/* Set the action on getting a CRC error for an ancillary or critical chunk. */
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void PNGAPI
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png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
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{
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png_debug(1, "in png_set_crc_action");
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/* Tell libpng how we react to CRC errors in critical chunks */
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if (png_ptr == NULL) return;
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switch (crit_action)
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{
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case PNG_CRC_NO_CHANGE: /* leave setting as is */
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break;
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case PNG_CRC_WARN_USE: /* warn/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
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break;
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case PNG_CRC_QUIET_USE: /* quiet/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
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PNG_FLAG_CRC_CRITICAL_IGNORE;
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break;
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case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */
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png_warning(png_ptr,
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"Can't discard critical data on CRC error.");
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case PNG_CRC_ERROR_QUIT: /* error/quit */
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case PNG_CRC_DEFAULT:
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default:
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png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
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break;
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}
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switch (ancil_action)
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{
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case PNG_CRC_NO_CHANGE: /* leave setting as is */
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break;
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case PNG_CRC_WARN_USE: /* warn/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
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break;
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case PNG_CRC_QUIET_USE: /* quiet/use data */
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
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PNG_FLAG_CRC_ANCILLARY_NOWARN;
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break;
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case PNG_CRC_ERROR_QUIT: /* error/quit */
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
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break;
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case PNG_CRC_WARN_DISCARD: /* warn/discard data */
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case PNG_CRC_DEFAULT:
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default:
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png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
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break;
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}
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}
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#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
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defined(PNG_FLOATING_POINT_SUPPORTED)
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/* handle alpha and tRNS via a background color */
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void PNGAPI
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png_set_background(png_structp png_ptr,
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png_color_16p 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_debug(1, "in png_set_background");
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if (png_ptr == NULL) return;
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if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
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{
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png_warning(png_ptr, "Application must supply a known background gamma");
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return;
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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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png_sizeof(png_color_16));
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png_ptr->background_gamma = (float)background_gamma;
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png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
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png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
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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 PNGAPI
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png_set_strip_16(png_structp png_ptr)
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{
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png_debug(1, "in png_set_strip_16");
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if (png_ptr == NULL) return;
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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_STRIP_ALPHA_SUPPORTED)
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void PNGAPI
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png_set_strip_alpha(png_structp png_ptr)
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{
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png_debug(1, "in png_set_strip_alpha");
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if (png_ptr == NULL) return;
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png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
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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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* of colors is greater then the maximum number, the palette will be
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* modified to fit in the maximum number. "full_dither" indicates
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* whether we need a dithering cube set up for RGB images, or if we
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* simply are reducing the number of colors in a paletted image.
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*/
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typedef struct png_dsort_struct
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{
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struct png_dsort_struct FAR * next;
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png_byte left;
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png_byte right;
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} png_dsort;
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typedef png_dsort FAR * png_dsortp;
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typedef png_dsort FAR * FAR * png_dsortpp;
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void PNGAPI
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png_set_dither(png_structp png_ptr, png_colorp palette,
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int num_palette, int maximum_colors, png_uint_16p histogram,
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int full_dither)
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{
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png_debug(1, "in png_set_dither");
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if (png_ptr == NULL) return;
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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_bytep)png_malloc(png_ptr,
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(png_uint_32)(num_palette * png_sizeof(png_byte)));
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for (i = 0; i < num_palette; i++)
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png_ptr->dither_index[i] = (png_byte)i;
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}
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if (num_palette > maximum_colors)
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{
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if (histogram != NULL)
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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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/* initialize an array to sort colors */
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png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
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(png_uint_32)(num_palette * png_sizeof(png_byte)));
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/* initialize the dither_sort array */
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for (i = 0; i < num_palette; i++)
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png_ptr->dither_sort[i] = (png_byte)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[png_ptr->dither_sort[j]]
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< histogram[png_ptr->dither_sort[j + 1]])
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{
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png_byte t;
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t = png_ptr->dither_sort[j];
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png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
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png_ptr->dither_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 = num_palette;
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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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for (i = 0; i < maximum_colors; i++)
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{
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if ((int)png_ptr->dither_sort[i] >= maximum_colors)
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{
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do
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j--;
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while ((int)png_ptr->dither_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 = num_palette;
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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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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 ((int)png_ptr->dither_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 ((int)png_ptr->dither_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] = (png_byte)i;
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png_ptr->dither_index[i] = (png_byte)j;
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}
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}
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/* find closest color for those colors we are not using */
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for (i = 0; i < num_palette; i++)
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{
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if ((int)png_ptr->dither_index[i] >= maximum_colors)
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{
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int min_d, k, min_k, d_index;
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/* find the closest color to one we threw out */
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d_index = png_ptr->dither_index[i];
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min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
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for (k = 1, min_k = 0; k < maximum_colors; k++)
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{
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int d;
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d = PNG_COLOR_DIST(palette[d_index], palette[k]);
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if (d < min_d)
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{
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min_d = d;
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min_k = k;
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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] = (png_byte)min_k;
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}
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}
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}
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png_free(png_ptr, png_ptr->dither_sort);
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png_ptr->dither_sort = NULL;
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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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[We don't understand this at all, so if someone wants to
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work on improving it, be our guest - AED, GRP]
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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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png_dsortp t;
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png_dsortpp hash;
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t = NULL;
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/* initialize palette index arrays */
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png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
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(png_uint_32)(num_palette * png_sizeof(png_byte)));
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png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
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(png_uint_32)(num_palette * png_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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png_ptr->index_to_palette[i] = (png_byte)i;
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png_ptr->palette_to_index[i] = (png_byte)i;
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}
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hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
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png_sizeof(png_dsortp)));
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png_memset(hash, 0, 769 * png_sizeof(png_dsortp));
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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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t = (png_dsortp)png_malloc_warn(png_ptr,
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(png_uint_32)(png_sizeof(png_dsort)));
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if (t == NULL)
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break;
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t->next = hash[d];
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t->left = (png_byte)i;
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t->right = (png_byte)j;
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hash[d] = t;
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}
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}
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if (t == NULL)
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break;
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}
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if (t != NULL)
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for (i = 0; i <= max_d; i++)
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{
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if (hash[i] != NULL)
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{
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png_dsortp p;
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for (p = hash[i]; p; p = p->next)
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{
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if ((int)png_ptr->index_to_palette[p->left]
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< num_new_palette &&
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(int)png_ptr->index_to_palette[p->right]
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< num_new_palette)
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{
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int j, next_j;
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if (num_new_palette & 0x01)
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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[png_ptr->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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png_ptr->index_to_palette[j])
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png_ptr->dither_index[k] =
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png_ptr->index_to_palette[next_j];
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if ((int)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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png_ptr->index_to_palette[j];
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}
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}
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png_ptr->index_to_palette[png_ptr->palette_to_index
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[num_new_palette]] = png_ptr->index_to_palette[j];
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png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
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= png_ptr->palette_to_index[num_new_palette];
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png_ptr->index_to_palette[j] = (png_byte)num_new_palette;
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png_ptr->palette_to_index[num_new_palette] = (png_byte)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] != NULL)
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{
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png_dsortp p = hash[i];
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while (p)
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{
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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, png_ptr->palette_to_index);
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png_free(png_ptr, png_ptr->index_to_palette);
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png_ptr->palette_to_index = NULL;
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png_ptr->index_to_palette = NULL;
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}
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num_palette = maximum_colors;
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}
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if (png_ptr->palette == NULL)
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{
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png_ptr->palette = palette;
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}
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png_ptr->num_palette = (png_uint_16)num_palette;
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if (full_dither)
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{
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int i;
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png_bytep distance;
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int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
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PNG_DITHER_BLUE_BITS;
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int num_red = (1 << PNG_DITHER_RED_BITS);
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int num_green = (1 << PNG_DITHER_GREEN_BITS);
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int num_blue = (1 << PNG_DITHER_BLUE_BITS);
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png_size_t num_entries = ((png_size_t)1 << total_bits);
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png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr,
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(png_uint_32)(num_entries * png_sizeof(png_byte)));
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png_memset(png_ptr->palette_lookup, 0, num_entries *
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png_sizeof(png_byte));
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distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
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png_sizeof(png_byte)));
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png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
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for (i = 0; i < num_palette; i++)
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{
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int ir, ig, ib;
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int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
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int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
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int 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 = abs(ir - r); */
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int dr = ((ir > r) ? ir - r : r - ir);
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int 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 = abs(ig - g); */
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int dg = ((ig > g) ? ig - g : g - ig);
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int dt = dr + dg;
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int dm = ((dr > dg) ? dr : dg);
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int 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 d_index = index_g | ib;
|
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/* int db = abs(ib - b); */
|
|
int db = ((ib > b) ? ib - b : b - ib);
|
|
int dmax = ((dm > db) ? dm : db);
|
|
int d = dmax + dt + db;
|
|
|
|
if (d < (int)distance[d_index])
|
|
{
|
|
distance[d_index] = (png_byte)d;
|
|
png_ptr->palette_lookup[d_index] = (png_byte)i;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
png_free(png_ptr, distance);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
|
|
/* Transform the image from the file_gamma to the screen_gamma. We
|
|
* only do transformations on images where the file_gamma and screen_gamma
|
|
* are not close reciprocals, otherwise it slows things down slightly, and
|
|
* also needlessly introduces small errors.
|
|
*
|
|
* We will turn off gamma transformation later if no semitransparent entries
|
|
* are present in the tRNS array for palette images. We can't do it here
|
|
* because we don't necessarily have the tRNS chunk yet.
|
|
*/
|
|
void PNGAPI
|
|
png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
|
|
{
|
|
png_debug(1, "in png_set_gamma");
|
|
if (png_ptr == NULL) return;
|
|
if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
|
|
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
|
|
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
|
|
png_ptr->transformations |= PNG_GAMMA;
|
|
png_ptr->gamma = (float)file_gamma;
|
|
png_ptr->screen_gamma = (float)scrn_gamma;
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
/* Expand paletted images to RGB, expand grayscale images of
|
|
* less than 8-bit depth to 8-bit depth, and expand tRNS chunks
|
|
* to alpha channels.
|
|
*/
|
|
void PNGAPI
|
|
png_set_expand(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_set_expand");
|
|
if (png_ptr == NULL) return;
|
|
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
|
}
|
|
|
|
/* GRR 19990627: the following three functions currently are identical
|
|
* to png_set_expand(). However, it is entirely reasonable that someone
|
|
* might wish to expand an indexed image to RGB but *not* expand a single,
|
|
* fully transparent palette entry to a full alpha channel--perhaps instead
|
|
* convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
|
|
* the transparent color with a particular RGB value, or drop tRNS entirely.
|
|
* IOW, a future version of the library may make the transformations flag
|
|
* a bit more fine-grained, with separate bits for each of these three
|
|
* functions.
|
|
*
|
|
* More to the point, these functions make it obvious what libpng will be
|
|
* doing, whereas "expand" can (and does) mean any number of things.
|
|
*
|
|
* GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified
|
|
* to expand only the sample depth but not to expand the tRNS to alpha.
