| |
| /* pngrtran.c - transforms the data in a row for PNG readers |
| * |
| * Last changed in libpng 1.2.45 [July 7, 2011] |
| * Copyright (c) 1998-2011 Glenn Randers-Pehrson |
| * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
| * |
| * This code is released under the libpng license. |
| * For conditions of distribution and use, see the disclaimer |
| * and license in png.h |
| * |
| * This file contains functions optionally called by an application |
| * in order to tell libpng how to handle data when reading a PNG. |
| * Transformations that are used in both reading and writing are |
| * in pngtrans.c. |
| */ |
| |
| #define PNG_INTERNAL |
| #define PNG_NO_PEDANTIC_WARNINGS |
| #include "png.h" |
| #if defined(STARBOARD) |
| # include "starboard/double.h" |
| # define fabs SbDoubleAbsolute |
| # define pow SbDoubleExponent |
| #endif |
| #ifdef PNG_READ_SUPPORTED |
| |
| /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
| void PNGAPI |
| png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) |
| { |
| png_debug(1, "in png_set_crc_action"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| /* Tell libpng how we react to CRC errors in critical chunks */ |
| switch (crit_action) |
| { |
| case PNG_CRC_NO_CHANGE: /* Leave setting as is */ |
| break; |
| |
| case PNG_CRC_WARN_USE: /* Warn/use data */ |
| png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
| png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; |
| break; |
| |
| case PNG_CRC_QUIET_USE: /* Quiet/use data */ |
| png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
| png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | |
| PNG_FLAG_CRC_CRITICAL_IGNORE; |
| break; |
| |
| case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ |
| png_warning(png_ptr, |
| "Can't discard critical data on CRC error."); |
| case PNG_CRC_ERROR_QUIT: /* Error/quit */ |
| |
| case PNG_CRC_DEFAULT: |
| default: |
| png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
| break; |
| } |
| |
| /* Tell libpng how we react to CRC errors in ancillary chunks */ |
| switch (ancil_action) |
| { |
| case PNG_CRC_NO_CHANGE: /* Leave setting as is */ |
| break; |
| |
| case PNG_CRC_WARN_USE: /* Warn/use data */ |
| png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; |
| break; |
| |
| case PNG_CRC_QUIET_USE: /* Quiet/use data */ |
| png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | |
| PNG_FLAG_CRC_ANCILLARY_NOWARN; |
| break; |
| |
| case PNG_CRC_ERROR_QUIT: /* Error/quit */ |
| png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; |
| break; |
| |
| case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ |
| |
| case PNG_CRC_DEFAULT: |
| default: |
| png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| break; |
| } |
| } |
| |
| #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"); |
| |
| 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 |
| |
| #ifdef 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"); |
| |
| if (png_ptr == NULL) |
| return; |
| png_ptr->transformations |= PNG_16_TO_8; |
| } |
| #endif |
| |
| #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED |
| void PNGAPI |
| png_set_strip_alpha(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_strip_alpha"); |
| |
| if (png_ptr == NULL) |
| return; |
| png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; |
| } |
| #endif |
| |
| #ifdef 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"); |
| |
| 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_calloc(png_ptr, (png_uint_32)(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_calloc(png_ptr, |
| (png_uint_32)(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"); |
| |
| 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 |
| |
| #ifdef PNG_READ_EXPAND_SUPPORTED |
| /* Expand paletted images to RGB, expand grayscale images of |
| * less than 8-bit depth to 8-bit depth, and expand tRNS chunks |
| * to alpha channels. |
| */ |
| void PNGAPI |
| png_set_expand(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_expand"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
| png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
| } |
| |
| /* GRR 19990627: the following three functions currently are identical |
| * to png_set_expand(). However, it is entirely reasonable that someone |
| * might wish to expand an indexed image to RGB but *not* expand a single, |
