| |
| /* pngrtran.c - transforms the data in a row for PNG readers |
| * |
| * libpng 1.00 |
| * For conditions of distribution and use, see copyright notice in png.h |
| * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| * Copyright (c) 1996, 1997 Andreas Dilger |
| * Copyright (c) 1998, Glenn Randers-Pehrson |
| * March 7, 1998 |
| * |
| * This file contains functions optionally called by an application |
| * in order to tell libpng how to handle data when reading a PNG. |
| * Transformations which are used in both reading and writing are |
| * in pngtrans.c. |
| */ |
| |
| #define PNG_INTERNAL |
| #include "png.h" |
| |
| #ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED |
| /* With these routines, we avoid an integer divide, which will be slower on |
| * many machines. However, it does take more operations than the corresponding |
| * divide method, so it may be slower on some RISC systems. There are two |
| * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. |
| * |
| * Note that the rounding factors are NOT supposed to be the same! 128 and |
| * 32768 are correct for the NODIV code; 127 and 32767 are correct for the |
| * standard method. |
| * |
| * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] |
| */ |
| |
| /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ |
| # define png_composite(composite, fg, alpha, bg) \ |
| { png_uint_16 temp = ((png_uint_16)(fg) * (png_uint_16)(alpha) + \ |
| (png_uint_16)(bg)*(png_uint_16)(255 - \ |
| (png_uint_16)(alpha)) + (png_uint_16)128); \ |
| (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } |
| # define png_composite_16(composite, fg, alpha, bg) \ |
| { png_uint_32 temp = ((png_uint_32)(fg) * (png_uint_32)(alpha) + \ |
| (png_uint_32)(bg)*(png_uint_32)(65535L - \ |
| (png_uint_32)(alpha)) + (png_uint_32)32768L); \ |
| (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } |
| |
| #else /* standard method using integer division */ |
| |
| /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ |
| # define png_composite(composite, fg, alpha, bg) \ |
| (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ |
| (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ |
| (png_uint_16)127) / 255) |
| # define png_composite_16(composite, fg, alpha, bg) \ |
| (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ |
| (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \ |
| (png_uint_32)32767) / (png_uint_32)65535L) |
| |
| #endif /* ?PNG_READ_COMPOSITE_NODIV_SUPPORTED */ |
| |
| |
| /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
| void |
| 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 */ |
| 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) |
| /* handle alpha and tRNS via a background color */ |
| void |
| 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 (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, |
| 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 |
| png_set_strip_16(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_strip_16\n"); |
| png_ptr->transformations |= PNG_16_TO_8; |
| } |
| #endif |
| |
| #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
| void |
| png_set_strip_alpha(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_strip_alpha\n"); |
| png_ptr->transformations |= PNG_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 |
| 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"); |
| 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 * 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; |
| png_bytep sort; |
| |
| /* initialize an array to sort colors */ |
| sort = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_palette |
| * sizeof (png_byte))); |
| |
| /* initialize the sort array */ |
| for (i = 0; i < num_palette; i++) |
| 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[sort[j]] < histogram[sort[j + 1]]) |
| { |
| png_byte t; |
| |
| t = sort[j]; |
| sort[j] = sort[j + 1]; |
| 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; |
| |
| /* put all the useful colors within the max, but don't |
| move the others */ |
| for (i = 0, j = num_palette; i < maximum_colors; i++) |
| { |
| if ((int)sort[i] >= maximum_colors) |
| { |
| do |
| j--; |
| while ((int)sort[j] >= maximum_colors); |
| palette[i] = palette[j]; |
| } |
| } |
| } |
| else |
| { |
| int j; |
| |
| /* move all the used colors inside the max limit, and |
| develop a translation table */ |
| for (i = 0, j = num_palette; i < maximum_colors; i++) |
| { |
| /* only move the colors we need to */ |
| if ((int)sort[i] >= maximum_colors) |