|
|
*/
|
|
|
|
/* Expand paletted images to RGB. */
|
|
void PNGAPI
|
|
png_set_palette_to_rgb(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_set_palette_to_rgb");
|
|
if (png_ptr == NULL) return;
|
|
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
|
}
|
|
|
|
#if !defined(PNG_1_0_X)
|
|
/* Expand grayscale images of less than 8-bit depth to 8 bits. */
|
|
void PNGAPI
|
|
png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
|
|
if (png_ptr == NULL) return;
|
|
png_ptr->transformations |= PNG_EXPAND;
|
|
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
|
|
/* Expand grayscale images of less than 8-bit depth to 8 bits. */
|
|
/* Deprecated as of libpng-1.2.9 */
|
|
void PNGAPI
|
|
png_set_gray_1_2_4_to_8(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_set_gray_1_2_4_to_8");
|
|
if (png_ptr == NULL) return;
|
|
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
}
|
|
#endif
|
|
|
|
|
|
/* Expand tRNS chunks to alpha channels. */
|
|
void PNGAPI
|
|
png_set_tRNS_to_alpha(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_set_tRNS_to_alpha");
|
|
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
|
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
|
}
|
|
#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
void PNGAPI
|
|
png_set_gray_to_rgb(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_set_gray_to_rgb");
|
|
png_ptr->transformations |= PNG_GRAY_TO_RGB;
|
|
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
|
|
#if defined(PNG_FLOATING_POINT_SUPPORTED)
|
|
/* Convert a RGB image to a grayscale of the same width. This allows us,
|
|
* for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
|
|
*/
|
|
|
|
void PNGAPI
|
|
png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
|
|
double green)
|
|
{
|
|
int red_fixed = (int)((float)red*100000.0 + 0.5);
|
|
int green_fixed = (int)((float)green*100000.0 + 0.5);
|
|
if (png_ptr == NULL) return;
|
|
png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
|
|
}
|
|
#endif
|
|
|
|
void PNGAPI
|
|
png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
|
|
png_fixed_point red, png_fixed_point green)
|
|
{
|
|
png_debug(1, "in png_set_rgb_to_gray");
|
|
if (png_ptr == NULL) return;
|
|
switch(error_action)
|
|
{
|
|
case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
|
|
break;
|
|
case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
|
|
break;
|
|
case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
|
|
}
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
png_ptr->transformations |= PNG_EXPAND;
|
|
#else
|
|
{
|
|
png_warning(png_ptr,
|
|
"Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
|
|
png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
|
|
}
|
|
#endif
|
|
{
|
|
png_uint_16 red_int, green_int;
|
|
if (red < 0 || green < 0)
|
|
{
|
|
red_int = 6968; /* .212671 * 32768 + .5 */
|
|
green_int = 23434; /* .715160 * 32768 + .5 */
|
|
}
|
|
else if (red + green < 100000L)
|
|
{
|
|
red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
|
|
green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
|
|
}
|
|
else
|
|
{
|
|
png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
|
|
red_int = 6968;
|
|
green_int = 23434;
|
|
}
|
|
png_ptr->rgb_to_gray_red_coeff = red_int;
|
|
png_ptr->rgb_to_gray_green_coeff = green_int;
|
|
png_ptr->rgb_to_gray_blue_coeff =
|
|
(png_uint_16)(32768 - red_int - green_int);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
|
|
defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
|
|
defined(PNG_LEGACY_SUPPORTED)
|
|
void PNGAPI
|
|
png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
|
|
read_user_transform_fn)
|
|
{
|
|
png_debug(1, "in png_set_read_user_transform_fn");
|
|
if (png_ptr == NULL) return;
|
|
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
|
|
png_ptr->transformations |= PNG_USER_TRANSFORM;
|
|
png_ptr->read_user_transform_fn = read_user_transform_fn;
|
|
#endif
|
|
#ifdef PNG_LEGACY_SUPPORTED
|
|
if (read_user_transform_fn)
|
|
png_warning(png_ptr,
|
|
"This version of libpng does not support user transforms");
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
/* Initialize everything needed for the read. This includes modifying
|
|
* the palette.
|
|
*/
|
|
void /* PRIVATE */
|
|
png_init_read_transformations(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_init_read_transformations");
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
if (png_ptr != NULL)
|
|
#endif
|
|
{
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \
|
|
|| defined(PNG_READ_GAMMA_SUPPORTED)
|
|
int color_type = png_ptr->color_type;
|
|
#endif
|
|
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
/* Detect gray background and attempt to enable optimization
|
|
* for gray --> RGB case */
|
|
/* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
|
|
* RGB_ALPHA (in which case need_expand is superfluous anyway), the
|
|
* background color might actually be gray yet not be flagged as such.
|
|
* This is not a problem for the current code, which uses
|
|
* PNG_BACKGROUND_IS_GRAY only to decide when to do the
|
|
* png_do_gray_to_rgb() transformation.
|
|
*/
|
|
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
|
|
!(color_type & PNG_COLOR_MASK_COLOR))
|
|
{
|
|
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
|
} else if ((png_ptr->transformations & PNG_BACKGROUND) &&
|
|
!(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
|
|
(png_ptr->transformations & PNG_GRAY_TO_RGB) &&
|
|
png_ptr->background.red == png_ptr->background.green &&
|
|
png_ptr->background.red == png_ptr->background.blue)
|
|
{
|
|
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
|
png_ptr->background.gray = png_ptr->background.red;
|
|
}
|
|
#endif
|
|
|
|
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
|
|
(png_ptr->transformations & PNG_EXPAND))
|
|
{
|
|
if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
|
|
{
|
|
/* expand background and tRNS chunks */
|
|
switch (png_ptr->bit_depth)
|
|
{
|
|
case 1:
|
|
png_ptr->background.gray *= (png_uint_16)0xff;
|
|
png_ptr->background.red = png_ptr->background.green
|
|
= png_ptr->background.blue = png_ptr->background.gray;
|
|
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
|
|
{
|
|
png_ptr->trans_values.gray *= (png_uint_16)0xff;
|
|
png_ptr->trans_values.red = png_ptr->trans_values.green
|
|
= png_ptr->trans_values.blue = png_ptr->trans_values.gray;
|
|
}
|
|
break;
|
|
case 2:
|
|
png_ptr->background.gray *= (png_uint_16)0x55;
|
|
png_ptr->background.red = png_ptr->background.green
|
|
= png_ptr->background.blue = png_ptr->background.gray;
|
|
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
|
|
{
|
|
png_ptr->trans_values.gray *= (png_uint_16)0x55;
|
|
png_ptr->trans_values.red = png_ptr->trans_values.green
|
|
= png_ptr->trans_values.blue = png_ptr->trans_values.gray;
|
|
}
|
|
break;
|
|
case 4:
|
|
png_ptr->background.gray *= (png_uint_16)0x11;
|
|
png_ptr->background.red = png_ptr->background.green
|
|
= png_ptr->background.blue = png_ptr->background.gray;
|
|
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
|
|
{
|
|
png_ptr->trans_values.gray *= (png_uint_16)0x11;
|
|
png_ptr->trans_values.red = png_ptr->trans_values.green
|
|
= png_ptr->trans_values.blue = png_ptr->trans_values.gray;
|
|
}
|
|
break;
|
|
case 8:
|
|
case 16:
|
|
png_ptr->background.red = png_ptr->background.green
|
|
= png_ptr->background.blue = png_ptr->background.gray;
|
|
break;
|
|
}
|
|
}
|
|
else if (color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
png_ptr->background.red =
|
|
png_ptr->palette[png_ptr->background.index].red;
|
|
png_ptr->background.green =
|
|
png_ptr->palette[png_ptr->background.index].green;
|
|
png_ptr->background.blue =
|
|
png_ptr->palette[png_ptr->background.index].blue;
|
|
|
|
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_INVERT_ALPHA)
|
|
{
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
|
|
#endif
|
|
{
|
|
/* invert the alpha channel (in tRNS) unless the pixels are
|
|
going to be expanded, in which case leave it for later */
|
|
int i, istop;
|
|
istop=(int)png_ptr->num_trans;
|
|
for (i=0; i<istop; i++)
|
|
png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
|
|
png_ptr->background_1 = png_ptr->background;
|
|
#endif
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
|
|
|
|
if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
|
|
&& (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
|
|
< PNG_GAMMA_THRESHOLD))
|
|
{
|
|
int i, k;
|
|
k=0;
|
|
for (i=0; i<png_ptr->num_trans; i++)
|
|
{
|
|
if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
|
|
k=1; /* partial transparency is present */
|
|
}
|
|
if (k == 0)
|
|
png_ptr->transformations &= ~PNG_GAMMA;
|
|
}
|
|
|
|
if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
|
|
png_ptr->gamma != 0.0)
|
|
{
|
|
png_build_gamma_table(png_ptr);
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_BACKGROUND)
|
|
{
|
|
if (color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
/* could skip if no transparency and
|
|
*/
|
|
png_color back, back_1;
|
|
png_colorp palette = png_ptr->palette;
|
|
int num_palette = png_ptr->num_palette;
|
|
int i;
|
|
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
|
|
{
|
|
back.red = png_ptr->gamma_table[png_ptr->background.red];
|
|
back.green = png_ptr->gamma_table[png_ptr->background.green];
|
|
back.blue = png_ptr->gamma_table[png_ptr->background.blue];
|
|
|
|
back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
|
|
back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
|
|
back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
|
|
}
|
|
else
|
|
{
|
|
double g, gs;
|
|
|
|
switch (png_ptr->background_gamma_type)
|
|
{
|
|
case PNG_BACKGROUND_GAMMA_SCREEN:
|
|
g = (png_ptr->screen_gamma);
|
|
gs = 1.0;
|
|
break;
|
|
case PNG_BACKGROUND_GAMMA_FILE:
|
|
g = 1.0 / (png_ptr->gamma);
|
|
gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
|
|
break;
|
|
case PNG_BACKGROUND_GAMMA_UNIQUE:
|
|
g = 1.0 / (png_ptr->background_gamma);
|
|
gs = 1.0 / (png_ptr->background_gamma *
|
|
png_ptr->screen_gamma);
|
|
break;
|
|
default:
|
|
g = 1.0; /* back_1 */
|
|
gs = 1.0; /* back */
|
|
}
|
|
|
|
if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
|
|
{
|
|
back.red = (png_byte)png_ptr->background.red;
|
|
back.green = (png_byte)png_ptr->background.green;
|
|
back.blue = (png_byte)png_ptr->background.blue;
|
|
}
|
|
else
|
|
{
|
|
back.red = (png_byte)(pow(
|
|
(double)png_ptr->background.red/255, gs) * 255.0 + .5);
|
|
back.green = (png_byte)(pow(
|
|
(double)png_ptr->background.green/255, gs) * 255.0 + .5);
|
|
back.blue = (png_byte)(pow(
|
|
(double)png_ptr->background.blue/255, gs) * 255.0 + .5);
|
|
}
|
|
|
|
back_1.red = (png_byte)(pow(
|
|
(double)png_ptr->background.red/255, g) * 255.0 + .5);
|
|
back_1.green = (png_byte)(pow(
|
|
(double)png_ptr->background.green/255, g) * 255.0 + .5);
|
|
back_1.blue = (png_byte)(pow(
|
|
(double)png_ptr->background.blue/255, g) * 255.0 + .5);
|
|
}
|
|
for (i = 0; i < num_palette; i++)
|
|
{
|
|
if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
|
|
{
|
|
if (png_ptr->trans[i] == 0)
|
|
{
|
|
palette[i] = back;
|
|
}
|
|
else /* if (png_ptr->trans[i] != 0xff) */
|
|
{
|
|
png_byte v, w;
|
|
|
|
v = png_ptr->gamma_to_1[palette[i].red];
|
|
png_composite(w, v, png_ptr->trans[i], back_1.red);
|
|
palette[i].red = png_ptr->gamma_from_1[w];
|
|
|
|
v = png_ptr->gamma_to_1[palette[i].green];
|
|
png_composite(w, v, png_ptr->trans[i], back_1.green);
|
|
palette[i].green = png_ptr->gamma_from_1[w];
|
|
|
|
v = png_ptr->gamma_to_1[palette[i].blue];
|
|
png_composite(w, v, png_ptr->trans[i], back_1.blue);
|
|
palette[i].blue = png_ptr->gamma_from_1[w];
|
|
}
|
|
}
|
|
else
|
|
{
|
|
palette[i].red = png_ptr->gamma_table[palette[i].red];
|
|
palette[i].green = png_ptr->gamma_table[palette[i].green];
|
|
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
|
}
|
|
}
|
|
/* Prevent the transformations being done again, and make sure
|
|
* that the now spurious alpha channel is stripped - the code
|
|
* has just reduced background composition and gamma correction
|
|
* to a simple alpha channel strip.