| * fully transparent palette entry to a full alpha channel--perhaps instead |
| * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace |
| * the transparent color with a particular RGB value, or drop tRNS entirely. |
| * IOW, a future version of the library may make the transformations flag |
| * a bit more fine-grained, with separate bits for each of these three |
| * functions. |
| * |
| * More to the point, these functions make it obvious what libpng will be |
| * doing, whereas "expand" can (and does) mean any number of things. |
| * |
| * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified |
| * to expand only the sample depth but not to expand the tRNS to alpha |
| * and its name was changed to png_set_expand_gray_1_2_4_to_8(). |
| */ |
| |
| /* Expand paletted images to RGB. */ |
| void PNGAPI |
| png_set_palette_to_rgb(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_palette_to_rgb"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
| png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
| } |
| |
| #ifndef PNG_1_0_X |
| /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
| void PNGAPI |
| png_set_expand_gray_1_2_4_to_8(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| png_ptr->transformations |= PNG_EXPAND; |
| png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
| } |
| #endif |
| |
| #if defined(PNG_1_0_X) || defined(PNG_1_2_X) |
| /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
| /* Deprecated as of libpng-1.2.9 */ |
| void PNGAPI |
| png_set_gray_1_2_4_to_8(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_gray_1_2_4_to_8"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
| } |
| #endif |
| |
| |
| /* Expand tRNS chunks to alpha channels. */ |
| void PNGAPI |
| png_set_tRNS_to_alpha(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_tRNS_to_alpha"); |
| |
| png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
| png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
| } |
| #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ |
| |
| #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
| void PNGAPI |
| png_set_gray_to_rgb(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_gray_to_rgb"); |
| |
| png_ptr->transformations |= PNG_GRAY_TO_RGB; |
| png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
| } |
| #endif |
| |
| #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
| #ifdef PNG_FLOATING_POINT_SUPPORTED |
| /* Convert a RGB image to a grayscale of the same width. This allows us, |
| * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. |
| */ |
| |
| void PNGAPI |
| png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, |
| double green) |
| { |
| int red_fixed, green_fixed; |
| if (png_ptr == NULL) |
| return; |
| if (red > 21474.83647 || red < -21474.83648 || |
| green > 21474.83647 || green < -21474.83648) |
| { |
| png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); |
| red_fixed = -1; |
| green_fixed = -1; |
| } |
| else |
| { |
| red_fixed = (int)((float)red*100000.0 + 0.5); |
| green_fixed = (int)((float)green*100000.0 + 0.5); |
| } |
| png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed); |
| } |
| #endif |
| |
| void PNGAPI |
| png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, |
| png_fixed_point red, png_fixed_point green) |
| { |
| png_debug(1, "in png_set_rgb_to_gray"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| switch(error_action) |
| { |
| case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY; |
| break; |
| |
| case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; |
| break; |
| |
| case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; |
| } |
| if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| #ifdef 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_LEGACY_SUPPORTED) || \ |
| defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) |
| void PNGAPI |
| png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr |
| read_user_transform_fn) |
| { |
| png_debug(1, "in png_set_read_user_transform_fn"); |
| |
| if (png_ptr == NULL) |
| return; |
| |
| #ifdef 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"); |
| |
| #ifdef 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) |
| |
| #ifdef 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; |
| |
| #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED |
| if (png_ptr->transformations & PNG_INVERT_ALPHA) |
| { |
| #ifdef 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); |