| { |
| png_color tmp_color; |
| |
| do |
| j--; |
| while ((int)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, sort); |
| } |
| 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). |
| [I don't understand this at all, so if someone wants to |
| work on improving it, be my guest - AED] |
| */ |
| int i; |
| int max_d; |
| int num_new_palette; |
| png_dsortpp hash; |
| png_bytep index_to_palette; |
| /* where the original index currently is in the palette */ |
| png_bytep palette_to_index; |
| /* which original index points to this palette color */ |
| |
| /* initialize palette index arrays */ |
| index_to_palette = (png_bytep)png_malloc(png_ptr, |
| (png_uint_32)(num_palette * sizeof (png_byte))); |
| palette_to_index = (png_bytep)png_malloc(png_ptr, |
| (png_uint_32)(num_palette * sizeof (png_byte))); |
| |
| /* initialize the sort array */ |
| for (i = 0; i < num_palette; i++) |
| { |
| index_to_palette[i] = (png_byte)i; |
| palette_to_index[i] = (png_byte)i; |
| } |
| |
| hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * |
| sizeof (png_dsortp))); |
| for (i = 0; i < 769; i++) |
| hash[i] = NULL; |
| /* png_memset(hash, 0, 769 * 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) |
| { |
| png_dsortp t; |
| |
| t = (png_dsortp)png_malloc(png_ptr, (png_uint_32)(sizeof |
| (png_dsort))); |
| t->next = hash[d]; |
| t->left = (png_byte)i; |
| t->right = (png_byte)j; |
| hash[d] = t; |
| } |
| } |
| } |
| |
| for (i = 0; i <= max_d; i++) |
| { |
| if (hash[i] != NULL) |
| { |
| png_dsortp p; |
| |
| for (p = hash[i]; p; p = p->next) |
| { |
| if ((int)index_to_palette[p->left] < num_new_palette && |
| (int)index_to_palette[p->right] < num_new_palette) |
| { |
| int j, next_j; |
| |
| if (num_new_palette & 1) |
| { |
| j = p->left; |
| next_j = p->right; |
| } |
| else |
| { |
| j = p->right; |
| next_j = p->left; |
| } |
| |
| num_new_palette--; |
| palette[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] == |
| index_to_palette[j]) |
| png_ptr->dither_index[k] = |
| index_to_palette[next_j]; |
| if ((int)png_ptr->dither_index[k] == |
| num_new_palette) |
| png_ptr->dither_index[k] = |
| index_to_palette[j]; |
| } |
| } |
| |
| index_to_palette[palette_to_index[num_new_palette]] = |
| index_to_palette[j]; |
| palette_to_index[index_to_palette[j]] = |
| palette_to_index[num_new_palette]; |
| |
| index_to_palette[j] = (png_byte)num_new_palette; |
| 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; |
| |
| p = hash[i]; |
| while (p) |
| { |
| png_dsortp t; |
| |
| 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, palette_to_index); |
| png_free(png_ptr, index_to_palette); |
| } |
| 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; |
| int total_bits, num_red, num_green, num_blue; |
| png_size_t num_entries; |
| png_bytep distance; |
| |
| total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + |
| PNG_DITHER_BLUE_BITS; |
| |
| num_red = (1 << PNG_DITHER_RED_BITS); |
| num_green = (1 << PNG_DITHER_GREEN_BITS); |
| num_blue = (1 << PNG_DITHER_BLUE_BITS); |
| num_entries = ((png_size_t)1 << total_bits); |
| |
| png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr, |
| (png_uint_32)(num_entries * sizeof (png_byte))); |
| |
| png_memset(png_ptr->palette_lookup, 0, num_entries * sizeof (png_byte)); |
| |
| distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * |
| sizeof(png_byte))); |
| |
| png_memset(distance, 0xff, num_entries * sizeof(png_byte)); |
| |
| for (i = 0; i < num_palette; i++) |
| { |
| int r, g, b, ir, ig, ib; |
| |
| r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); |
| g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); |
| b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); |
| |
| for (ir = 0; ir < num_red; ir++) |
| { |
| int dr, index_r; |
| |
| dr = abs(ir - r); |
| index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS)); |
| for (ig = 0; ig < num_green; ig++) |
| { |
| int dg, dt, dm, index_g; |
| |
| dg = abs(ig - g); |
| dt = dr + dg; |
| dm = ((dr > dg) ? dr : dg); |
| index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); |
| for (ib = 0; ib < num_blue; ib++) |
| { |
| int d_index, db, dmax, d; |
| |
| d_index = index_g | ib; |
| db = abs(ib - b); |
| dmax = ((dm > db) ? dm : db); |
| 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) |
| /* 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. |
| */ |
| void |
| png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) |
| { |
| png_debug(1, "in png_set_gamma\n"); |
