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| author | Dimitri van Heesch <dimitri@stack.nl> | 2009-08-14 14:49:07 (GMT) |
|---|---|---|
| committer | Dimitri van Heesch <dimitri@stack.nl> | 2009-08-14 14:49:07 (GMT) |
| commit | 8c6ca30831818a77a6947baad63ab99cb8cd8c31 (patch) | |
| tree | fed426d0d7216311cbd009a1fcd2786176478b5e /libpng/pngrtran.c | |
| parent | 142b4807d2ae7479691bd0800d28364b9857b82f (diff) | |
| download | Doxygen-8c6ca30831818a77a6947baad63ab99cb8cd8c31.zip Doxygen-8c6ca30831818a77a6947baad63ab99cb8cd8c31.tar.gz Doxygen-8c6ca30831818a77a6947baad63ab99cb8cd8c31.tar.bz2 | |
Release-1.5.9-20090814
Diffstat (limited to 'libpng/pngrtran.c')
| -rw-r--r-- | libpng/pngrtran.c | 4284 |
1 files changed, 0 insertions, 4284 deletions
diff --git a/libpng/pngrtran.c b/libpng/pngrtran.c deleted file mode 100644 index cda3921..0000000 --- a/libpng/pngrtran.c +++ /dev/null @@ -1,4284 +0,0 @@ - -/* pngrtran.c - transforms the data in a row for PNG readers - * - * Last changed in libpng 1.2.22 [October 13, 2007] - * For conditions of distribution and use, see copyright notice in png.h - * Copyright (c) 1998-2007 Glenn Randers-Pehrson - * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) - * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) - * - * This file contains functions optionally called by an application - * in order to tell libpng how to handle data when reading a PNG. - * Transformations that are used in both reading and writing are - * in pngtrans.c. - */ - -#define PNG_INTERNAL -#include "png.h" - -#if defined(PNG_READ_SUPPORTED) - -/* Set the action on getting a CRC error for an ancillary or critical chunk. */ -void PNGAPI -png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) -{ - png_debug(1, "in png_set_crc_action\n"); - /* Tell libpng how we react to CRC errors in critical chunks */ - if(png_ptr == NULL) return; - switch (crit_action) - { - case PNG_CRC_NO_CHANGE: /* leave setting as is */ - break; - case PNG_CRC_WARN_USE: /* warn/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; - break; - case PNG_CRC_QUIET_USE: /* quiet/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | - PNG_FLAG_CRC_CRITICAL_IGNORE; - break; - case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */ - png_warning(png_ptr, "Can't discard critical data on CRC error."); - case PNG_CRC_ERROR_QUIT: /* error/quit */ - case PNG_CRC_DEFAULT: - default: - png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; - break; - } - - switch (ancil_action) - { - case PNG_CRC_NO_CHANGE: /* leave setting as is */ - break; - case PNG_CRC_WARN_USE: /* warn/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; - break; - case PNG_CRC_QUIET_USE: /* quiet/use data */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | - PNG_FLAG_CRC_ANCILLARY_NOWARN; - break; - case PNG_CRC_ERROR_QUIT: /* error/quit */ - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; - break; - case PNG_CRC_WARN_DISCARD: /* warn/discard data */ - case PNG_CRC_DEFAULT: - default: - png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; - break; - } -} - -#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ - defined(PNG_FLOATING_POINT_SUPPORTED) -/* handle alpha and tRNS via a background color */ -void PNGAPI -png_set_background(png_structp png_ptr, - png_color_16p background_color, int background_gamma_code, - int need_expand, double background_gamma) -{ - png_debug(1, "in png_set_background\n"); - if(png_ptr == NULL) return; - if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) - { - png_warning(png_ptr, "Application must supply a known background gamma"); - return; - } - - png_ptr->transformations |= PNG_BACKGROUND; - png_memcpy(&(png_ptr->background), background_color, - png_sizeof(png_color_16)); - png_ptr->background_gamma = (float)background_gamma; - png_ptr->background_gamma_type = (png_byte)(background_gamma_code); - png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); -} -#endif - -#if defined(PNG_READ_16_TO_8_SUPPORTED) -/* strip 16 bit depth files to 8 bit depth */ -void PNGAPI -png_set_strip_16(png_structp png_ptr) -{ - png_debug(1, "in png_set_strip_16\n"); - if(png_ptr == NULL) return; - png_ptr->transformations |= PNG_16_TO_8; -} -#endif - -#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) -void PNGAPI -png_set_strip_alpha(png_structp