| |
| #ifdef PNG_READ_BACKGROUND_SUPPORTED |
| if (png_ptr->transformations & PNG_BACKGROUND) |
| { |
| if (color_type == PNG_COLOR_TYPE_PALETTE) |
| { |
| /* Could skip if no transparency */ |
| png_color back, back_1; |
| png_colorp palette = png_ptr->palette; |
| int num_palette = png_ptr->num_palette; |
| int i; |
| if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
| { |
| back.red = png_ptr->gamma_table[png_ptr->background.red]; |
| back.green = png_ptr->gamma_table[png_ptr->background.green]; |
| back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
| |
| back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
| back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
| back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
| } |
| else |
| { |
| double g, gs; |
| |
| switch (png_ptr->background_gamma_type) |
| { |
| case PNG_BACKGROUND_GAMMA_SCREEN: |
| g = (png_ptr->screen_gamma); |
| gs = 1.0; |
| break; |
| |
| case PNG_BACKGROUND_GAMMA_FILE: |
| g = 1.0 / (png_ptr->gamma); |
| gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
| break; |
| |
| case PNG_BACKGROUND_GAMMA_UNIQUE: |
| g = 1.0 / (png_ptr->background_gamma); |
| gs = 1.0 / (png_ptr->background_gamma * |
| png_ptr->screen_gamma); |
| break; |
| default: |
| g = 1.0; /* back_1 */ |
| gs = 1.0; /* back */ |
| } |
| |
| if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD) |
| { |
| back.red = (png_byte)png_ptr->background.red; |
| back.green = (png_byte)png_ptr->background.green; |
| back.blue = (png_byte)png_ptr->background.blue; |
| } |
| else |
| { |
| back.red = (png_byte)(pow( |
| (double)png_ptr->background.red/255, gs) * 255.0 + .5); |
| back.green = (png_byte)(pow( |
| (double)png_ptr->background.green/255, gs) * 255.0 |
| + .5); |
| back.blue = (png_byte)(pow( |
| (double)png_ptr->background.blue/255, gs) * 255.0 + .5); |
| } |
| |
| back_1.red = (png_byte)(pow( |
| (double)png_ptr->background.red/255, g) * 255.0 + .5); |
| back_1.green = (png_byte)(pow( |
| (double)png_ptr->background.green/255, g) * 255.0 + .5); |
| back_1.blue = (png_byte)(pow( |
| (double)png_ptr->background.blue/255, g) * 255.0 + .5); |
| } |
| for (i = 0; i < num_palette; i++) |
| { |
| if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
| { |
| if (png_ptr->trans[i] == 0) |
| { |
| palette[i] = back; |
| } |
| else /* if (png_ptr->trans[i] != 0xff) */ |
| { |
| png_byte v, w; |
| |
| v = png_ptr->gamma_to_1[palette[i].red]; |
| png_composite(w, v, png_ptr->trans[i], back_1.red); |
| palette[i].red = png_ptr->gamma_from_1[w]; |
| |
| v = png_ptr->gamma_to_1[palette[i].green]; |
| png_composite(w, v, png_ptr->trans[i], back_1.green); |
| palette[i].green = png_ptr->gamma_from_1[w]; |
| |
| v = png_ptr->gamma_to_1[palette[i].blue]; |
| png_composite(w, v, png_ptr->trans[i], back_1.blue); |
| palette[i].blue = png_ptr->gamma_from_1[w]; |
| } |
| } |
| else |
| { |
| palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| } |
| } |
| /* Prevent the transformations being done again, and make sure |
| * that the now spurious alpha channel is stripped - the code |
| * has just reduced background composition and gamma correction |
| * to a simple alpha channel strip. |
| */ |
| png_ptr->transformations &= ~PNG_BACKGROUND; |
| png_ptr->transformations &= ~PNG_GAMMA; |
| png_ptr->transformations |= PNG_STRIP_ALPHA; |
| } |
| /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ |
| else |
| /* color_type != PNG_COLOR_TYPE_PALETTE */ |
| { |
| double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); |
| double g = 1.0; |
| double gs = 1.0; |
| |
| switch (png_ptr->background_gamma_type) |
| { |
| case PNG_BACKGROUND_GAMMA_SCREEN: |
| g = (png_ptr->screen_gamma); |
| gs = 1.0; |
| break; |
| |
| case PNG_BACKGROUND_GAMMA_FILE: |
| g = 1.0 / (png_ptr->gamma); |
| gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
| break; |
| |
| case PNG_BACKGROUND_GAMMA_UNIQUE: |
| g = 1.0 / (png_ptr->background_gamma); |
| gs = 1.0 / (png_ptr->background_gamma * |
| png_ptr->screen_gamma); |
| break; |
| } |
| |
| png_ptr->background_1.gray = (png_uint_16)(pow( |
| (double)png_ptr->background.gray / m, g) * m + .5); |
| png_ptr->background.gray = (png_uint_16)(pow( |
| (double)png_ptr->background.gray / m, gs) * m + .5); |
| |
| if ((png_ptr->background.red != png_ptr->background.green) || |
| (png_ptr->background.red != png_ptr->background.blue) || |