|
|
*/
|
|
png_ptr->transformations &= ~PNG_BACKGROUND;
|
|
png_ptr->transformations &= ~PNG_GAMMA;
|
|
png_ptr->transformations |= PNG_STRIP_ALPHA;
|
|
}
|
|
/* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
|
|
else
|
|
/* color_type != PNG_COLOR_TYPE_PALETTE */
|
|
{
|
|
double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1);
|
|
double g = 1.0;
|
|
double gs = 1.0;
|
|
|
|
switch (png_ptr->background_gamma_type)
|
|
{
|
|
case PNG_BACKGROUND_GAMMA_SCREEN:
|
|
g = (png_ptr->screen_gamma);
|
|
gs = 1.0;
|
|
break;
|
|
case PNG_BACKGROUND_GAMMA_FILE:
|
|
g = 1.0 / (png_ptr->gamma);
|
|
gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
|
|
break;
|
|
case PNG_BACKGROUND_GAMMA_UNIQUE:
|
|
g = 1.0 / (png_ptr->background_gamma);
|
|
gs = 1.0 / (png_ptr->background_gamma *
|
|
png_ptr->screen_gamma);
|
|
break;
|
|
}
|
|
|
|
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);
|
|
|
|
if ((png_ptr->background.red != png_ptr->background.green) ||
|
|
(png_ptr->background.red != png_ptr->background.blue) ||
|
|
(png_ptr->background.red != png_ptr->background.gray))
|
|
{
|
|
/* RGB or RGBA with color background */
|
|
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
|
|
{
|
|
/* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
|
|
png_ptr->background_1.red = png_ptr->background_1.green
|
|
= png_ptr->background_1.blue = png_ptr->background_1.gray;
|
|
png_ptr->background.red = png_ptr->background.green
|
|
= png_ptr->background.blue = png_ptr->background.gray;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
/* transformation does not include PNG_BACKGROUND */
|
|
#endif /* PNG_READ_BACKGROUND_SUPPORTED */
|
|
if (color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
png_colorp palette = png_ptr->palette;
|
|
int num_palette = png_ptr->num_palette;
|
|
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];
|
|
}
|
|
|
|
/* Done the gamma correction. */
|
|
png_ptr->transformations &= ~PNG_GAMMA;
|
|
}
|
|
}
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
else
|
|
#endif
|
|
#endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
/* No GAMMA transformation */
|
|
if ((png_ptr->transformations & PNG_BACKGROUND) &&
|
|
(color_type == PNG_COLOR_TYPE_PALETTE))
|
|
{
|
|
int i;
|
|
int istop = (int)png_ptr->num_trans;
|
|
png_color back;
|
|
png_colorp palette = png_ptr->palette;
|
|
|
|
back.red = (png_byte)png_ptr->background.red;
|
|
back.green = (png_byte)png_ptr->background.green;
|
|
back.blue = (png_byte)png_ptr->background.blue;
|
|
|
|
for (i = 0; i < istop; i++)
|
|
{
|
|
if (png_ptr->trans[i] == 0)
|
|
{
|
|
palette[i] = back;
|
|
}
|
|
else if (png_ptr->trans[i] != 0xff)
|
|
{
|
|
/* The png_composite() macro is defined in png.h */
|
|
png_composite(palette[i].red, palette[i].red,
|
|
png_ptr->trans[i], back.red);
|
|
png_composite(palette[i].green, palette[i].green,
|
|
png_ptr->trans[i], back.green);
|
|
png_composite(palette[i].blue, palette[i].blue,
|
|
png_ptr->trans[i], back.blue);
|
|
}
|
|
}
|
|
|
|
/* Handled alpha, still need to strip the channel. */
|
|
png_ptr->transformations &= ~PNG_BACKGROUND;
|
|
png_ptr->transformations |= PNG_STRIP_ALPHA;
|
|
}
|
|
#endif /* PNG_READ_BACKGROUND_SUPPORTED */
|
|
|
|
#if defined(PNG_READ_SHIFT_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_SHIFT) &&
|
|
(color_type == PNG_COLOR_TYPE_PALETTE))
|
|
{
|
|
png_uint_16 i;
|
|
png_uint_16 istop = png_ptr->num_palette;
|
|
int sr = 8 - png_ptr->sig_bit.red;
|
|
int sg = 8 - png_ptr->sig_bit.green;
|
|
int sb = 8 - png_ptr->sig_bit.blue;
|
|
|
|
if (sr < 0 || sr > 8)
|
|
sr = 0;
|
|
if (sg < 0 || sg > 8)
|
|
sg = 0;
|
|
if (sb < 0 || sb > 8)
|
|
sb = 0;
|
|
for (i = 0; i < istop; i++)
|
|
{
|
|
png_ptr->palette[i].red >>= sr;
|
|
png_ptr->palette[i].green >>= sg;
|
|
png_ptr->palette[i].blue >>= sb;
|
|
}
|
|
}
|
|
#endif /* PNG_READ_SHIFT_SUPPORTED */
|
|
}
|
|
#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
|
|
&& !defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr)
|
|
return;
|
|
#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 /* PRIVATE */
|
|
png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
|
|
{
|
|
png_debug(1, "in png_read_transform_info");
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_EXPAND)
|
|
{
|
|
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
if (png_ptr->num_trans &&
|
|
(png_ptr->transformations & PNG_EXPAND_tRNS))
|
|
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->num_trans)
|
|
{
|
|
if (png_ptr->transformations & PNG_EXPAND_tRNS)
|
|
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
|
|
#if 0 /* Removed from libpng-1.2.27 */
|
|
else
|
|
info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
|
|
#endif
|
|
}
|
|
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_GAMMA_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_GAMMA)
|
|
{
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED
|
|
info_ptr->gamma = png_ptr->gamma;
|
|
#endif
|
|
#ifdef PNG_FIXED_POINT_SUPPORTED
|
|
info_ptr->int_gamma = png_ptr->int_gamma;
|
|
#endif
|
|
}
|
|
#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_GRAY_TO_RGB_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_GRAY_TO_RGB)
|
|
info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
|
|
#endif
|
|
|
|
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_RGB_TO_GRAY)
|
|
info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
|
|
#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 (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 defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
|
|
if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
|
|
info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
|
|
#endif
|
|
|
|
if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
|
|
info_ptr->channels++;
|
|
|
|
#if defined(PNG_READ_FILLER_SUPPORTED)
|
|
/* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
|
|
if ((png_ptr->transformations & PNG_FILLER) &&
|
|
((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
|
|
(info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
|
|
{
|
|
info_ptr->channels++;
|
|
/* if adding a true alpha channel not just filler */
|
|
#if !defined(PNG_1_0_X)
|
|
if (png_ptr->transformations & PNG_ADD_ALPHA)
|
|
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
|
|
defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_USER_TRANSFORM)
|
|
{
|
|
if (info_ptr->bit_depth < png_ptr->user_transform_depth)
|
|
info_ptr->bit_depth = png_ptr->user_transform_depth;
|
|
if (info_ptr->channels < png_ptr->user_transform_channels)
|
|
info_ptr->channels = png_ptr->user_transform_channels;
|
|
}
|
|
#endif
|
|
|
|
info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
|
|
info_ptr->bit_depth);
|
|
|
|
info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
|
|
|
|
#if !defined(PNG_READ_EXPAND_SUPPORTED)
|
|
if (png_ptr)
|
|
return;
|
|
#endif
|
|
}
|
|
|
|
/* Transform the row. The order of transformations is significant,
|
|
* and is very touchy. If you add a transformation, take care to
|
|
* decide how it fits in with the other transformations here.
|
|
*/
|
|
void /* PRIVATE */
|
|
png_do_read_transformations(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_do_read_transformations");
|
|
if (png_ptr->row_buf == NULL)
|
|
{
|
|
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
|
|
char msg[50];
|
|
|
|
png_snprintf2(msg, 50,
|
|
"NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,
|
|
png_ptr->pass);
|
|
png_error(png_ptr, msg);
|
|
#else
|
|
png_error(png_ptr, "NULL row buffer");
|
|
#endif
|
|
}
|
|
#ifdef PNG_WARN_UNINITIALIZED_ROW
|
|
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
|
|
/* Application has failed to call either png_read_start_image()
|
|
* or png_read_update_info() after setting transforms that expand
|
|
* pixels. This check added to libpng-1.2.19 */
|
|
#if (PNG_WARN_UNINITIALIZED_ROW==1)
|
|
png_error(png_ptr, "Uninitialized row");
|
|
#else
|
|
png_warning(png_ptr, "Uninitialized row");
|
|
#endif
|
|
#endif
|
|
|
|
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_EXPAND)
|
|
{
|
|
if (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->num_trans &&
|
|
(png_ptr->transformations & PNG_EXPAND_tRNS))
|
|
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_STRIP_ALPHA_SUPPORTED)
|
|
if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
|
|
png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));
|
|
#endif
|
|
|
|
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_RGB_TO_GRAY)
|
|
{
|
|
int rgb_error =
|
|
png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
if (rgb_error)
|
|
{
|
|
png_ptr->rgb_to_gray_status=1;
|
|
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
|
|
PNG_RGB_TO_GRAY_WARN)
|
|
png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
|
|
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
|
|
PNG_RGB_TO_GRAY_ERR)
|
|
png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
From Andreas Dilger e-mail to png-implement, 26 March 1998:
|
|
|
|
In most cases, the "simple transparency" should be done prior to doing
|
|
gray-to-RGB, or you will have to test 3x as many bytes to check if a
|
|
pixel is transparent. You would also need to make sure that the
|
|
transparency information is upgraded to RGB.
|
|
|
|
To summarize, the current flow is:
|
|
- Gray + simple transparency -> compare 1 or 2 gray bytes and composite
|
|
with background "in place" if transparent,
|
|
convert to RGB if necessary
|
|
- Gray + alpha -> composite with gray background and remove alpha bytes,
|
|
convert to RGB if necessary
|
|
|
|
To support RGB backgrounds for gray images we need:
|
|
- Gray + simple transparency -> convert to RGB + simple transparency, compare
|
|
3 or 6 bytes and composite with background
|
|
"in place" if transparent (3x compare/pixel
|
|
compared to doing composite with gray bkgrnd)
|
|
- Gray + alpha -> convert to RGB + alpha, composite with background and
|
|
remove alpha bytes (3x float operations/pixel
|
|
compared with composite on gray background)
|
|
|
|
Greg's change will do this. The reason it wasn't done before is for
|
|
performance, as this increases the per-pixel operations. If we would check
|
|
in advance if the background was gray or RGB, and position the gray-to-RGB
|
|
transform appropriately, then it would save a lot of work/time.