png_ptr) -{ - png_debug(1, "in png_set_strip_alpha\n"); - if(png_ptr == NULL) return; - png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; -} -#endif - -#if defined(PNG_READ_DITHER_SUPPORTED) -/* Dither file to 8 bit. Supply a palette, the current number - * of elements in the palette, the maximum number of elements - * allowed, and a histogram if possible. If the current number - * of colors is greater then the maximum number, the palette will be - * modified to fit in the maximum number. "full_dither" indicates - * whether we need a dithering cube set up for RGB images, or if we - * simply are reducing the number of colors in a paletted image. - */ - -typedef struct png_dsort_struct -{ - struct png_dsort_struct FAR * next; - png_byte left; - png_byte right; -} png_dsort; -typedef png_dsort FAR * png_dsortp; -typedef png_dsort FAR * FAR * png_dsortpp; - -void PNGAPI -png_set_dither(png_structp png_ptr, png_colorp palette, - int num_palette, int maximum_colors, png_uint_16p histogram, - int full_dither) -{ - png_debug(1, "in png_set_dither\n"); - if(png_ptr == NULL) return; - png_ptr->transformations |= PNG_DITHER; - - if (!full_dither) - { - int i; - - png_ptr->dither_index = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * png_sizeof (png_byte))); - for (i = 0; i < num_palette; i++) - png_ptr->dither_index[i] = (png_byte)i; - } - - if (num_palette > maximum_colors) - { - if (histogram != NULL) - { - /* This is easy enough, just throw out the least used colors. - Perhaps not the best solution, but good enough. */ - - int i; - - /* initialize an array to sort colors */ - png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * png_sizeof (png_byte))); - - /* initialize the dither_sort array */ - for (i = 0; i < num_palette; i++) - png_ptr->dither_sort[i] = (png_byte)i; - - /* Find the least used palette entries by starting a - bubble sort, and running it until we have sorted - out enough colors. Note that we don't care about - sorting all the colors, just finding which are - least used. */ - - for (i = num_palette - 1; i >= maximum_colors; i--) - { - int done; /* to stop early if the list is pre-sorted */ - int j; - - done = 1; - for (j = 0; j < i; j++) - { - if (histogram[png_ptr->dither_sort[j]] - < histogram[png_ptr->dither_sort[j + 1]]) - { - png_byte t; - - t = png_ptr->dither_sort[j]; - png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1]; - png_ptr->dither_sort[j + 1] = t; - done = 0; - } - } - if (done) - break; - } - - /* swap the palette around, and set up a table, if necessary */ - if (full_dither) - { - int j = num_palette; - - /* put all the useful colors within the max, but don't - move the others */ - for (i = 0; i < maximum_colors; i++) - { - if ((int)png_ptr->dither_sort[i] >= maximum_colors) - { - do - j--; - while ((int)png_ptr->dither_sort[j] >= maximum_colors); - palette[i] = palette[j]; - } - } - } - else - { - int j = num_palette; - - /* move all the used colors inside the max limit, and - develop a translation table */ - for (i = 0; i < maximum_colors; i++) - { - /* only move the colors we need to */ - if ((int)png_ptr->dither_sort[i] >= maximum_colors) - { - png_color tmp_color; - - do - j--; - while ((int)png_ptr->dither_sort[j] >= maximum_colors); - - tmp_color = palette[j]; - palette[j] = palette[i]; - palette[i] = tmp_color; - /* indicate where the color went */ - png_ptr->dither_index[j] = (png_byte)i; - png_ptr->dither_index[i] = (png_byte)j; - } - } - - /* find closest color for those colors we are not using */ - for (i = 0; i < num_palette; i++) - { - if ((int)png_ptr->dither_index[i] >= maximum_colors) - { - int min_d, k, min_k, d_index; - - /* find the closest color to one we threw out */ - d_index = png_ptr->dither_index[i]; - min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); - for (k = 1, min_k = 0; k < maximum_colors; k++) - { - int d; - - d = PNG_COLOR_DIST(palette[d_index], palette[k]); - - if (d < min_d) - { - min_d = d; - min_k = k; - } - } - /* point to closest color */ - png_ptr->dither_index[i] = (png_byte)min_k; - } - } - } - png_free(png_ptr, png_ptr->dither_sort); - png_ptr->dither_sort=NULL; - } - else - { - /* This is much harder to do simply (and quickly). Perhaps - we need to go through a median cut routine, but those - don't always behave themselves with only a few colors - as