| (png_ptr->background.red != png_ptr->background.gray)) |
| { |
| /* RGB or RGBA with color background */ |
| png_ptr->background_1.red = (png_uint_16)(pow( |
| (double)png_ptr->background.red / m, g) * m + .5); |
| png_ptr->background_1.green = (png_uint_16)(pow( |
| (double)png_ptr->background.green / m, g) * m + .5); |
| png_ptr->background_1.blue = (png_uint_16)(pow( |
| (double)png_ptr->background.blue / m, g) * m + .5); |
| png_ptr->background.red = (png_uint_16)(pow( |
| (double)png_ptr->background.red / m, gs) * m + .5); |
| png_ptr->background.green = (png_uint_16)(pow( |
| (double)png_ptr->background.green / m, gs) * m + .5); |
| png_ptr->background.blue = (png_uint_16)(pow( |
| (double)png_ptr->background.blue / m, gs) * m + .5); |
| } |
| else |
| { |
| /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ |
| png_ptr->background_1.red = png_ptr->background_1.green |
| = png_ptr->background_1.blue = png_ptr->background_1.gray; |
| png_ptr->background.red = png_ptr->background.green |
| = png_ptr->background.blue = png_ptr->background.gray; |
| } |
| } |
| } |
| else |
| /* Transformation does not include PNG_BACKGROUND */ |
| #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
| if (color_type == PNG_COLOR_TYPE_PALETTE) |
| { |
| png_colorp palette = png_ptr->palette; |
| int num_palette = png_ptr->num_palette; |
| int i; |
| |
| for (i = 0; i < num_palette; i++) |
| { |
| palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| } |
| |
| /* Done the gamma correction. */ |
| png_ptr->transformations &= ~PNG_GAMMA; |
| } |
| } |
| #ifdef PNG_READ_BACKGROUND_SUPPORTED |
| else |
| #endif |
| #endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */ |
| #ifdef PNG_READ_BACKGROUND_SUPPORTED |
| /* No GAMMA transformation */ |
| if ((png_ptr->transformations & PNG_BACKGROUND) && |
| (color_type == PNG_COLOR_TYPE_PALETTE)) |
| { |
| int i; |
| int istop = (int)png_ptr->num_trans; |
| png_color back; |
| png_colorp palette = png_ptr->palette; |
| |
| back.red = (png_byte)png_ptr->background.red; |
| back.green = (png_byte)png_ptr->background.green; |
| back.blue = (png_byte)png_ptr->background.blue; |
| |
| for (i = 0; i < istop; i++) |
| { |
| if (png_ptr->trans[i] == 0) |
| { |
| palette[i] = back; |
| } |
| else if (png_ptr->trans[i] != 0xff) |
| { |
| /* The png_composite() macro is defined in png.h */ |
| png_composite(palette[i].red, palette[i].red, |
| png_ptr->trans[i], back.red); |
| png_composite(palette[i].green, palette[i].green, |
| png_ptr->trans[i], back.green); |
| png_composite(palette[i].blue, palette[i].blue, |
| png_ptr->trans[i], back.blue); |
| } |
| } |
| |
| /* Handled alpha, still need to strip the channel. */ |
| png_ptr->transformations &= ~PNG_BACKGROUND; |
| png_ptr->transformations |= PNG_STRIP_ALPHA; |
| } |
| #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
| |
| #ifdef 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"); |
| |
| #ifdef PNG_READ_EXPAND_SUPPORTED |
| if (png_ptr->transformations & PNG_EXPAND) |
| { |
| if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| { |
| if (png_ptr->num_trans) |
| info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
| else |
| info_ptr->color_type = PNG_COLOR_TYPE_RGB; |
| info_ptr->bit_depth = 8; |
| info_ptr->num_trans = 0; |
| } |
| else |
| { |
| if (png_ptr->num_trans) |
| { |
| if (png_ptr->transformations & PNG_EXPAND_tRNS) |
| info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
| } |
| if (info_ptr->bit_depth < 8) |
| info_ptr->bit_depth = 8; |
| info_ptr->num_trans = 0; |
| } |
| } |
| #endif |
| |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
| if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
| info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
| #endif |
| |
| #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
| if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
| info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; |
| #endif |
| |
| #ifdef 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 |
| |
| #ifdef 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; |
| |
| #ifdef 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++; |
| |
| #ifdef 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 */ |
| #ifndef 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); |
| |
| #ifndef PNG_READ_EXPAND_SUPPORTED |
| if (png_ptr) |
| return; |
| #endif |
| } |
| |