|
|
*/
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
/* if gray -> RGB, do so now only if background is non-gray; else do later
|
|
* for performance reasons */
|
|
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
|
|
!(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
|
|
png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_BACKGROUND) &&
|
|
((png_ptr->num_trans != 0 ) ||
|
|
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
|
|
png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
&(png_ptr->trans_values), &(png_ptr->background)
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
, &(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
|
|
);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if ((png_ptr->transformations & PNG_GAMMA) &&
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
!((png_ptr->transformations & PNG_BACKGROUND) &&
|
|
((png_ptr->num_trans != 0) ||
|
|
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
|
|
#endif
|
|
(png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
|
|
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_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
|
|
png_ptr->palette_lookup, png_ptr->dither_index);
|
|
if (png_ptr->row_info.rowbytes == (png_uint_32)0)
|
|
png_error(png_ptr, "png_do_dither returned rowbytes=0");
|
|
}
|
|
#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_PACKSWAP_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_PACKSWAP)
|
|
png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
/* if gray -> RGB, do so now only if we did not do so above */
|
|
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
|
|
(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
|
|
png_do_gray_to_rgb(&(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_uint_32)png_ptr->filler, png_ptr->flags);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_INVERT_ALPHA)
|
|
png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
|
|
#endif
|
|
|
|
#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_SWAP_ALPHA)
|
|
png_do_read_swap_alpha(&(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_USER_TRANSFORM_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_USER_TRANSFORM)
|
|
{
|
|
if (png_ptr->read_user_transform_fn != NULL)
|
|
(*(png_ptr->read_user_transform_fn)) /* user read transform function */
|
|
(png_ptr, /* png_ptr */
|
|
&(png_ptr->row_info), /* row_info: */
|
|
/* png_uint_32 width; width of row */
|
|
/* png_uint_32 rowbytes; number of bytes in row */
|
|
/* png_byte color_type; color type of pixels */
|
|
/* png_byte bit_depth; bit depth of samples */
|
|
/* png_byte channels; number of channels (1-4) */
|
|
/* png_byte pixel_depth; bits per pixel (depth*channels) */
|
|
png_ptr->row_buf + 1); /* start of pixel data for row */
|
|
#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
|
|
if (png_ptr->user_transform_depth)
|
|
png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
|
|
if (png_ptr->user_transform_channels)
|
|
png_ptr->row_info.channels = png_ptr->user_transform_channels;
|
|
#endif
|
|
png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
|
|
png_ptr->row_info.channels);
|
|
png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
|
|
png_ptr->row_info.width);
|
|
}
|
|
#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 /* PRIVATE */
|
|
png_do_unpack(png_row_infop row_info, png_bytep row)
|
|
{
|
|
png_debug(1, "in png_do_unpack");
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
if (row != NULL && row_info != NULL && row_info->bit_depth < 8)
|
|
#else
|
|
if (row_info->bit_depth < 8)
|
|
#endif
|
|
{
|
|
png_uint_32 i;
|
|
png_uint_32 row_width=row_info->width;
|
|
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
|
|
png_bytep dp = row + (png_size_t)row_width - 1;
|
|
png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*dp = (png_byte)((*sp >> shift) & 0x01);
|
|
if (shift == 7)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift++;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
|
|
png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
|
|
png_bytep dp = row + (png_size_t)row_width - 1;
|
|
png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*dp = (png_byte)((*sp >> shift) & 0x03);
|
|
if (shift == 6)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 2;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
|
|
png_bytep dp = row + (png_size_t)row_width - 1;
|
|
png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*dp = (png_byte)((*sp >> shift) & 0x0f);
|
|
if (shift == 4)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift = 4;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
|
row_info->rowbytes = row_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 /* PRIVATE */
|
|
png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
|
|
{
|
|
png_debug(1, "in png_do_unshift");
|
|
if (
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL && sig_bits != NULL &&
|
|
#endif
|
|
row_info->color_type != PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
int shift[4];
|
|
int channels = 0;
|
|
int c;
|
|
png_uint_16 value = 0;
|
|
png_uint_32 row_width = row_info->width;
|
|
|
|
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;
|
|
}
|
|
|
|
for (c = 0; c < channels; c++)
|
|
{
|
|
if (shift[c] <= 0)
|
|
shift[c] = 0;
|
|
else
|
|
value = 1;
|
|
}
|
|
|
|
if (!value)
|
|
return;
|
|
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 2:
|
|
{
|
|
png_bytep bp;
|
|
png_uint_32 i;
|
|
png_uint_32 istop = row_info->rowbytes;
|
|
|
|
for (bp = row, i = 0; i < istop; i++)
|
|
{
|
|
*bp >>= 1;
|
|
*bp++ &= 0x55;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
png_bytep bp = row;
|
|
png_uint_32 i;
|
|
png_uint_32 istop = row_info->rowbytes;
|
|
png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) |
|
|
(png_byte)((int)0xf >> shift[0]));
|
|
|
|
for (i = 0; i < istop; i++)
|
|
{
|
|
*bp >>= shift[0];
|
|
*bp++ &= mask;
|
|
}
|
|
break;
|
|
}
|
|
case 8:
|
|
{
|
|
png_bytep bp = row;
|
|
png_uint_32 i;
|
|
png_uint_32 istop = row_width * channels;
|
|
|
|
for (i = 0; i < istop; i++)
|
|
{
|
|
*bp++ >>= shift[i%channels];
|
|
}
|
|
break;
|
|
}
|
|
case 16:
|
|
{
|
|
png_bytep bp = row;
|
|
png_uint_32 i;
|
|
png_uint_32 istop = channels * row_width;
|
|
|
|
for (i = 0; i < istop; i++)
|
|
{
|
|
value = (png_uint_16)((*bp << 8) + *(bp + 1));
|
|
value >>= shift[i%channels];
|
|
*bp++ = (png_byte)(value >> 8);
|
|
*bp++ = (png_byte)(value & 0xff);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_16_TO_8_SUPPORTED)
|
|
/* chop rows of bit depth 16 down to 8 */
|
|
void /* PRIVATE */
|
|
png_do_chop(png_row_infop row_info, png_bytep row)
|
|
{
|
|
png_debug(1, "in png_do_chop");
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
if (row != NULL && row_info != NULL && row_info->bit_depth == 16)
|
|
#else
|
|
if (row_info->bit_depth == 16)
|
|
#endif
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
png_uint_32 i;
|
|
png_uint_32 istop = row_info->width * row_info->channels;
|
|
|
|
for (i = 0; i<istop; i++, sp += 2, dp++)
|
|
{
|
|
#if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED)
|
|
/* This does a more accurate scaling of the 16-bit color
|
|
* value, rather than a simple low-byte truncation.
|
|
*
|
|
* What the ideal calculation should be:
|
|
* *dp = (((((png_uint_32)(*sp) << 8) |
|
|
* (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L;
|
|
*
|
|
* GRR: no, I think this is what it really should be:
|
|
* *dp = (((((png_uint_32)(*sp) << 8) |
|
|
* (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L;
|
|
*
|
|
* GRR: here's the exact calculation with shifts:
|
|
* temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L;
|
|
* *dp = (temp - (temp >> 8)) >> 8;
|
|
*
|
|
* Approximate calculation with shift/add instead of multiply/divide:
|
|
* *dp = ((((png_uint_32)(*sp) << 8) |
|
|
* (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8;
|
|
*
|
|
* What we actually do to avoid extra shifting and conversion:
|
|
*/
|
|
|
|
*dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);
|
|
#else
|
|
/* Simply discard the low order byte */
|
|
*dp = *sp;
|
|
#endif
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = (png_byte)(8 * row_info->channels);
|
|
row_info->rowbytes = row_info->width * row_info->channels;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
|
|
void /* PRIVATE */
|
|
png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
|
|
{
|
|
png_debug(1, "in png_do_read_swap_alpha");
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
if (row != NULL && row_info != NULL)
|
|
#endif
|
|
{
|
|
png_uint_32 row_width = row_info->width;
|
|
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
{
|
|
/* This converts from RGBA to ARGB */
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_byte save;
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
save = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = save;
|
|
}
|
|
}
|
|
/* This converts from RRGGBBAA to AARRGGBB */
|
|
else
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_byte save[2];
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
save[0] = *(--sp);
|
|
save[1] = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = save[0];
|
|
*(--dp) = save[1];
|
|
}
|
|
}
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
{
|
|
/* This converts from GA to AG */
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_byte save;
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
save = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = save;
|
|
}
|
|
}
|
|
/* This converts from GGAA to AAGG */
|
|
else
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_byte save[2];
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
save[0] = *(--sp);
|
|
save[1] = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = save[0];
|
|
*(--dp) = save[1];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
|
|
void /* PRIVATE */
|
|
png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
|
|
{
|
|
png_debug(1, "in png_do_read_invert_alpha");
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
if (row != NULL && row_info != NULL)
|
|
#endif
|
|
{
|
|
png_uint_32 row_width = row_info->width;
|
|
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
{
|
|
/* This inverts the alpha channel in RGBA */
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
|
/* This does nothing:
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
We can replace it with:
|
|
*/
|
|
sp-=3;
|
|
dp=sp;
|
|
}
|
|
}
|
|
/* This inverts the alpha channel in RRGGBBAA */
|
|
else
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = (png_byte)(255 - *(--sp));
|
|
*(--dp) = (png_byte)(255 - *(--sp));
|
|
|
|
/* This does nothing:
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
We can replace it with:
|
|
*/
|
|
sp-=6;
|
|
dp=sp;
|
|
}
|
|
}
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
{
|
|
/* This inverts the alpha channel in GA */
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = (png_byte)(255 - *(--sp));
|
|
*(--dp) = *(--sp);
|
|
}
|
|
}
|
|
/* This inverts the alpha channel in GGAA */
|
|
else
|
|
{
|
|
png_bytep sp = row + row_info->rowbytes;
|
|
png_bytep dp = sp;
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = (png_byte)(255 - *(--sp));
|
|
*(--dp) = (png_byte)(255 - *(--sp));
|
|
/*
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*/
|
|
sp-=2;
|
|
dp=sp;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_FILLER_SUPPORTED)
|
|
/* Add filler channel if we have RGB color */
|
|
void /* PRIVATE */
|
|
png_do_read_filler(png_row_infop row_info, png_bytep row,
|
|
png_uint_32 filler, png_uint_32 flags)
|
|
{
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = row_info->width;
|
|
|
|
png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
|
|
png_byte lo_filler = (png_byte)(filler & 0xff);
|
|
|
|
png_debug(1, "in png_do_read_filler");
|
|
if (
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL &&
|
|
#endif
|
|
row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
/* This changes the data from G to GX */
|
|
if (flags & PNG_FLAG_FILLER_AFTER)