input. So we will just find the closest two colors, - and throw out one of them (chosen somewhat randomly). - [We don't understand this at all, so if someone wants to - work on improving it, be our guest - AED, GRP] - */ - int i; - int max_d; - int num_new_palette; - png_dsortp t; - png_dsortpp hash; - - t=NULL; - - /* initialize palette index arrays */ - png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * png_sizeof (png_byte))); - png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, - (png_uint_32)(num_palette * png_sizeof (png_byte))); - - /* initialize the sort array */ - for (i = 0; i < num_palette; i++) - { - png_ptr->index_to_palette[i] = (png_byte)i; - png_ptr->palette_to_index[i] = (png_byte)i; - } - - hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * - png_sizeof (png_dsortp))); - for (i = 0; i < 769; i++) - hash[i] = NULL; -/* png_memset(hash, 0, 769 * png_sizeof (png_dsortp)); */ - - num_new_palette = num_palette; - - /* initial wild guess at how far apart the farthest pixel - pair we will be eliminating will be. Larger - numbers mean more areas will be allocated, Smaller - numbers run the risk of not saving enough data, and - having to do this all over again. - - I have not done extensive checking on this number. - */ - max_d = 96; - - while (num_new_palette > maximum_colors) - { - for (i = 0; i < num_new_palette - 1; i++) - { - int j; - - for (j = i + 1; j < num_new_palette; j++) - { - int d; - - d = PNG_COLOR_DIST(palette[i], palette[j]); - - if (d <= max_d) - { - - t = (png_dsortp)png_malloc_warn(png_ptr, - (png_uint_32)(png_sizeof(png_dsort))); - if (t == NULL) - break; - t->next = hash[d]; - t->left = (png_byte)i; - t->right = (png_byte)j; - hash[d] = t; - } - } - if (t == NULL) - break; - } - - if (t != NULL) - for (i = 0; i <= max_d; i++) - { - if (hash[i] != NULL) - { - png_dsortp p; - - for (p = hash[i]; p; p = p->next) - { - if ((int)png_ptr->index_to_palette[p->left] - < num_new_palette && - (int)png_ptr->index_to_palette[p->right] - < num_new_palette) - { - int j, next_j; - - if (num_new_palette & 0x01) - { - j = p->left; - next_j = p->right; - } - else - { - j = p->right; - next_j = p->left; - } - - num_new_palette--; - palette[png_ptr->index_to_palette[j]] - = palette[num_new_palette]; - if (!full_dither) - { - int k; - - for (k = 0; k < num_palette; k++) - { - if (png_ptr->dither_index[k] == - png_ptr->index_to_palette[j]) - png_ptr->dither_index[k] = - png_ptr->index_to_palette[next_j]; - if ((int)png_ptr->dither_index[k] == - num_new_palette) - png_ptr->dither_index[k] = - png_ptr->index_to_palette[j]; - } - } - - png_ptr->index_to_palette[png_ptr->palette_to_index - [num_new_palette]] = png_ptr->index_to_palette[j]; - png_ptr->palette_to_index[png_ptr->index_to_palette[j]] - = png_ptr->palette_to_index[num_new_palette]; - - png_ptr->index_to_palette[j] = (png_byte)num_new_palette; - png_ptr->palette_to_index[num_new_palette] = (png_byte)j; - } - if (num_new_palette <= maximum_colors) - break; - } - if (num_new_palette <= maximum_colors) - break; - } - } - - for (i = 0; i < 769; i++) - { - if (hash[i] != NULL) - { - png_dsortp p = hash[i]; - while (p) - { - t = p->next; - png_free(png_ptr, p); - p = t; - } - } - hash[i] = 0; - } - max_d += 96; - } - png_free(png_ptr, hash); - png_free(png_ptr, png_ptr->palette_to_index); - png_free(png_ptr, png_ptr->index_to_palette); - png_ptr->palette_to_index=NULL; - png_ptr->index_to_palette=NULL; - } - num_palette = maximum_colors; - } - if (png_ptr->palette == NULL) - { - png_ptr->palette = palette; - } - png_ptr->num_palette = (png_uint_16)num_palette; - - if (full_dither) - { - int i; - png_bytep distance; - int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + - PNG_DITHER_BLUE_BITS; - int num_red = (1 << PNG_DITHER_RED_BITS); - int num_green = (1 << PNG_DITHER_GREEN_BITS); - int num_blue = (1 << PNG_DITHER_BLUE_BITS); - png_size_t num_entries = ((png_size_t)1 << total_bits); - - png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr, - (png_uint_32)(num_entries * png_sizeof (png_byte))); - - png_memset(png_ptr->palette_lookup, 0, num_entries * - png_sizeof (png_byte)); - - distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * - png_sizeof(png_byte))); - - png_memset(distance, 0xff, num_entries * png_sizeof(png_byte)); - - for (i = 0; i < num_palette; i++) - { - int