| if (fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) |
| 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 then 8 bit depth to 8 bit depth, and expand tRNS chunks |
| * to alpha channels. |
| */ |
| void |
| png_set_expand(png_structp png_ptr) |
| { |
| png_debug(1, "in png_set_expand\n"); |
| png_ptr->transformations |= PNG_EXPAND; |
| } |
| #endif |
| |
| #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| void |
| 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; |
| } |
| #endif |
| |
| #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
| /* Convert a RGB image to a grayscale of the given width. This would |
| * allow us, for example, to convert a 24 bpp RGB image into an 8 or |
| * 16 bpp grayscale image. (Not yet implemented.) |
| */ |
| void |
| png_set_rgb_to_gray(png_structp png_ptr, int gray_bits) |
| { |
| png_debug(1, "in png_set_rgb_to_gray\n"); |
| png_ptr->transformations |= PNG_RGB_TO_GRAY; |
| /* Need to do something with gray_bits here. */ |
| png_warning(png_ptr, "RGB to GRAY transformation is not yet implemented."); |
| } |
| #endif |
| |
| #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
| void |
| 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"); |
| png_ptr->transformations |= PNG_USER_TRANSFORM; |
| png_ptr->read_user_transform_fn = read_user_transform_fn; |
| } |
| #endif |
| |
| /* Initialize everything needed for the read. This includes modifying |
| * the palette. |
| */ |
| void |
| png_init_read_transformations(png_structp png_ptr) |
| { |
| int color_type; |
| |
| png_debug(1, "in png_init_read_transformations\n"); |
| color_type = png_ptr->color_type; |
| |
| #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
| if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) |
| { |
| if (color_type == PNG_COLOR_TYPE_GRAY) |
| { |
| /* expand background chunk. */ |
| 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; |
| 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; |
| 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; |
| 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) |
| #endif |
| { |
| /* invert the alpha channel (in tRNS) unless the pixels are |
| going to be expanded, in which case leave it for later */ |
| int i; |
| for (i=0; i<(int)png_ptr->num_trans; i++) |
| png_ptr->trans[i] = 255 - png_ptr->trans[i]; |
| } |
| } |
| #endif |
| |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| png_ptr->background_1 = png_ptr->background; |
| #endif |
| #if defined(PNG_READ_GAMMA_SUPPORTED) |
| if (png_ptr->transformations & PNG_GAMMA) |
| { |
| 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) |
| { |
| int num_palette, i; |
| png_color back, back_1; |
| png_colorp palette; |
| |
| palette = png_ptr->palette; |
| num_palette = png_ptr->num_palette; |
| |
| 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_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, 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); |
| } |
| |
| 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 g, gs, m; |
| |
| m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); |
| g = 1.0; |
| 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; |
| } |
| |
| if (color_type & PNG_COLOR_MASK_COLOR) |
| { |
| /* RGB or RGBA */ |
| 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 or GRAY ALPHA */ |
| 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); |
| } |
| } |
| } |
| else |
| /* transformation does not include PNG_BACKGROUND */ |
| #endif |
| if (color_type == PNG_COLOR_TYPE_PALETTE) |
| { |
| int num_palette, i; |
| png_colorp palette; |
| |
| palette = png_ptr->palette; |
| num_palette = png_ptr->num_palette; |
| |
| 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) |
| /* No GAMMA transformation */ |
| if (png_ptr->transformations & PNG_BACKGROUND && |
| color_type == PNG_COLOR_TYPE_PALETTE) |
| { |
| int i; |
| png_color back; |
| png_colorp palette; |
| |
| 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 < (int)png_ptr->num_trans; i++) |
| { |
| if (png_ptr->trans[i] == 0) |
| { |
| palette[i] = back; |
| } |
| else if (png_ptr->trans[i] != 0xff) |
| { |
| 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 |
| |
| #if defined(PNG_READ_SHIFT_SUPPORTED) |
| if ((png_ptr->transformations & PNG_SHIFT) && |
| color_type == PNG_COLOR_TYPE_PALETTE) |
| { |
| png_uint_16 i; |
| int sr, sg, sb; |
| |
| sr = 8 - png_ptr->sig_bit.red; |
| if (sr < 0 || sr > 8) |
| sr = 0; |
| sg = 8 - png_ptr->sig_bit.green; |
| if (sg < 0 || sg > 8) |
| sg = 0; |