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width;
|
|
png_bytep dp = sp + (png_size_t)row_width;
|
|
for (i = 1; i < row_width; i++)
|
|
{
|
|
*(--dp) = lo_filler;
|
|
*(--dp) = *(--sp);
|
|
}
|
|
*(--dp) = lo_filler;
|
|
row_info->channels = 2;
|
|
row_info->pixel_depth = 16;
|
|
row_info->rowbytes = row_width * 2;
|
|
}
|
|
/* This changes the data from G to XG */
|
|
else
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width;
|
|
png_bytep dp = sp + (png_size_t)row_width;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = lo_filler;
|
|
}
|
|
row_info->channels = 2;
|
|
row_info->pixel_depth = 16;
|
|
row_info->rowbytes = row_width * 2;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
/* This changes the data from GG to GGXX */
|
|
if (flags & PNG_FLAG_FILLER_AFTER)
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 2;
|
|
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
for (i = 1; i < row_width; i++)
|
|
{
|
|
*(--dp) = hi_filler;
|
|
*(--dp) = lo_filler;
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
}
|
|
*(--dp) = hi_filler;
|
|
*(--dp) = lo_filler;
|
|
row_info->channels = 2;
|
|
row_info->pixel_depth = 32;
|
|
row_info->rowbytes = row_width * 4;
|
|
}
|
|
/* This changes the data from GG to XXGG */
|
|
else
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 2;
|
|
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = hi_filler;
|
|
*(--dp) = lo_filler;
|
|
}
|
|
row_info->channels = 2;
|
|
row_info->pixel_depth = 32;
|
|
row_info->rowbytes = row_width * 4;
|
|
}
|
|
}
|
|
} /* COLOR_TYPE == GRAY */
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
/* This changes the data from RGB to RGBX */
|
|
if (flags & PNG_FLAG_FILLER_AFTER)
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 3;
|
|
png_bytep dp = sp + (png_size_t)row_width;
|
|
for (i = 1; i < row_width; i++)
|
|
{
|
|
*(--dp) = lo_filler;
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
}
|
|
*(--dp) = lo_filler;
|
|
row_info->channels = 4;
|
|
row_info->pixel_depth = 32;
|
|
row_info->rowbytes = row_width * 4;
|
|
}
|
|
/* This changes the data from RGB to XRGB */
|
|
else
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 3;
|
|
png_bytep dp = sp + (png_size_t)row_width;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = lo_filler;
|
|
}
|
|
row_info->channels = 4;
|
|
row_info->pixel_depth = 32;
|
|
row_info->rowbytes = row_width * 4;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
/* This changes the data from RRGGBB to RRGGBBXX */
|
|
if (flags & PNG_FLAG_FILLER_AFTER)
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 6;
|
|
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
for (i = 1; i < row_width; i++)
|
|
{
|
|
*(--dp) = hi_filler;
|
|
*(--dp) = lo_filler;
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
}
|
|
*(--dp) = hi_filler;
|
|
*(--dp) = lo_filler;
|
|
row_info->channels = 4;
|
|
row_info->pixel_depth = 64;
|
|
row_info->rowbytes = row_width * 8;
|
|
}
|
|
/* This changes the data from RRGGBB to XXRRGGBB */
|
|
else
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 6;
|
|
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = *(--sp);
|
|
*(--dp) = hi_filler;
|
|
*(--dp) = lo_filler;
|
|
}
|
|
row_info->channels = 4;
|
|
row_info->pixel_depth = 64;
|
|
row_info->rowbytes = row_width * 8;
|
|
}
|
|
}
|
|
} /* COLOR_TYPE == RGB */
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
|
/* expand grayscale files to RGB, with or without alpha */
|
|
void /* PRIVATE */
|
|
png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
|
|
{
|
|
png_uint_32 i;
|
|
png_uint_32 row_width = row_info->width;
|
|
|
|
png_debug(1, "in png_do_gray_to_rgb");
|
|
if (row_info->bit_depth >= 8 &&
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL &&
|
|
#endif
|
|
!(row_info->color_type & PNG_COLOR_MASK_COLOR))
|
|
{
|
|
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width - 1;
|
|
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(dp--) = *sp;
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp--);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 2 - 1;
|
|
png_bytep dp = sp + (png_size_t)row_width * 4;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *(sp--);
|
|
}
|
|
}
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 2 - 1;
|
|
png_bytep dp = sp + (png_size_t)row_width * 2;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp--);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
png_bytep sp = row + (png_size_t)row_width * 4 - 1;
|
|
png_bytep dp = sp + (png_size_t)row_width * 4;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *sp;
|
|
*(dp--) = *(sp - 1);
|
|
*(dp--) = *(sp--);
|
|
*(dp--) = *(sp--);
|
|
}
|
|
}
|
|
}
|
|
row_info->channels += (png_byte)2;
|
|
row_info->color_type |= PNG_COLOR_MASK_COLOR;
|
|
row_info->pixel_depth = (png_byte)(row_info->channels *
|
|
row_info->bit_depth);
|
|
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
|
|
/* reduce RGB files to grayscale, with or without alpha
|
|
* using the equation given in Poynton's ColorFAQ at
|
|
* <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008)
|
|
* New link:
|
|
* <http://www.poynton.com/notes/colour_and_gamma/>
|
|
* Charles Poynton poynton at poynton.com
|
|
*
|
|
* Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
|
|
*
|
|
* We approximate this with
|
|
*
|
|
* Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
|
|
*
|
|
* which can be expressed with integers as
|
|
*
|
|
* Y = (6969 * R + 23434 * G + 2365 * B)/32768
|
|
*
|
|
* The calculation is to be done in a linear colorspace.
|
|
*
|
|
* Other integer coefficents can be used via png_set_rgb_to_gray().
|
|
*/
|
|
int /* PRIVATE */
|
|
png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
|
|
|
|
{
|
|
png_uint_32 i;
|
|
|
|
png_uint_32 row_width = row_info->width;
|
|
int rgb_error = 0;
|
|
|
|
png_debug(1, "in png_do_rgb_to_gray");
|
|
if (
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL &&
|
|
#endif
|
|
(row_info->color_type & PNG_COLOR_MASK_COLOR))
|
|
{
|
|
png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
|
|
png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
|
|
png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
|
|
|
|
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_byte red = png_ptr->gamma_to_1[*(sp++)];
|
|
png_byte green = png_ptr->gamma_to_1[*(sp++)];
|
|
png_byte blue = png_ptr->gamma_to_1[*(sp++)];
|
|
if (red != green || red != blue)
|
|
{
|
|
rgb_error |= 1;
|
|
*(dp++) = png_ptr->gamma_from_1[
|
|
(rc*red + gc*green + bc*blue)>>15];
|
|
}
|
|
else
|
|
*(dp++) = *(sp - 1);
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_byte red = *(sp++);
|
|
png_byte green = *(sp++);
|
|
png_byte blue = *(sp++);
|
|
if (red != green || red != blue)
|
|
{
|
|
rgb_error |= 1;
|
|
*(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
|
|
}
|
|
else
|
|
*(dp++) = *(sp - 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
else /* RGB bit_depth == 16 */
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr->gamma_16_to_1 != NULL &&
|
|
png_ptr->gamma_16_from_1 != NULL)
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 red, green, blue, w;
|
|
|
|
red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
|
|
if (red == green && red == blue)
|
|
w = red;
|
|
else
|
|
{
|
|
png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
|
|
png_ptr->gamma_shift][red>>8];
|
|
png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
|
|
png_ptr->gamma_shift][green>>8];
|
|
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
|
|
png_ptr->gamma_shift][blue>>8];
|
|
png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
|
|
+ bc*blue_1)>>15);
|
|
w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
|
|
png_ptr->gamma_shift][gray16 >> 8];
|
|
rgb_error |= 1;
|
|
}
|
|
|
|
*(dp++) = (png_byte)((w>>8) & 0xff);
|
|
*(dp++) = (png_byte)(w & 0xff);
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 red, green, blue, gray16;
|
|
|
|
red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
|
|
if (red != green || red != blue)
|
|
rgb_error |= 1;
|
|
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
|
|
*(dp++) = (png_byte)((gray16>>8) & 0xff);
|
|
*(dp++) = (png_byte)(gray16 & 0xff);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_byte red = png_ptr->gamma_to_1[*(sp++)];
|
|
png_byte green = png_ptr->gamma_to_1[*(sp++)];
|
|
png_byte blue = png_ptr->gamma_to_1[*(sp++)];
|
|
if (red != green || red != blue)
|
|
rgb_error |= 1;
|
|
*(dp++) = png_ptr->gamma_from_1
|
|
[(rc*red + gc*green + bc*blue)>>15];
|
|
*(dp++) = *(sp++); /* alpha */
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_byte red = *(sp++);
|
|
png_byte green = *(sp++);
|
|
png_byte blue = *(sp++);
|
|
if (red != green || red != blue)
|
|
rgb_error |= 1;
|
|
*(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
|
|
*(dp++) = *(sp++); /* alpha */
|
|
}
|
|
}
|
|
}
|
|
else /* RGBA bit_depth == 16 */
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr->gamma_16_to_1 != NULL &&
|
|
png_ptr->gamma_16_from_1 != NULL)
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 red, green, blue, w;
|
|
|
|
red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
|
|
|
|
if (red == green && red == blue)
|
|
w = red;
|
|
else
|
|
{
|
|
png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
|
|
png_ptr->gamma_shift][red>>8];
|
|
png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
|
|
png_ptr->gamma_shift][green>>8];
|
|
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
|
|
png_ptr->gamma_shift][blue>>8];
|
|
png_uint_16 gray16 = (png_uint_16)((rc * red_1
|
|
+ gc * green_1 + bc * blue_1)>>15);
|
|
w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
|
|
png_ptr->gamma_shift][gray16 >> 8];
|
|
rgb_error |= 1;
|
|
}
|
|
|
|
*(dp++) = (png_byte)((w>>8) & 0xff);
|
|
*(dp++) = (png_byte)(w & 0xff);
|
|
*(dp++) = *(sp++); /* alpha */
|
|
*(dp++) = *(sp++);
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
png_bytep sp = row;
|
|
png_bytep dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 red, green, blue, gray16;
|
|
red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
|
|
green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
|
|
blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
|
|
if (red != green || red != blue)
|
|
rgb_error |= 1;
|
|
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
|
|
*(dp++) = (png_byte)((gray16>>8) & 0xff);
|
|
*(dp++) = (png_byte)(gray16 & 0xff);
|
|
*(dp++) = *(sp++); /* alpha */
|
|
*(dp++) = *(sp++);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
row_info->channels -= (png_byte)2;
|
|
row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
|
|
row_info->pixel_depth = (png_byte)(row_info->channels *
|
|
row_info->bit_depth);
|
|
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
}
|
|
return rgb_error;
|
|
}
|
|
#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 PNGAPI
|
|
png_build_grayscale_palette(int bit_depth, png_colorp palette)
|
|
{
|
|
int num_palette;
|
|
int color_inc;
|
|
int i;
|
|
int v;
|
|
|
|
png_debug(1, "in png_do_build_grayscale_palette");
|
|
if (palette == NULL)
|
|
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;
|
|
color_inc = 0;
|
|
break;
|
|
}
|
|
|
|
for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
|
|
{
|
|
palette[i].red = (png_byte)v;
|
|
palette[i].green = (png_byte)v;
|
|
palette[i].blue = (png_byte)v;
|
|
}
|
|
}
|
|
|
|
/* This function is currently unused. Do we really need it? */
|
|
#if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED)
|
|
void /* PRIVATE */
|
|
png_correct_palette(png_structp png_ptr, png_colorp palette,
|
|
int num_palette)
|
|
{
|
|
png_debug(1, "in png_correct_palette");
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
|
|
defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
|
|
if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
|
|
{
|
|
png_color back, back_1;
|
|
|
|
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
|
|
{
|
|
back.red = png_ptr->gamma_table[png_ptr->background.red];
|
|
back.green = png_ptr->gamma_table[png_ptr->background.green];