| /* Transform the row. The order of transformations is significant, |
| * and is very touchy. If you add a transformation, take care to |
| * decide how it fits in with the other transformations here. |
| */ |
| void /* PRIVATE */ |
| png_do_read_transformations(png_structp png_ptr) |
| { |
| png_debug(1, "in png_do_read_transformations"); |
| |
| if (png_ptr->row_buf == NULL) |
| { |
| #if defined(PNG_STDIO_SUPPORTED) && !defined(_WIN32_WCE) |
| char msg[50]; |
| |
| png_snprintf2(msg, 50, |
| "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number, |
| png_ptr->pass); |
| png_error(png_ptr, msg); |
| #else |
| png_error(png_ptr, "NULL row buffer"); |
| #endif |
| } |
| #ifdef PNG_WARN_UNINITIALIZED_ROW |
| if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
| /* Application has failed to call either png_read_start_image() |
| * or png_read_update_info() after setting transforms that expand |
| * pixels. This check added to libpng-1.2.19 |
| */ |
| #if (PNG_WARN_UNINITIALIZED_ROW==1) |
| png_error(png_ptr, "Uninitialized row"); |
| #else |
| png_warning(png_ptr, "Uninitialized row"); |
| #endif |
| #endif |
| |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef 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. |
| */ |
| |
| #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
| /* If gray -> RGB, do so now only if background is non-gray; else do later |
| * for performance reasons |
| */ |
| if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
| !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
| png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #endif |
| |
| #ifdef 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) |
| #ifdef 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 |
| |
| #ifdef PNG_READ_GAMMA_SUPPORTED |
| if ((png_ptr->transformations & PNG_GAMMA) && |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef PNG_READ_INVERT_SUPPORTED |
| if (png_ptr->transformations & PNG_INVERT_MONO) |
| png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #endif |
| |
| #ifdef 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 |
| |
| #ifdef PNG_READ_PACK_SUPPORTED |
| if (png_ptr->transformations & PNG_PACK) |
| png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #endif |
| |
| #ifdef PNG_READ_BGR_SUPPORTED |
| if (png_ptr->transformations & PNG_BGR) |
| png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #endif |
| |
| #ifdef PNG_READ_PACKSWAP_SUPPORTED |
| if (png_ptr->transformations & PNG_PACKSWAP) |
| png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #endif |
| |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef 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 |
| |
| #ifdef PNG_READ_SWAP_SUPPORTED |
| if (png_ptr->transformations & PNG_SWAP_BYTES) |
| png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #endif |
| |
| #ifdef 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 */ |
| #ifdef 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 |
| |
| } |
| |
| #ifdef PNG_READ_PACK_SUPPORTED |
| /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
| * without changing the actual values. Thus, if you had a row with |
| * a bit depth of 1, you would end up with bytes that only contained |
| * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
| * png_do_shift() after this. |
| */ |
| void /* PRIVATE */ |
| png_do_unpack(png_row_infop row_info, png_bytep row) |
| { |
| png_debug(1, "in png_do_unpack"); |
| |
| #ifdef 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 |
| |
| #ifdef PNG_READ_SHIFT_SUPPORTED |
| /* Reverse the effects of png_do_shift. This routine merely shifts the |
| * pixels back to their significant bits values. Thus, if you have |
| * a row of bit depth 8, but only 5 are significant, this will shift |
| * the values back to 0 through 31. |
| */ |
| void /* PRIVATE */ |
| png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) |
| { |
| png_debug(1, "in png_do_unshift"); |
| |
| if ( |
| #ifdef 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 |
| |
| #ifdef 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"); |
| |
| #ifdef 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++) |
| { |
| #ifdef 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 |
| |
| #ifdef 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"); |
| |
| #ifdef 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 |
| |
| #ifdef 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"); |