| sb = 8 - png_ptr->sig_bit.blue; |
| if (sb < 0 || sb > 8) |
| sb = 0; |
| for (i = 0; i < png_ptr->num_palette; i++) |
| { |
| png_ptr->palette[i].red >>= sr; |
| png_ptr->palette[i].green >>= sg; |
| png_ptr->palette[i].blue >>= sb; |
| } |
| } |
| #endif |
| } |
| |
| /* Modify the info structure to reflect the transformations. The |
| * info should be updated so a PNG file could be written with it, |
| * assuming the transformations result in valid PNG data. |
| */ |
| void |
| png_read_transform_info(png_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) |
| 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) |
| info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
| if (info_ptr->bit_depth < 8) |
| info_ptr->bit_depth = 8; |
| info_ptr->num_trans = 0; |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| if (png_ptr->transformations & PNG_BACKGROUND) |
| { |
| info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
| info_ptr->num_trans = 0; |
| info_ptr->background = png_ptr->background; |
| } |
| #endif |
| |
| #if defined(PNG_READ_16_TO_8_SUPPORTED) |
| if ((png_ptr->transformations & PNG_16_TO_8) && info_ptr->bit_depth == 16) |
| info_ptr->bit_depth = 8; |
| #endif |
| |
| #if defined(PNG_READ_DITHER_SUPPORTED) |
| if (png_ptr->transformations & PNG_DITHER) |
| { |
| if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
| (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && |
| png_ptr->palette_lookup && info_ptr->bit_depth == 8) |
| { |
| info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_PACK_SUPPORTED) |
| if ((png_ptr->transformations & PNG_PACK) && info_ptr->bit_depth < 8) |
| info_ptr->bit_depth = 8; |
| #endif |
| |
| #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
| !(info_ptr->color_type & PNG_COLOR_MASK_COLOR)) |
| info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
| #endif |
| |
| if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| info_ptr->channels = 1; |
| else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) |
| info_ptr->channels = 3; |
| else |
| info_ptr->channels = 1; |
| |
| #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
| if ((png_ptr->transformations & PNG_STRIP_ALPHA) && |
| info_ptr->color_type & PNG_COLOR_MASK_ALPHA) |
| { |
| info_ptr->channels--; |
| info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
| } |
| #endif |
| |
| #if defined(PNG_READ_FILLER_SUPPORTED) |
| if ((png_ptr->transformations & PNG_FILLER) && |
| info_ptr->color_type & PNG_COLOR_TYPE_RGB && |
| info_ptr->channels == 3) |
| { |
| info_ptr->channels = 4; |
| } |
| #endif |
| |
| if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) |
| info_ptr->channels++; |
| info_ptr->pixel_depth = (png_byte)(info_ptr->channels * |
| info_ptr->bit_depth); |
| |
| info_ptr->rowbytes = ((info_ptr->width * info_ptr->pixel_depth + 7) >> 3); |
| } |
| |
| /* Transform the row. The order of transformations is significant, |
| * and is very touchy. If you add a transformation, take care to |
| * decide how it fits in with the other transformations here. |
| */ |
| void |
| png_do_read_transformations(png_structp png_ptr) |
| { |
| png_debug(1, "in png_do_read_transformations\n"); |
| #if !defined(PNG_USELESS_TESTS_SUPPORTED) |
| if (png_ptr->row_buf == NULL) |
| { |
| #if !defined(PNG_NO_STDIO) |
| char msg[50]; |
| |
| sprintf(msg, "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 |
| } |
| #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->transformations & PNG_EXPAND) |
| { |
| if (png_ptr->num_trans) |
| png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| &(png_ptr->trans_values)); |
| else |
| png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| NULL); |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
| if (png_ptr->transformations & PNG_STRIP_ALPHA) |
| png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| PNG_FLAG_FILLER_AFTER); |
| #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), |
| &(png_ptr->background_1), |
| png_ptr->gamma_table, png_ptr->gamma_from_1, |
| png_ptr->gamma_to_1, png_ptr->gamma_16_table, |
| png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, |
| png_ptr->gamma_shift); |
| #endif |
| |
| #if defined(PNG_READ_GAMMA_SUPPORTED) |
| if ((png_ptr->transformations & PNG_GAMMA) && |
| !(png_ptr->transformations & PNG_BACKGROUND) && |
| (png_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_RGB_TO_GRAY_SUPPORTED) |
| if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