ir, ig, ib; - int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); - int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); - int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); - - for (ir = 0; ir < num_red; ir++) - { - /* int dr = abs(ir - r); */ - int dr = ((ir > r) ? ir - r : r - ir); - int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS)); - - for (ig = 0; ig < num_green; ig++) - { - /* int dg = abs(ig - g); */ - int dg = ((ig > g) ? ig - g : g - ig); - int dt = dr + dg; - int dm = ((dr > dg) ? dr : dg); - int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); - - for (ib = 0; ib < num_blue; ib++) - { - int d_index = index_g | ib; - /* int db = abs(ib - b); */ - int db = ((ib > b) ? ib - b : b - ib); - int dmax = ((dm > db) ? dm : db); - int d = dmax + dt + db; - - if (d < (int)distance[d_index]) - { - distance[d_index] = (png_byte)d; - png_ptr->palette_lookup[d_index] = (png_byte)i; - } - } - } - } - } - - png_free(png_ptr, distance); - } -} -#endif - -#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\n"); - 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\n"); - if(png_ptr == NULL) return; - png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); -#ifdef PNG_WARN_UNINITIALIZED_ROW - png_ptr->flags &= ~PNG_FLAG_ROW_INIT; -#endif -} - -/* 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\n"); - if(png_ptr == NULL) return; - png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); -#ifdef PNG_WARN_UNINITIALIZED_ROW - png_ptr->flags &= ~PNG_FLAG_ROW_INIT; -#endif -} - -#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\n"); - if(png_ptr == NULL) return; - png_ptr->transformations |= PNG_EXPAND; -#ifdef PNG_WARN_UNINITIALIZED_ROW - png_ptr->flags &= ~PNG_FLAG_ROW_INIT; -#endif -} -#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\n"); - 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\n"); - png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); -#ifdef PNG_WARN_UNINITIALIZED_ROW - png_ptr->flags &= ~PNG_FLAG_ROW_INIT; -#endif -} -#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\n"); - png_ptr->transformations |= PNG_GRAY_TO_RGB; -#ifdef PNG_WARN_UNINITIALIZED_ROW - png_ptr->flags &= ~PNG_FLAG_ROW_INIT; -#endif -} -#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\n"); - 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\n"); - 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\n"); -#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]; - } - } - } - /* 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]; - } - } - } -#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); - } - } - } -#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\n"); -#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; - else - info_ptr->color_type |= PNG_COLOR_MASK_COLOR; - } - 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\n"); - 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", 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\n"); -#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\n"); - 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\n"); -#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\n"); -#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\n"); -#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\n"); - 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\n"); - 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/> - * Copyright (c) 1998-01-04 Charles Poynton poynton at inforamp.net - * - * 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\n"); - 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\n"); - 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\n"); -#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\n"); - 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\n"); - 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\n"); - 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\n"); -#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\n"); -#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\n"); - - 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; - - 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 ))); - - 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))); - - 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\n"); - 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 */ |