| |
| #ifdef 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 |
| |
| #ifdef PNG_READ_FILLER_SUPPORTED |
| /* Add filler channel if we have RGB color */ |
| void /* PRIVATE */ |
| png_do_read_filler(png_row_infop row_info, png_bytep row, |
| png_uint_32 filler, png_uint_32 flags) |
| { |
| png_uint_32 i; |
| png_uint_32 row_width = row_info->width; |
| |
| png_byte hi_filler = (png_byte)((filler>>8) & 0xff); |
| png_byte lo_filler = (png_byte)(filler & 0xff); |
| |
| png_debug(1, "in png_do_read_filler"); |
| |
| if ( |
| #ifdef 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 |
| |
| #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED |
| /* Expand grayscale files to RGB, with or without alpha */ |
| void /* PRIVATE */ |
| png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
| { |
| png_uint_32 i; |
| png_uint_32 row_width = row_info->width; |
| |
| png_debug(1, "in png_do_gray_to_rgb"); |
| |
| if (row_info->bit_depth >= 8 && |
| #ifdef 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 |
| |
| #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED |
| /* Reduce RGB files to grayscale, with or without alpha |
| * using the equation given in Poynton's ColorFAQ at |
| * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) |
| * New link: |
| * <http://www.poynton.com/notes/colour_and_gamma/> |
| * Charles Poynton poynton at poynton.com |
| * |
| * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B |
| * |
| * We approximate this with |
| * |
| * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B |
| * |
| * which can be expressed with integers as |
| * |
| * Y = (6969 * R + 23434 * G + 2365 * B)/32768 |
| * |
| * The calculation is to be done in a linear colorspace. |
| * |
| * Other integer coefficents can be used via png_set_rgb_to_gray(). |
| */ |
| int /* PRIVATE */ |
| png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) |
| |
| { |
| png_uint_32 i; |
| |
| png_uint_32 row_width = row_info->width; |
| int rgb_error = 0; |
| |
| png_debug(1, "in png_do_rgb_to_gray"); |
| |
| if ( |
| #ifdef PNG_USELESS_TESTS_SUPPORTED |
| row != NULL && row_info != NULL && |
| #endif |
| (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
| { |
| png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; |
| png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; |
| png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; |
| |
| if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| { |
| if (row_info->bit_depth == 8) |
| { |
| #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| |
| for (i = 0; i < row_width; i++) |
| { |
| png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
| png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
| png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
| if (red != green || red != blue) |
| { |
| rgb_error |= 1; |
| *(dp++) = png_ptr->gamma_from_1[ |
| (rc*red + gc*green + bc*blue)>>15]; |
| } |
| else |
| *(dp++) = *(sp - 1); |
| } |
| } |
| else |
| #endif |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| for (i = 0; i < row_width; i++) |
| { |
| png_byte red = *(sp++); |
| png_byte green = *(sp++); |
| png_byte blue = *(sp++); |
| if (red != green || red != blue) |
| { |
| rgb_error |= 1; |
| *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
| } |
| else |
| *(dp++) = *(sp - 1); |
| } |
| } |
| } |
| |
| else /* RGB bit_depth == 16 */ |
| { |
| #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| if (png_ptr->gamma_16_to_1 != NULL && |
| png_ptr->gamma_16_from_1 != NULL) |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| for (i = 0; i < row_width; i++) |
| { |
| png_uint_16 red, green, blue, w; |
| |
| red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| |
| if (red == green && red == blue) |
| w = red; |
| else |
| { |
| png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
| png_ptr->gamma_shift][red>>8]; |
| png_uint_16 green_1 = |
| png_ptr->gamma_16_to_1[(green&0xff) >> |
| png_ptr->gamma_shift][green>>8]; |
| png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
| png_ptr->gamma_shift][blue>>8]; |
| png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 |
| + bc*blue_1)>>15); |
| w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
| png_ptr->gamma_shift][gray16 >> 8]; |
| rgb_error |= 1; |
| } |
| |
| *(dp++) = (png_byte)((w>>8) & 0xff); |
| *(dp++) = (png_byte)(w & 0xff); |
| } |
| } |
| else |