|
|
back.blue = png_ptr->gamma_table[png_ptr->background.blue];
|
|
|
|
back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
|
|
back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
|
|
back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
|
|
}
|
|
else
|
|
{
|
|
double g;
|
|
|
|
g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
|
|
|
|
if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN ||
|
|
fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
|
|
{
|
|
back.red = png_ptr->background.red;
|
|
back.green = png_ptr->background.green;
|
|
back.blue = png_ptr->background.blue;
|
|
}
|
|
else
|
|
{
|
|
back.red =
|
|
(png_byte)(pow((double)png_ptr->background.red/255, g) *
|
|
255.0 + 0.5);
|
|
back.green =
|
|
(png_byte)(pow((double)png_ptr->background.green/255, g) *
|
|
255.0 + 0.5);
|
|
back.blue =
|
|
(png_byte)(pow((double)png_ptr->background.blue/255, g) *
|
|
255.0 + 0.5);
|
|
}
|
|
|
|
g = 1.0 / png_ptr->background_gamma;
|
|
|
|
back_1.red =
|
|
(png_byte)(pow((double)png_ptr->background.red/255, g) *
|
|
255.0 + 0.5);
|
|
back_1.green =
|
|
(png_byte)(pow((double)png_ptr->background.green/255, g) *
|
|
255.0 + 0.5);
|
|
back_1.blue =
|
|
(png_byte)(pow((double)png_ptr->background.blue/255, g) *
|
|
255.0 + 0.5);
|
|
}
|
|
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
png_uint_32 i;
|
|
|
|
for (i = 0; i < (png_uint_32)num_palette; i++)
|
|
{
|
|
if (i < png_ptr->num_trans && png_ptr->trans[i] == 0)
|
|
{
|
|
palette[i] = back;
|
|
}
|
|
else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff)
|
|
{
|
|
png_byte v, w;
|
|
|
|
v = png_ptr->gamma_to_1[png_ptr->palette[i].red];
|
|
png_composite(w, v, png_ptr->trans[i], back_1.red);
|
|
palette[i].red = png_ptr->gamma_from_1[w];
|
|
|
|
v = png_ptr->gamma_to_1[png_ptr->palette[i].green];
|
|
png_composite(w, v, png_ptr->trans[i], back_1.green);
|
|
palette[i].green = png_ptr->gamma_from_1[w];
|
|
|
|
v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];
|
|
png_composite(w, v, png_ptr->trans[i], back_1.blue);
|
|
palette[i].blue = png_ptr->gamma_from_1[w];
|
|
}
|
|
else
|
|
{
|
|
palette[i].red = png_ptr->gamma_table[palette[i].red];
|
|
palette[i].green = png_ptr->gamma_table[palette[i].green];
|
|
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < num_palette; i++)
|
|
{
|
|
if (palette[i].red == (png_byte)png_ptr->trans_values.gray)
|
|
{
|
|
palette[i] = 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
|
|
#endif
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
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];
|
|
}
|
|
}
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
else
|
|
#endif
|
|
#endif
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
if (png_ptr->transformations & PNG_BACKGROUND)
|
|
{
|
|
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
png_color back;
|
|
|
|
back.red = (png_byte)png_ptr->background.red;
|
|
back.green = (png_byte)png_ptr->background.green;
|
|
back.blue = (png_byte)png_ptr->background.blue;
|
|
|
|
for (i = 0; i < (int)png_ptr->num_trans; i++)
|
|
{
|
|
if (png_ptr->trans[i] == 0)
|
|
{
|
|
palette[i].red = back.red;
|
|
palette[i].green = back.green;
|
|
palette[i].blue = back.blue;
|
|
}
|
|
else if (png_ptr->trans[i] != 0xff)
|
|
{
|
|
png_composite(palette[i].red, png_ptr->palette[i].red,
|
|
png_ptr->trans[i], back.red);
|
|
png_composite(palette[i].green, png_ptr->palette[i].green,
|
|
png_ptr->trans[i], back.green);
|
|
png_composite(palette[i].blue, png_ptr->palette[i].blue,
|
|
png_ptr->trans[i], back.blue);
|
|
}
|
|
}
|
|
}
|
|
else /* assume grayscale palette (what else could it be?) */
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < num_palette; i++)
|
|
{
|
|
if (i == (png_byte)png_ptr->trans_values.gray)
|
|
{
|
|
palette[i].red = (png_byte)png_ptr->background.red;
|
|
palette[i].green = (png_byte)png_ptr->background.green;
|
|
palette[i].blue = (png_byte)png_ptr->background.blue;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
|
/* Replace any alpha or transparency with the supplied background color.
|
|
* "background" is already in the screen gamma, while "background_1" is
|
|
* at a gamma of 1.0. Paletted files have already been taken care of.
|
|
*/
|
|
void /* PRIVATE */
|
|
png_do_background(png_row_infop row_info, png_bytep row,
|
|
png_color_16p trans_values, png_color_16p background
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
, png_color_16p background_1,
|
|
png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
|
|
png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
|
|
png_uint_16pp gamma_16_to_1, int gamma_shift
|
|
#endif
|
|
)
|
|
{
|
|
png_bytep sp, dp;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width=row_info->width;
|
|
int shift;
|
|
|
|
png_debug(1, "in png_do_background");
|
|
if (background != NULL &&
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL &&
|
|
#endif
|
|
(!(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_width; i++)
|
|
{
|
|
if ((png_uint_16)((*sp >> shift) & 0x01)
|
|
== trans_values->gray)
|
|
{
|
|
*sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
|
|
*sp |= (png_byte)(background->gray << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 7;
|
|
sp++;
|
|
}
|
|
else
|
|
shift--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_table != NULL)
|
|
{
|
|
sp = row;
|
|
shift = 6;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if ((png_uint_16)((*sp >> shift) & 0x03)
|
|
== trans_values->gray)
|
|
{
|
|
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
|
|
*sp |= (png_byte)(background->gray << shift);
|
|
}
|
|
else
|
|
{
|
|
png_byte p = (png_byte)((*sp >> shift) & 0x03);
|
|
png_byte g = (png_byte)((gamma_table [p | (p << 2) |
|
|
(p << 4) | (p << 6)] >> 6) & 0x03);
|
|
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
|
|
*sp |= (png_byte)(g << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 6;
|
|
sp++;
|
|
}
|
|
else
|
|
shift -= 2;
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
shift = 6;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if ((png_uint_16)((*sp >> shift) & 0x03)
|
|
== trans_values->gray)
|
|
{
|
|
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
|
|
*sp |= (png_byte)(background->gray << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 6;
|
|
sp++;
|
|
}
|
|
else
|
|
shift -= 2;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_table != NULL)
|
|
{
|
|
sp = row;
|
|
shift = 4;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if ((png_uint_16)((*sp >> shift) & 0x0f)
|
|
== trans_values->gray)
|
|
{
|
|
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
|
|
*sp |= (png_byte)(background->gray << shift);
|
|
}
|
|
else
|
|
{
|
|
png_byte p = (png_byte)((*sp >> shift) & 0x0f);
|
|
png_byte g = (png_byte)((gamma_table[p |
|
|
(p << 4)] >> 4) & 0x0f);
|
|
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
|
|
*sp |= (png_byte)(g << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 4;
|
|
sp++;
|
|
}
|
|
else
|
|
shift -= 4;
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
shift = 4;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if ((png_uint_16)((*sp >> shift) & 0x0f)
|
|
== trans_values->gray)
|
|
{
|
|
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
|
|
*sp |= (png_byte)(background->gray << shift);
|
|
}
|
|
if (!shift)
|
|
{
|
|
shift = 4;
|
|
sp++;
|
|
}
|
|
else
|
|
shift -= 4;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 8:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_table != NULL)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp++)
|
|
{
|
|
if (*sp == trans_values->gray)
|
|
{
|
|
*sp = (png_byte)background->gray;
|
|
}
|
|
else
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp++)
|
|
{
|
|
if (*sp == trans_values->gray)
|
|
{
|
|
*sp = (png_byte)background->gray;
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case 16:
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16 != NULL)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp += 2)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
if (v == trans_values->gray)
|
|
{
|
|
/* background is already in screen gamma */
|
|
*sp = (png_byte)((background->gray >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(background->gray & 0xff);
|
|
}
|
|
else
|
|
{
|
|
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp += 2)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
if (v == trans_values->gray)
|
|
{
|
|
*sp = (png_byte)((background->gray >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(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 != NULL)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp += 3)
|
|
{
|
|
if (*sp == trans_values->red &&
|
|
*(sp + 1) == trans_values->green &&
|
|
*(sp + 2) == trans_values->blue)
|
|
{
|
|
*sp = (png_byte)background->red;
|
|
*(sp + 1) = (png_byte)background->green;
|
|
*(sp + 2) = (png_byte)background->blue;
|
|
}
|
|
else
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
*(sp + 1) = gamma_table[*(sp + 1)];
|
|
*(sp + 2) = gamma_table[*(sp + 2)];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp += 3)
|
|
{
|
|
if (*sp == trans_values->red &&
|
|
*(sp + 1) == trans_values->green &&
|
|
*(sp + 2) == trans_values->blue)
|
|
{
|
|
*sp = (png_byte)background->red;
|
|
*(sp + 1) = (png_byte)background->green;
|
|
*(sp + 2) = (png_byte)background->blue;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else /* if (row_info->bit_depth == 16) */
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16 != NULL)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp += 6)
|
|
{
|
|
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
|
|
png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
|
|
if (r == trans_values->red && g == trans_values->green &&
|
|
b == trans_values->blue)
|
|
{
|
|
/* background is already in screen gamma */
|
|
*sp = (png_byte)((background->red >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(background->red & 0xff);
|
|
*(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
|
|
*(sp + 3) = (png_byte)(background->green & 0xff);
|
|
*(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
|
|
*(sp + 5) = (png_byte)(background->blue & 0xff);
|
|
}
|
|
else
|
|
{
|
|
png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
*(sp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 3) = (png_byte)(v & 0xff);
|
|
v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
*(sp + 4) = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 5) = (png_byte)(v & 0xff);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp += 6)
|
|
{
|
|
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1));
|
|
png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
|
|
png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
|
|
|
|
if (r == trans_values->red && g == trans_values->green &&
|
|
b == trans_values->blue)
|
|
{
|
|
*sp = (png_byte)((background->red >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(background->red & 0xff);
|
|
*(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
|
|
*(sp + 3) = (png_byte)(background->green & 0xff);
|
|
*(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
|
|
*(sp + 5) = (png_byte)(background->blue & 0xff);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
|
|
gamma_table != NULL)
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 2, dp++)
|
|
{
|
|
png_uint_16 a = *(sp + 1);
|
|
|
|
if (a == 0xff)
|
|
{
|
|
*dp = gamma_table[*sp];
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
/* background is already in screen gamma */
|
|
*dp = (png_byte)background->gray;
|
|
}
|
|
else
|
|
{
|
|
png_byte v, w;
|
|
|
|
v = gamma_to_1[*sp];
|
|
png_composite(w, v, a, background_1->gray);
|
|
*dp = gamma_from_1[w];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 2, dp++)
|
|
{
|
|
png_byte a = *(sp + 1);
|
|
|
|
if (a == 0xff)
|
|
{
|
|
*dp = *sp;
|
|
}
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
else if (a == 0)
|
|
{
|
|
*dp = (png_byte)background->gray;
|
|
}
|
|
else
|
|
{
|
|
png_composite(*dp, *sp, a, background_1->gray);
|
|
}
|
|
#else
|
|
*dp = (png_byte)background->gray;