| png_do_rgb_to_gray(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #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 (png_ptr->transformations & PNG_GRAY_TO_RGB) |
| png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| #endif |
| |
| #if defined(PNG_READ_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 */ |
| #endif |
| |
| } |
| |
| #if defined(PNG_READ_PACK_SUPPORTED) |
| /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
| * without changing the actual values. Thus, if you had a row with |
| * a bit depth of 1, you would end up with bytes that only contained |
| * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
| * png_do_shift() after this. |
| */ |
| void |
| png_do_unpack(png_row_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 shift, i; |
| png_bytep sp, dp; |
| |
| switch (row_info->bit_depth) |
| { |
| case 1: |
| { |
| sp = row + (png_size_t)((row_info->width - 1) >> 3); |
| dp = row + (png_size_t)row_info->width - 1; |
| shift = 7 - (int)((row_info->width + 7) & 7); |
| for (i = 0; i < row_info->width; i++) |
| { |
| *dp = (png_byte)((*sp >> shift) & 0x1); |
| if (shift == 7) |
| { |
| shift = 0; |
| sp--; |
| } |
| else |
| shift++; |
| |
| dp--; |
| } |
| break; |
| } |
| case 2: |
| { |
| |
| sp = row + (png_size_t)((row_info->width - 1) >> 2); |
| dp = row + (png_size_t)row_info->width - 1; |
| shift = (int)((3 - ((row_info->width + 3) & 3)) << 1); |
| for (i = 0; i < row_info->width; i++) |
| { |
| *dp = (png_byte)((*sp >> shift) & 0x3); |
| if (shift == 6) |
| { |
| shift = 0; |
| sp--; |
| } |
| else |
| shift += 2; |
| |
| dp--; |
| } |
| break; |
| } |
| case 4: |
| { |
| sp = row + (png_size_t)((row_info->width - 1) >> 1); |
| dp = row + (png_size_t)row_info->width - 1; |
| shift = (int)((1 - ((row_info->width + 1) & 1)) << 2); |
| for (i = 0; i < row_info->width; i++) |
| { |
| *dp = (png_byte)((*sp >> shift) & 0xf); |
| 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_info->width * row_info->channels; |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_SHIFT_SUPPORTED) |
| /* Reverse the effects of png_do_shift. This routine merely shifts the |
| * pixels back to their significant bits values. Thus, if you have |
| * a row of bit depth 8, but only 5 are significant, this will shift |
| * the values back to 0 through 31. |
| */ |
| void |
| png_do_unshift(png_row_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, c; |
| png_uint_16 value; |
| |
| channels = 0; |
| if (row_info->color_type & PNG_COLOR_MASK_COLOR) |
| { |
| shift[channels++] = row_info->bit_depth - sig_bits->red; |
| shift[channels++] = row_info->bit_depth - sig_bits->green; |
| shift[channels++] = row_info->bit_depth - sig_bits->blue; |
| } |
| else |
| { |
| shift[channels++] = row_info->bit_depth - sig_bits->gray; |
| } |
| if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
| { |
| shift[channels++] = row_info->bit_depth - sig_bits->alpha; |
| } |
| |
| value = 0; |
| |
| 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; |
| |
| for (bp = row, i = 0; i < row_info->rowbytes; i++, bp++) |
| { |
| *bp >>= 1; |
| *bp &= 0x55; |
| } |
| break; |
| } |
| case 4: |
| { |
| png_bytep bp; |
| png_byte mask; |
| png_uint_32 i; |
| |
| mask = (png_byte)(((int)0xf0 >> shift[0]) & (int)0xf0) | |
| (png_byte)((int)0xf >> shift[0]); |
| for (bp = row, i = 0; i < row_info->rowbytes; i++, bp++) |
| { |
| *bp >>= shift[0]; |
| *bp &= mask; |
| } |
| break; |
| } |
| case 8: |
| { |
| png_bytep bp; |
| png_uint_32 i; |
| |
| for (bp = row, i = 0; i < row_info->width; i++) |
| { |
| for (c = 0; c < (int)row_info->channels; c++, bp++) |
| { |
| *bp >>= shift[c]; |
| } |
| } |
| break; |
| } |
| case 16: |
| { |
| png_bytep bp; |
| png_size_t i; |
| |
| for (bp = row, i = 0; i < row_info->width; i++) |
| { |
| for (c = 0; c < (int)row_info->channels; c++, bp += 2) |
| { |
| value = (png_uint_16)((*bp << 8) + *(bp + 1)); |
| value >>= shift[c]; |
| *bp = (png_byte)(value >> 8); |
| *(bp + 1) = (png_byte)(value & 0xff); |
| } |
| } |
| break; |
| } |
| } |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_16_TO_8_SUPPORTED) |
| /* chop rows of bit depth 16 down to 8 */ |
| void |
| png_do_chop(png_row_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, dp; |
| png_uint_32 i; |
| |
| sp = row; |
| dp = row; |
| for (i = 0; i < row_info->width * row_info->channels; 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 |
| *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 |
| 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 |
| { |