| #endif |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| for (i = 0; i < row_width; i++) |
| { |
| png_uint_16 red, green, blue, gray16; |
| |
| red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| |
| if (red != green || red != blue) |
| rgb_error |= 1; |
| gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
| *(dp++) = (png_byte)((gray16>>8) & 0xff); |
| *(dp++) = (png_byte)(gray16 & 0xff); |
| } |
| } |
| } |
| } |
| if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| { |
| if (row_info->bit_depth == 8) |
| { |
| #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| for (i = 0; i < row_width; i++) |
| { |
| png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
| png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
| png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
| if (red != green || red != blue) |
| rgb_error |= 1; |
| *(dp++) = png_ptr->gamma_from_1 |
| [(rc*red + gc*green + bc*blue)>>15]; |
| *(dp++) = *(sp++); /* alpha */ |
| } |
| } |
| else |
| #endif |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| for (i = 0; i < row_width; i++) |
| { |
| png_byte red = *(sp++); |
| png_byte green = *(sp++); |
| png_byte blue = *(sp++); |
| if (red != green || red != blue) |
| rgb_error |= 1; |
| *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
| *(dp++) = *(sp++); /* alpha */ |
| } |
| } |
| } |
| else /* RGBA bit_depth == 16 */ |
| { |
| #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| if (png_ptr->gamma_16_to_1 != NULL && |
| png_ptr->gamma_16_from_1 != NULL) |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| for (i = 0; i < row_width; i++) |
| { |
| png_uint_16 red, green, blue, w; |
| |
| red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
| |
| if (red == green && red == blue) |
| w = red; |
| else |
| { |
| png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
| png_ptr->gamma_shift][red>>8]; |
| png_uint_16 green_1 = |
| png_ptr->gamma_16_to_1[(green&0xff) >> |
| png_ptr->gamma_shift][green>>8]; |
| png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
| png_ptr->gamma_shift][blue>>8]; |
| png_uint_16 gray16 = (png_uint_16)((rc * red_1 |
| + gc * green_1 + bc * blue_1)>>15); |
| w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
| png_ptr->gamma_shift][gray16 >> 8]; |
| rgb_error |= 1; |
| } |
| |
| *(dp++) = (png_byte)((w>>8) & 0xff); |
| *(dp++) = (png_byte)(w & 0xff); |
| *(dp++) = *(sp++); /* alpha */ |
| *(dp++) = *(sp++); |
| } |
| } |
| else |
| #endif |
| { |
| png_bytep sp = row; |
| png_bytep dp = row; |
| for (i = 0; i < row_width; i++) |
| { |
| png_uint_16 red, green, blue, gray16; |
| red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
| green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
| blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
| if (red != green || red != blue) |
| rgb_error |= 1; |
| gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
| *(dp++) = (png_byte)((gray16>>8) & 0xff); |
| *(dp++) = (png_byte)(gray16 & 0xff); |
| *(dp++) = *(sp++); /* alpha */ |
| *(dp++) = *(sp++); |
| } |
| } |
| } |
| } |
| row_info->channels -= (png_byte)2; |
| row_info->color_type &= ~PNG_COLOR_MASK_COLOR; |
| row_info->pixel_depth = (png_byte)(row_info->channels * |
| row_info->bit_depth); |
| row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
| } |
| return rgb_error; |
| } |
| #endif |
| |
| /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth |
| * large of png_color. This lets grayscale images be treated as |
| * paletted. Most useful for gamma correction and simplification |
| * of code. |
| */ |
| void PNGAPI |
| png_build_grayscale_palette(int bit_depth, png_colorp palette) |
| { |
| int num_palette; |
| int color_inc; |
| int i; |
| int v; |
| |
| png_debug(1, "in png_do_build_grayscale_palette"); |
| |
| if (palette == NULL) |
| return; |
| |
| switch (bit_depth) |
| { |
| case 1: |
| num_palette = 2; |
| color_inc = 0xff; |
| break; |
| |
| case 2: |
| num_palette = 4; |
| color_inc = 0x55; |
| break; |
| |
| case 4: |
| num_palette = 16; |
| color_inc = 0x11; |
| break; |
| |
| case 8: |
| num_palette = 256; |
| color_inc = 1; |
| break; |
| |
| default: |
| num_palette = 0; |
| color_inc = 0; |
| break; |
| } |
| |
| for (i = 0, v = 0; i < num_palette; i++, v += color_inc) |
| { |
| palette[i].red = (png_byte)v; |
| palette[i].green = (png_byte)v; |
| palette[i].blue = (png_byte)v; |
| } |
| } |
| |