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
else /* if (png_ptr->bit_depth == 16) */
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
|
|
gamma_16_to_1 != NULL)
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 4, dp += 2)
|
|
{
|
|
png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
|
|
|
|
if (a == (png_uint_16)0xffff)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
}
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
else if (a == 0)
|
|
#else
|
|
else
|
|
#endif
|
|
{
|
|
/* background is already in screen gamma */
|
|
*dp = (png_byte)((background->gray >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(background->gray & 0xff);
|
|
}
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
else
|
|
{
|
|
png_uint_16 g, v, w;
|
|
|
|
g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
|
|
png_composite_16(v, g, a, background_1->gray);
|
|
w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
|
|
*dp = (png_byte)((w >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(w & 0xff);
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 4, dp += 2)
|
|
{
|
|
png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
|
|
if (a == (png_uint_16)0xffff)
|
|
{
|
|
png_memcpy(dp, sp, 2);
|
|
}
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
else if (a == 0)
|
|
#else
|
|
else
|
|
#endif
|
|
{
|
|
*dp = (png_byte)((background->gray >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(background->gray & 0xff);
|
|
}
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
else
|
|
{
|
|
png_uint_16 g, v;
|
|
|
|
g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
png_composite_16(v, g, a, background_1->gray);
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
|
|
gamma_table != NULL)
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 4, dp += 3)
|
|
{
|
|
png_byte 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)
|
|
{
|
|
/* background is already in screen gamma */
|
|
*dp = (png_byte)background->red;
|
|
*(dp + 1) = (png_byte)background->green;
|
|
*(dp + 2) = (png_byte)background->blue;
|
|
}
|
|
else
|
|
{
|
|
png_byte v, w;
|
|
|
|
v = gamma_to_1[*sp];
|
|
png_composite(w, v, a, background_1->red);
|
|
*dp = gamma_from_1[w];
|
|
v = gamma_to_1[*(sp + 1)];
|
|
png_composite(w, v, a, background_1->green);
|
|
*(dp + 1) = gamma_from_1[w];
|
|
v = gamma_to_1[*(sp + 2)];
|
|
png_composite(w, v, a, background_1->blue);
|
|
*(dp + 2) = gamma_from_1[w];
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 4, dp += 3)
|
|
{
|
|
png_byte a = *(sp + 3);
|
|
|
|
if (a == 0xff)
|
|
{
|
|
*dp = *sp;
|
|
*(dp + 1) = *(sp + 1);
|
|
*(dp + 2) = *(sp + 2);
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = (png_byte)background->red;
|
|
*(dp + 1) = (png_byte)background->green;
|
|
*(dp + 2) = (png_byte)background->blue;
|
|
}
|
|
else
|
|
{
|
|
png_composite(*dp, *sp, a, background->red);
|
|
png_composite(*(dp + 1), *(sp + 1), a,
|
|
background->green);
|
|
png_composite(*(dp + 2), *(sp + 2), a,
|
|
background->blue);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else /* if (row_info->bit_depth == 16) */
|
|
{
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
|
|
gamma_16_to_1 != NULL)
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 8, dp += 6)
|
|
{
|
|
png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
|
|
<< 8) + (png_uint_16)(*(sp + 7)));
|
|
if (a == (png_uint_16)0xffff)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
*(dp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 3) = (png_byte)(v & 0xff);
|
|
v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
*(dp + 4) = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 5) = (png_byte)(v & 0xff);
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
/* background is already in screen gamma */
|
|
*dp = (png_byte)((background->red >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(background->red & 0xff);
|
|
*(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
|
|
*(dp + 3) = (png_byte)(background->green & 0xff);
|
|
*(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
|
|
*(dp + 5) = (png_byte)(background->blue & 0xff);
|
|
}
|
|
else
|
|
{
|
|
png_uint_16 v, w, x;
|
|
|
|
v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
|
|
png_composite_16(w, v, a, background_1->red);
|
|
x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
|
|
*dp = (png_byte)((x >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(x & 0xff);
|
|
v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
|
|
png_composite_16(w, v, a, background_1->green);
|
|
x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
|
|
*(dp + 2) = (png_byte)((x >> 8) & 0xff);
|
|
*(dp + 3) = (png_byte)(x & 0xff);
|
|
v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
|
|
png_composite_16(w, v, a, background_1->blue);
|
|
x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
|
|
*(dp + 4) = (png_byte)((x >> 8) & 0xff);
|
|
*(dp + 5) = (png_byte)(x & 0xff);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++, sp += 8, dp += 6)
|
|
{
|
|
png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
|
|
<< 8) + (png_uint_16)(*(sp + 7)));
|
|
if (a == (png_uint_16)0xffff)
|
|
{
|
|
png_memcpy(dp, sp, 6);
|
|
}
|
|
else if (a == 0)
|
|
{
|
|
*dp = (png_byte)((background->red >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(background->red & 0xff);
|
|
*(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
|
|
*(dp + 3) = (png_byte)(background->green & 0xff);
|
|
*(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
|
|
*(dp + 5) = (png_byte)(background->blue & 0xff);
|
|
}
|
|
else
|
|
{
|
|
png_uint_16 v;
|
|
|
|
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
|
|
png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
|
|
+ *(sp + 3));
|
|
png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
|
|
+ *(sp + 5));
|
|
|
|
png_composite_16(v, r, a, background->red);
|
|
*dp = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 1) = (png_byte)(v & 0xff);
|
|
png_composite_16(v, g, a, background->green);
|
|
*(dp + 2) = (png_byte)((v >> 8) & 0xff);
|
|
*(dp + 3) = (png_byte)(v & 0xff);
|
|
png_composite_16(v, b, a, background->blue);
|
|
*(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--;
|
|
row_info->pixel_depth = (png_byte)(row_info->channels *
|
|
row_info->bit_depth);
|
|
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
/* Gamma correct the image, avoiding the alpha channel. Make sure
|
|
* you do this after you deal with the transparency issue on grayscale
|
|
* or RGB images. If your bit depth is 8, use gamma_table, if it
|
|
* is 16, use gamma_16_table and gamma_shift. Build these with
|
|
* build_gamma_table().
|
|
*/
|
|
void /* PRIVATE */
|
|
png_do_gamma(png_row_infop row_info, png_bytep row,
|
|
png_bytep gamma_table, png_uint_16pp gamma_16_table,
|
|
int gamma_shift)
|
|
{
|
|
png_bytep sp;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width=row_info->width;
|
|
|
|
png_debug(1, "in png_do_gamma");
|
|
if (
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL &&
|
|
#endif
|
|
((row_info->bit_depth <= 8 && gamma_table != NULL) ||
|
|
(row_info->bit_depth == 16 && gamma_16_table != NULL)))
|
|
{
|
|
switch (row_info->color_type)
|
|
{
|
|
case PNG_COLOR_TYPE_RGB:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
}
|
|
}
|
|
else /* if (row_info->bit_depth == 16) */
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 v;
|
|
|
|
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 2;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_RGB_ALPHA:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
sp++;
|
|
}
|
|
}
|
|
else /* if (row_info->bit_depth == 16) */
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 2;
|
|
v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 4;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_GRAY_ALPHA:
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
sp += 2;
|
|
}
|
|
}
|
|
else /* if (row_info->bit_depth == 16) */
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 4;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
case PNG_COLOR_TYPE_GRAY:
|
|
{
|
|
if (row_info->bit_depth == 2)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i += 4)
|
|
{
|
|
int a = *sp & 0xc0;
|
|
int b = *sp & 0x30;
|
|
int c = *sp & 0x0c;
|
|
int d = *sp & 0x03;
|
|
|
|
*sp = (png_byte)(
|
|
((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
|
|
((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
|
|
((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
|
|
((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
|
|
sp++;
|
|
}
|
|
}
|
|
if (row_info->bit_depth == 4)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i += 2)
|
|
{
|
|
int msb = *sp & 0xf0;
|
|
int lsb = *sp & 0x0f;
|
|
|
|
*sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
|
|
| (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
|
|
sp++;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 8)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*sp = gamma_table[*sp];
|
|
sp++;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
|
|
*sp = (png_byte)((v >> 8) & 0xff);
|
|
*(sp + 1) = (png_byte)(v & 0xff);
|
|
sp += 2;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#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 /* PRIVATE */
|
|
png_do_expand_palette(png_row_infop row_info, png_bytep row,
|
|
png_colorp palette, png_bytep trans, int num_trans)
|
|
{
|
|
int shift, value;
|
|
png_bytep sp, dp;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width=row_info->width;
|
|
|
|
png_debug(1, "in png_do_expand_palette");
|
|
if (
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL &&
|
|
#endif
|
|
row_info->color_type == PNG_COLOR_TYPE_PALETTE)
|
|
{
|
|
if (row_info->bit_depth < 8)
|
|
{
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
sp = row + (png_size_t)((row_width - 1) >> 3);
|
|
dp = row + (png_size_t)row_width - 1;
|
|
shift = 7 - (int)((row_width + 7) & 0x07);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if ((*sp >> shift) & 0x01)
|
|
*dp = 1;
|
|
else
|
|
*dp = 0;
|
|
if (shift == 7)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift++;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
sp = row + (png_size_t)((row_width - 1) >> 2);
|
|
dp = row + (png_size_t)row_width - 1;
|
|
shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0x03;
|
|
*dp = (png_byte)value;
|
|
if (shift == 6)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 2;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
sp = row + (png_size_t)((row_width - 1) >> 1);
|
|
dp = row + (png_size_t)row_width - 1;
|
|
shift = (int)((row_width & 0x01) << 2);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0x0f;
|
|
*dp = (png_byte)value;
|
|
if (shift == 4)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 4;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 8;
|
|
row_info->rowbytes = row_width;
|
|
}
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 8:
|
|
{
|
|
if (trans != NULL)
|
|
{
|
|
sp = row + (png_size_t)row_width - 1;
|
|
dp = row + (png_size_t)(row_width << 2) - 1;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if ((int)(*sp) >= num_trans)
|
|
*dp-- = 0xff;
|
|
else
|
|
*dp-- = trans[*sp];
|
|
*dp-- = palette[*sp].blue;
|
|
*dp-- = palette[*sp].green;
|
|
*dp-- = palette[*sp].red;
|
|
sp--;
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 32;
|
|
row_info->rowbytes = row_width * 4;
|
|
row_info->color_type = 6;
|
|
row_info->channels = 4;
|
|
}
|
|
else
|
|
{
|
|
sp = row + (png_size_t)row_width - 1;
|
|
dp = row + (png_size_t)(row_width * 3) - 1;
|
|
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
*dp-- = palette[*sp].blue;
|
|
*dp-- = palette[*sp].green;
|
|
*dp-- = palette[*sp].red;
|
|
sp--;
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 24;
|
|
row_info->rowbytes = row_width * 3;
|
|
row_info->color_type = 2;
|
|
row_info->channels = 3;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If the bit depth < 8, it is expanded to 8. Also, if the already
|
|
* expanded transparency value is supplied, an alpha channel is built.