| 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, dp; |
| png_byte save; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->width; i++) |
| { |
| save = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = save; |
| } |
| } |
| /* This converts from RRGGBBAA to AARRGGBB */ |
| else |
| { |
| png_bytep sp, dp; |
| png_byte save[2]; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->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, dp; |
| png_byte save; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->width; i++) |
| { |
| save = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = save; |
| } |
| } |
| /* This converts from GGAA to AAGG */ |
| else |
| { |
| png_bytep sp, dp; |
| png_byte save[2]; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->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 |
| 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 |
| { |
| 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, dp; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->width; i++) |
| { |
| *(--dp) = 255 - *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| } |
| } |
| /* This inverts the alpha channel in RRGGBBAA */ |
| else |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->width; i++) |
| { |
| *(--dp) = 255 - *(--sp); |
| *(--dp) = 255 - *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--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, dp; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->width; i++) |
| { |
| *(--dp) = 255 - *(--sp); |
| *(--dp) = *(--sp); |
| } |
| } |
| /* This inverts the alpha channel in GGAA */ |
| else |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| for (i = 0, sp = dp = row + row_info->rowbytes; |
| i < row_info->width; i++) |
| { |
| *(--dp) = 255 - *(--sp); |
| *(--dp) = 255 - *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| } |
| } |
| } |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_FILLER_SUPPORTED) |
| /* Add filler channel if we have RGB color */ |
| void |
| png_do_read_filler(png_row_infop row_info, png_bytep row, |
| png_uint_32 filler, png_uint_32 flags) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| 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_RGB && row_info->bit_depth == 8) |
| { |
| /* This changes the data from RGB to RGBX */ |
| if (flags & PNG_FLAG_FILLER_AFTER) |
| { |
| for (i = 1, sp = row + (png_size_t)row_info->width * 3, |
| dp = row + (png_size_t)row_info->width * 4; |
| i < row_info->width; |
| i++) |
| { |
| *(--dp) = (png_byte)filler; |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| } |
| *(--dp) = (png_byte)filler; |
| row_info->channels = 4; |
| row_info->pixel_depth = 32; |
| row_info->rowbytes = row_info->width * 4; |
| } |
| /* This changes the data from RGB to XRGB */ |
| else |
| { |
| for (i = 0, sp = row + (png_size_t)row_info->width * 3, |
| dp = row + (png_size_t)row_info->width * 4; |
| i < row_info->width; |
| i++) |
| { |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = *(--sp); |
| *(--dp) = (png_byte)filler; |
| } |
| row_info->channels = 4; |
| row_info->pixel_depth = 32; |
| row_info->rowbytes = row_info->width * 4; |
| } |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| /* expand grayscale files to RGB, with or without alpha */ |
| void |
| png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| |
| 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) |
| { |
| for (i = 0, sp = row + (png_size_t)row_info->width - 1, |
| dp = row + (png_size_t)row_info->width * 3 - 1; |
| i < row_info->width; |
| i++) |
| { |
| *(dp--) = *sp; |
| *(dp--) = *sp; |
| *(dp--) = *sp; |
| sp--; |
| } |
| } |
| else |
| { |
| for (i = 0, sp = row + (png_size_t)row_info->width * 2 - 1, |
| dp = row + (png_size_t)row_info->width * 6 - 1; |
| i < row_info->width; |
| i++) |
| { |
| *(dp--) = *sp; |
| *(dp--) = *(sp - 1); |
| *(dp--) = *sp; |
| *(dp--) = *(sp - 1); |
| *(dp--) = *sp; |
| *(dp--) = *(sp - 1); |
| sp--; |
| sp--; |
| } |
| } |
| } |
| else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| { |
| if (row_info->bit_depth == 8) |
| { |
| for (i = 0, sp = row + (png_size_t)row_info->width * 2 - 1, |
| dp = row + (png_size_t)row_info->width * 4 - 1; |
| i < row_info->width; |
| i++) |
| { |
| *(dp--) = *(sp--); |
| *(dp--) = *sp; |
| *(dp--) = *sp; |
| *(dp--) = *sp; |
| sp--; |
| } |
| } |
| else |
| { |
| for (i = 0, sp = row + (png_size_t)row_info->width * 4 - 1, |
| dp = row + (png_size_t)row_info->width * 8 - 1; |
| i < row_info->width; |
| i++) |
| { |
| *(dp--) = *(sp--); |