| /* This function is currently unused. Do we really need it? */ |
| #if defined(PNG_READ_DITHER_SUPPORTED) && \ |
| defined(PNG_CORRECT_PALETTE_SUPPORTED) |
| void /* PRIVATE */ |
| png_correct_palette(png_structp png_ptr, png_colorp palette, |
| int num_palette) |
| { |
| png_debug(1, "in png_correct_palette"); |
| |
| #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
| defined(PNG_READ_GAMMA_SUPPORTED) && \ |
| defined(PNG_FLOATING_POINT_SUPPORTED) |
| if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND)) |
| { |
| png_color back, back_1; |
| |
| if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
| { |
| back.red = png_ptr->gamma_table[png_ptr->background.red]; |
| back.green = png_ptr->gamma_table[png_ptr->background.green]; |
| back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
| |
| back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
| back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
| back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
| } |
| else |
| { |
| double g; |
| |
| g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); |
| |
| if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN |
| || fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) |
| { |
| back.red = png_ptr->background.red; |
| back.green = png_ptr->background.green; |
| back.blue = png_ptr->background.blue; |
| } |
| else |
| { |
| back.red = |
| (png_byte)(pow((double)png_ptr->background.red/255, g) * |
| 255.0 + 0.5); |
| back.green = |
| (png_byte)(pow((double)png_ptr->background.green/255, g) * |
| 255.0 + 0.5); |
| back.blue = |
| (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
| 255.0 + 0.5); |
| } |
| |
| g = 1.0 / png_ptr->background_gamma; |
| |
| back_1.red = |
| (png_byte)(pow((double)png_ptr->background.red/255, g) * |
| 255.0 + 0.5); |
| back_1.green = |
| (png_byte)(pow((double)png_ptr->background.green/255, g) * |
| 255.0 + 0.5); |
| back_1.blue = |
| (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
| 255.0 + 0.5); |
| } |
| |
| if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| { |
| png_uint_32 i; |
| |
| for (i = 0; i < (png_uint_32)num_palette; i++) |
| { |
| if (i < png_ptr->num_trans && png_ptr->trans[i] == 0) |
| { |
| palette[i] = back; |
| } |
| else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
| { |
| png_byte v, w; |
| |
| v = png_ptr->gamma_to_1[png_ptr->palette[i].red]; |
| png_composite(w, v, png_ptr->trans[i], back_1.red); |
| palette[i].red = png_ptr->gamma_from_1[w]; |
| |
| v = png_ptr->gamma_to_1[png_ptr->palette[i].green]; |
| png_composite(w, v, png_ptr->trans[i], back_1.green); |
| palette[i].green = png_ptr->gamma_from_1[w]; |
| |
| v = png_ptr->gamma_to_1[png_ptr->palette[i].blue]; |
| png_composite(w, v, png_ptr->trans[i], back_1.blue); |
| palette[i].blue = png_ptr->gamma_from_1[w]; |
| } |
| else |
| { |
| palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| } |
| } |
| } |
| else |
| { |
| int i; |
| |
| for (i = 0; i < num_palette; i++) |
| { |
| if (palette[i].red == (png_byte)png_ptr->trans_values.gray) |
| { |
| palette[i] = back; |
| } |
| else |
| { |
| palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| } |
| } |
| } |
| } |
| else |
| #endif |
| #ifdef 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]; |
| } |
| } |
| #ifdef PNG_READ_BACKGROUND_SUPPORTED |
| else |
| #endif |
| #endif |
| #ifdef 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 |
| |
| #ifdef 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 |
| #ifdef PNG_READ_GAMMA_SUPPORTED |
| , png_color_16p background_1, |
| png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, |
| png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, |
| png_uint_16pp gamma_16_to_1, int gamma_shift |
| #endif |
| ) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| png_uint_32 row_width=row_info->width; |
| int shift; |
| |
| png_debug(1, "in png_do_background"); |
| |
| if (background != NULL && |
| #ifdef 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: |
| { |
| #ifdef PNG_READ_GAMMA_SUPPORTED |
| if (gamma_table != NULL) |
| { |
| sp = row; |
| shift = 6; |
| for (i = 0; i < row_width; i++) |
| { |
| if ((png_uint_16)((*sp >> shift) & 0x03) |
| == 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: |
| { |
| #ifdef PNG_READ_GAMMA_SUPPORTED |
| if (gamma_table != NULL) |
| { |
| sp = row; |
| shift = 4; |
| for (i = 0; i < row_width; i++) |
| { |
| if ((png_uint_16 |