|
|
*/
|
|
void /* PRIVATE */
|
|
png_do_expand(png_row_infop row_info, png_bytep row,
|
|
png_color_16p trans_value)
|
|
{
|
|
int shift, value;
|
|
png_bytep sp, dp;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width=row_info->width;
|
|
|
|
png_debug(1, "in png_do_expand");
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
if (row != NULL && row_info != NULL)
|
|
#endif
|
|
{
|
|
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
|
|
{
|
|
png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
|
|
|
|
if (row_info->bit_depth < 8)
|
|
{
|
|
switch (row_info->bit_depth)
|
|
{
|
|
case 1:
|
|
{
|
|
gray = (png_uint_16)((gray&0x01)*0xff);
|
|
sp = row + (png_size_t)((row_width - 1) >> 3);
|
|
dp = row + (png_size_t)row_width - 1;
|
|
shift = 7 - (int)((row_width + 7) & 0x07);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if ((*sp >> shift) & 0x01)
|
|
*dp = 0xff;
|
|
else
|
|
*dp = 0;
|
|
if (shift == 7)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift++;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 2:
|
|
{
|
|
gray = (png_uint_16)((gray&0x03)*0x55);
|
|
sp = row + (png_size_t)((row_width - 1) >> 2);
|
|
dp = row + (png_size_t)row_width - 1;
|
|
shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0x03;
|
|
*dp = (png_byte)(value | (value << 2) | (value << 4) |
|
|
(value << 6));
|
|
if (shift == 6)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift += 2;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
case 4:
|
|
{
|
|
gray = (png_uint_16)((gray&0x0f)*0x11);
|
|
sp = row + (png_size_t)((row_width - 1) >> 1);
|
|
dp = row + (png_size_t)row_width - 1;
|
|
shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
value = (*sp >> shift) & 0x0f;
|
|
*dp = (png_byte)(value | (value << 4));
|
|
if (shift == 4)
|
|
{
|
|
shift = 0;
|
|
sp--;
|
|
}
|
|
else
|
|
shift = 4;
|
|
|
|
dp--;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
row_info->bit_depth = 8;
|
|
row_info->pixel_depth = 8;
|
|
row_info->rowbytes = row_width;
|
|
}
|
|
|
|
if (trans_value != NULL)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
gray = gray & 0xff;
|
|
sp = row + (png_size_t)row_width - 1;
|
|
dp = row + (png_size_t)(row_width << 1) - 1;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (*sp == gray)
|
|
*dp-- = 0;
|
|
else
|
|
*dp-- = 0xff;
|
|
*dp-- = *sp--;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
png_byte gray_high = (gray >> 8) & 0xff;
|
|
png_byte gray_low = gray & 0xff;
|
|
sp = row + row_info->rowbytes - 1;
|
|
dp = row + (row_info->rowbytes << 1) - 1;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (*(sp - 1) == gray_high && *(sp) == gray_low)
|
|
{
|
|
*dp-- = 0;
|
|
*dp-- = 0;
|
|
}
|
|
else
|
|
{
|
|
*dp-- = 0xff;
|
|
*dp-- = 0xff;
|
|
}
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
}
|
|
}
|
|
row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
|
|
row_info->channels = 2;
|
|
row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
|
|
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
|
|
row_width);
|
|
}
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
|
|
{
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_byte red = trans_value->red & 0xff;
|
|
png_byte green = trans_value->green & 0xff;
|
|
png_byte blue = trans_value->blue & 0xff;
|
|
sp = row + (png_size_t)row_info->rowbytes - 1;
|
|
dp = row + (png_size_t)(row_width << 2) - 1;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
|
|
*dp-- = 0;
|
|
else
|
|
*dp-- = 0xff;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
png_byte red_high = (trans_value->red >> 8) & 0xff;
|
|
png_byte green_high = (trans_value->green >> 8) & 0xff;
|
|
png_byte blue_high = (trans_value->blue >> 8) & 0xff;
|
|
png_byte red_low = trans_value->red & 0xff;
|
|
png_byte green_low = trans_value->green & 0xff;
|
|
png_byte blue_low = trans_value->blue & 0xff;
|
|
sp = row + row_info->rowbytes - 1;
|
|
dp = row + (png_size_t)(row_width << 3) - 1;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
if (*(sp - 5) == red_high &&
|
|
*(sp - 4) == red_low &&
|
|
*(sp - 3) == green_high &&
|
|
*(sp - 2) == green_low &&
|
|
*(sp - 1) == blue_high &&
|
|
*(sp ) == blue_low)
|
|
{
|
|
*dp-- = 0;
|
|
*dp-- = 0;
|
|
}
|
|
else
|
|
{
|
|
*dp-- = 0xff;
|
|
*dp-- = 0xff;
|
|
}
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
*dp-- = *sp--;
|
|
}
|
|
}
|
|
row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
|
row_info->channels = 4;
|
|
row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
|
|
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(PNG_READ_DITHER_SUPPORTED)
|
|
void /* PRIVATE */
|
|
png_do_dither(png_row_infop row_info, png_bytep row,
|
|
png_bytep palette_lookup, png_bytep dither_lookup)
|
|
{
|
|
png_bytep sp, dp;
|
|
png_uint_32 i;
|
|
png_uint_32 row_width=row_info->width;
|
|
|
|
png_debug(1, "in png_do_dither");
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
if (row != NULL && row_info != NULL)
|
|
#endif
|
|
{
|
|
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_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 = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
|
|
palette_lookup != NULL && row_info->bit_depth == 8)
|
|
{
|
|
int r, g, b, p;
|
|
sp = row;
|
|
dp = row;
|
|
for (i = 0; i < row_width; i++)
|
|
{
|
|
r = *sp++;
|
|
g = *sp++;
|
|
b = *sp++;
|
|
sp++;
|
|
|
|
p = (((r >> (8 - PNG_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 = PNG_ROWBYTES(row_info->pixel_depth, row_width);
|
|
}
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
|
|
dither_lookup && row_info->bit_depth == 8)
|
|
{
|
|
sp = row;
|
|
for (i = 0; i < row_width; i++, sp++)
|
|
{
|
|
*sp = dither_lookup[*sp];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifdef PNG_FLOATING_POINT_SUPPORTED
|
|
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
|
static PNG_CONST int png_gamma_shift[] =
|
|
{0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
|
|
|
|
/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
|
|
* tables, we don't make a full table if we are reducing to 8-bit in
|
|
* the future. Note also how the gamma_16 tables are segmented so that
|
|
* we don't need to allocate > 64K chunks for a full 16-bit table.
|
|
*/
|
|
void /* PRIVATE */
|
|
png_build_gamma_table(png_structp png_ptr)
|
|
{
|
|
png_debug(1, "in png_build_gamma_table");
|
|
|
|
if (png_ptr->bit_depth <= 8)
|
|
{
|
|
int i;
|
|
double g;
|
|
|
|
if (png_ptr->screen_gamma > .000001)
|
|
g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
|
|
else
|
|
g = 1.0;
|
|
|
|
png_ptr->gamma_table = (png_bytep)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 defined(PNG_READ_BACKGROUND_SUPPORTED) || \
|
|
defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
|
|
if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))
|
|
{
|
|
|
|
g = 1.0 / (png_ptr->gamma);
|
|
|
|
png_ptr->gamma_to_1 = (png_bytep)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);
|
|
}
|
|
|
|
|
|
png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
|
|
(png_uint_32)256);
|
|
|
|
if (png_ptr->screen_gamma > 0.000001)
|
|
g = 1.0 / png_ptr->screen_gamma;
|
|
else
|
|
g = png_ptr->gamma; /* probably doing rgb_to_gray */
|
|
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
|
|
g) * 255.0 + .5);
|
|
|
|
}
|
|
}
|
|
#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
|
|
}
|
|
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 = (png_byte)shift;
|
|
|
|
num = (1 << (8 - shift));
|
|
|
|
if (png_ptr->screen_gamma > .000001)
|
|
g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
|
|
else
|
|
g = 1.0;
|
|
|
|
png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
|
|
(png_uint_32)(num * png_sizeof(png_uint_16p)));
|
|
|
|
if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
|
|
{
|
|
double fin, fout;
|
|
png_uint_32 last, max;
|
|
|
|
png_memset(png_ptr->gamma_16_table, 0, num * png_sizeof(png_uint_16p));
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
|
|
(png_uint_32)(256 * png_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)((png_uint_32)num << 8));
|
|
while (last <= max)
|
|
{
|
|
png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
|
|
[(int)(last >> (8 - shift))] = (png_uint_16)(
|
|
(png_uint_16)i | ((png_uint_16)i << 8));
|
|
last++;
|
|
}
|
|
}
|
|
while (last < ((png_uint_32)num << 8))
|
|
{
|
|
png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
|
|
[(int)(last >> (8 - shift))] = (png_uint_16)65535L;
|
|
last++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
|
|
(png_uint_32)(256 * png_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 defined(PNG_READ_BACKGROUND_SUPPORTED) || \
|
|
defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
|
|
if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
|
|
{
|
|
|
|
g = 1.0 / (png_ptr->gamma);
|
|
|
|
png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
|
|
(png_uint_32)(num * png_sizeof(png_uint_16p )));
|
|
|
|
png_memset(png_ptr->gamma_16_to_1, 0, num * png_sizeof(png_uint_16p));
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
|
|
(png_uint_32)(256 * png_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);
|
|
}
|
|
}
|
|
|
|
if (png_ptr->screen_gamma > 0.000001)
|
|
g = 1.0 / png_ptr->screen_gamma;
|
|
else
|
|
g = png_ptr->gamma; /* probably doing rgb_to_gray */
|
|
|
|
png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
|
|
(png_uint_32)(num * png_sizeof(png_uint_16p)));
|
|
|
|
png_memset(png_ptr->gamma_16_from_1, 0,
|
|
num * png_sizeof(png_uint_16p));
|
|
|
|
for (i = 0; i < num; i++)
|
|
{
|
|
png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
|
|
(png_uint_32)(256 * png_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 /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
|
|
}
|
|
}
|
|
#endif
|
|
/* To do: install integer version of png_build_gamma_table here */
|
|
#endif
|
|
|
|
#if defined(PNG_MNG_FEATURES_SUPPORTED)
|
|
/* undoes intrapixel differencing */
|
|
void /* PRIVATE */
|
|
png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
|
|
{
|
|
png_debug(1, "in png_do_read_intrapixel");
|
|
if (
|
|
#if defined(PNG_USELESS_TESTS_SUPPORTED)
|
|
row != NULL && row_info != NULL &&
|
|
#endif
|
|
(row_info->color_type & PNG_COLOR_MASK_COLOR))
|
|
{
|
|
int bytes_per_pixel;
|
|
png_uint_32 row_width = row_info->width;
|
|
if (row_info->bit_depth == 8)
|
|
{
|
|
png_bytep rp;
|
|
png_uint_32 i;
|
|
|
|
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
|
|
bytes_per_pixel = 3;
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
bytes_per_pixel = 4;
|
|
else
|
|
return;
|
|
|
|
for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
|
|
{
|
|
*(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff);
|
|
*(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff);
|
|
}
|
|
}
|
|
else if (row_info->bit_depth == 16)
|
|
{
|
|
png_bytep rp;
|
|
png_uint_32 i;
|
|
|
|
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
|
|
bytes_per_pixel = 6;
|
|
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
|
|
bytes_per_pixel = 8;
|
|
else
|
|
return;
|
|
|
|
for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
|
|
{
|
|
png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);
|
|
png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);
|
|
png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);
|
|
png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL);
|
|
png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL);
|
|
*(rp ) = (png_byte)((red >> 8) & 0xff);
|
|
*(rp+1) = (png_byte)(red & 0xff);
|
|
*(rp+4) = (png_byte)((blue >> 8) & 0xff);
|
|
*(rp+5) = (png_byte)(blue & 0xff);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
#endif /* PNG_MNG_FEATURES_SUPPORTED */
|
|
#endif /* PNG_READ_SUPPORTED */
|