| *(dp--) = *(sp--); |
| *(dp--) = *sp; |
| *(dp--) = *(sp - 1); |
| *(dp--) = *sp; |
| *(dp--) = *(sp - 1); |
| *(dp--) = *sp; |
| *(dp--) = *(sp - 1); |
| sp--; |
| sp--; |
| } |
| } |
| } |
| row_info->channels += (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 = ((row_info->width * |
| row_info->pixel_depth + 7) >> 3); |
| } |
| } |
| #endif |
| |
| /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth |
| * large of png_color. This lets grayscale images be treated as |
| * paletted. Most useful for gamma correction and simplification |
| * of code. |
| */ |
| void |
| png_build_grayscale_palette(int bit_depth, png_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 |
| 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) |
| if ((png_ptr->transformations & (PNG_GAMMA)) && |
| (png_ptr->transformations & (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 |
| png_do_background(png_row_infop row_info, png_bytep row, |
| png_color_16p trans_values, png_color_16p background, |
| 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) |
| { |
| png_bytep sp, dp; |
| png_uint_32 i; |
| 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_info->width; i++) |
| { |
| if ((png_uint_16)((*sp >> shift) & 0x1) |
| == 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: |
| { |
| sp = row; |
| shift = 6; |
| for (i = 0; i < row_info->width; i++) |
| { |
| if ((png_uint_16)((*sp >> shift) & 0x3) |
| == 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: |
| { |
| sp = row; |
| shift = 4; |
| for (i = 0; i < row_info->width; i++) |
| { |
| if ((png_uint_16)((*sp >> shift) & 0xf) |
| == 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) |
| { |
| for (i = 0, sp = row; i < row_info->width; i++, sp++) |
| { |
| if (*sp == trans_values->gray) |
| { |
| *sp = (png_byte)background->gray; |
| } |
| else |
| { |
| *sp = gamma_table[*sp]; |
| } |
| } |
| } |
| else |
| #endif |
| { |
| for (i = 0, sp = row; i < row_info->width; i++, sp++) |
| { |
| if (*sp == trans_values->gray) |
| { |
| *sp = (png_byte)background->gray; |
| } |
| } |
| } |
| break; |
| } |
| case 16: |
| { |
| #if defined(PNG_READ_GAMMA_SUPPORTED) |
| if (gamma_16 != NULL) |
| { |
| for (i = 0, sp = row; i < row_info->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 |
| { |
| for (i = 0, sp = row; i < row_info->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) |
| { |
| for (i = 0, sp = row; i < row_info->width; i++, sp += 3) |
| { |
| if (*sp == trans_values->red && |
| *(sp + 1) == trans_values->green && |
| *(sp + 2) == trans_values->blue) |
| { |
| *sp = (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 |
| { |
| for (i = 0, sp = row; i < row_info->width; i++, sp += 3) |
| { |
| if (*sp == trans_values->red && |
| *(sp + 1) == trans_values->green && |
| *(sp + 2) == trans_values->blue) |
| { |
| *sp = (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) |
| { |
| for (i = 0, sp = row; i < row_info->width; i++, sp += 6) |
| { |
| png_uint_16 r, g, b; |
| |
| r = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| 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; |
| 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 |
| { |
| for (i = 0, sp = row; i < row_info->width; i++, sp += 6) |
| { |
| png_uint_16 r, g, b; |
| |
| r = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| 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) |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 2, dp++) |
| { |
| png_uint_16 a; |
| |
| a = *(sp + 1); |
| if (a == 0xff) |
| { |
| *dp = gamma_table[*sp]; |
| } |
| else if (a == 0) |
| { |
| /* 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 |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 2, dp++) |
| { |
| png_byte a; |
| |
| a = *(sp + 1); |
| if (a == 0xff) |
| { |
| *dp = *sp; |
| } |
| else if (a == 0) |
| { |
| *dp = (png_byte)background->gray; |
| } |
| else |
| { |
| png_composite(*dp, *sp, a, background_1->gray); |
| } |
| } |
| } |
| } |
| 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) |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 4, dp += 2) |
| { |
| png_uint_16 a; |
| |
| a = ((png_uint_16)(*(sp + 2)) << 8) + *(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); |
| } |
| else if (a == 0) |
| { |
| /* background is already in screen gamma */ |
| *dp = (png_byte)((background->gray >> 8) & 0xff); |
| *(dp + 1) = (png_byte)(background->gray & 0xff); |
| } |
| 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); |
| } |
| } |
| } |
| else |
| #endif |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 4, dp += 2) |
| { |
| png_uint_16 a; |
| |
| a = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| if (a == (png_uint_16)0xffff) |
| { |
| png_memcpy(dp, sp, 2); |
| } |
| else if (a == 0) |
| { |
| *dp = (png_byte)((background->gray >> 8) & 0xff); |
| *(dp + 1) = (png_byte)(background->gray & 0xff); |
| } |
| 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); |
| } |
| } |
| } |
| } |
| 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) |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 4, dp += 3) |
| { |
| png_byte a; |
| |
| a = *(sp + 3); |
| if (a == 0xff) |
| { |
| *dp = gamma_table[*sp]; |
| *(dp + 1) = gamma_table[*(sp + 1)]; |
| *(dp + 2) = gamma_table[*(sp + 2)]; |
| } |
| else if (a == 0) |
| { |
| /* 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 |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 4, dp += 3) |
| { |
| png_byte a; |
| |
| 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) |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 8, dp += 6) |
| { |
| png_uint_16 a; |
| |
| 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->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->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->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 |
| { |
| for (i = 0, sp = row, dp = row; |
| i < row_info->width; i++, sp += 8, dp += 6) |
| { |
| png_uint_16 a; |
| |
| 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 r, g, b, v; |
| |
| r = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| 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 = ((row_info->width * |
| row_info->pixel_depth + 7) >> 3); |
| } |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_GAMMA_SUPPORTED) |
| /* Gamma correct the image, avoiding the alpha channel. Make sure |
| * you do this after you deal with the trasparency issue on grayscale |
| * or rgb images. If your bit depth is 8, use gamma_table, if it |
| * is 16, use gamma_16_table and gamma_shift. Build these with |
| * build_gamma_table(). |
| */ |
| void |
| 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_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) |
| { |
| for (i = 0, sp = row; i < row_info->width; i++) |
| { |
| *sp = gamma_table[*sp]; |
| sp++; |
| *sp = gamma_table[*sp]; |
| sp++; |
| *sp = gamma_table[*sp]; |
| sp++; |
| } |
| } |
| else /* if (row_info->bit_depth == 16) */ |
| { |
| for (i = 0, sp = row; i < row_info->width; i++) |
| { |
| png_uint_16 v; |
| |
| v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| *sp = (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) |
| { |
| for (i = 0, sp = row; |
| i < row_info->width; i++) |
| { |
| *sp = gamma_table[*sp]; |
| sp++; |
| *sp = gamma_table[*sp]; |
| sp++; |
| *sp = gamma_table[*sp]; |
| sp++; |
| sp++; |
| } |
| } |
| else /* if (row_info->bit_depth == 16) */ |
| { |
| for (i = 0, sp = row; |
| i < row_info->width; i++) |
| { |
| png_uint_16 v; |
| |
| v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| *sp = (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) |
| { |
| for (i = 0, sp = row; |
| i < row_info->width; i++) |
| { |
| *sp = gamma_table[*sp]; |
| sp += 2; |
| } |
| } |
| else /* if (row_info->bit_depth == 16) */ |
| { |
| for (i = 0, sp = row; |
| i < row_info->width; i++) |
| { |
| png_uint_16 v; |
| |
| v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| *sp = (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) |
| { |
| for (i = 0, sp = row; i < row_info->width; i += 4) |
| { |
| int a = *sp & 0xc0; |
| int b = *sp & 0x30; |
| int c = *sp & 0x0c; |
| int d = *sp & 0x03; |
| |
| *sp = ((((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) |
| { |
| for (i = 0, sp = row; i < row_info->width; i += 2) |
| { |
| int msb = *sp & 0xf0; |
| int lsb = *sp & 0x0f; |
| |
| *sp = (((int)gamma_table[msb | (msb >> 4)]) & 0xf0) | |
| (((int)gamma_table[(lsb << 4) | lsb]) >> 4); |
| sp++; |
| } |
| } |
| else if (row_info->bit_depth == 8) |
| { |
| for (i = 0, sp = row; i < row_info->width; i++) |
| { |
| *sp = gamma_table[*sp]; |
| sp++; |
| } |
| } |
| else if (row_info->bit_depth == 16) |
| { |
| for (i = 0, sp = row; i < row_info->width; i++) |
| { |
| png_uint_16 v; |
| |
| v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| *sp = (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 |
| 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_debug(1, "in png_do_expand_palette\n"); |
| if ( |
| #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|