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- /* pngrtran.c - transforms the data in a row for PNG readers
- *
- * libpng 0.99b
- * 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
- * February 3, 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 (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
- /* 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];
- }
- }
- }
- else
- /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN)*/
- {
- 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)
- {
- png_ptr->background_1.red = (png_uint_16)(pow(
- (double)png_ptr->background.red / m, g) * m + .5);
- png_ptr->background_1.green = (png_uint_16)(pow(
- (double)png_ptr->background.green / m, g) * m + .5);
- png_ptr->background_1.blue = (png_uint_16)(pow(
- (double)png_ptr->background.blue / m, g) * m + .5);
- png_ptr->background.red = (png_uint_16)(pow(
- (double)png_ptr->background.red / m, gs) * m + .5);
- png_ptr->background.green = (png_uint_16)(pow(
- (double)png_ptr->background.green / m, gs) * m + .5);
- png_ptr->background.blue = (png_uint_16)(pow(
- (double)png_ptr->background.blue / m, gs) * m + .5);
- }
- else
- {
- png_ptr->background_1.gray = (png_uint_16)(pow(
- (double)png_ptr->background.gray / m, g) * m + .5);
- png_ptr->background.gray = (png_uint_16)(pow(
- (double)png_ptr->background.gray / m, gs) * m + .5);
- }
- }
- }
- else
- #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)
- 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 =
- (png_size_t)((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_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_size_t)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_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_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_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_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 = (png_size_t)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_size_t 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_size_t 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_size_t 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 = (png_size_t)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) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = 255 - *(--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) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = 255 - *(--sp);
- *(--dp) = 255 - *(--sp);
- }
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- /* This inverts the alpha channel in AG */
- 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) = *(--sp);
- *(--dp) = 255 - *(--sp);
- }
- }
- /* This inverts the alpha channel in AAGG */
- else
- {
- png_bytep sp, dp;
- png_uint_32 i;
- for (i = 0, sp = dp = row + row_info->rowbytes;
- i < row_info->width; i++)
- {
- *(--dp) = *(--sp);
- *(--dp) = *(--sp);
- *(--dp) = 255 - *(--sp);
- *(--dp) = 255 - *(--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 = (png_size_t)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 = (png_size_t)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 = (png_size_t)((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)
- {
- int i;
- 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 < num_palette; i++)
- {
- if (i >= (int)png_ptr->num_trans ||
- png_ptr->trans[i] == 0)
- {
- palette[i].red = back.red;
- palette[i].green = back.green;
- palette[i].blue = back.blue;
- }
- else if (i < (int)png_ptr->num_trans ||
- 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:
- {
- /* We currently don't do gamma correction for 2 and 4 bit */
- 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 = (png_size_t)((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)
- row != NULL && row_info != NULL &&
- #endif
- row_info->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- if (row_info->bit_depth < 8)
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- sp = row + (png_size_t)((row_info->width - 1) >> 3);
- dp = row + (png_size_t)row_info->width - 1;
- shift = 7 - (int)((row_info->width + 7) & 7);
- for (i = 0; i < row_info->width; i++)
- {
- if ((*sp >> shift) & 0x1)
- *dp = 1;
- else
- *dp = 0;
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
- else
- shift++;
- dp--;
- }
- break;
- }
- case 2:
- {
- sp = row + (png_size_t)((row_info->width - 1) >> 2);
- dp = row + (png_size_t)row_info->width - 1;
- shift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
- for (i = 0; i < row_info->width; i++)
- {
- value = (*sp >> shift) & 0x3;
- *dp = (png_byte)value;
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
- else
- shift += 2;
- dp--;
- }
- break;
- }
- case 4:
- {
- sp = row + (png_size_t)((row_info->width - 1) >> 1);
- dp = row + (png_size_t)row_info->width - 1;
- shift = (int)((row_info->width & 1) << 2);
- for (i = 0; i < row_info->width; i++)
- {
- value = (*sp >> shift) & 0xf;
- *dp = (png_byte)value;
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
- else
- shift += 4;
- dp--;
- }
- break;
- }
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 8;
- row_info->rowbytes = (png_size_t)row_info->width;
- }
- switch (row_info->bit_depth)
- {
- case 8:
- {
- if (trans != NULL)
- {
- sp = row + (png_size_t)row_info->width - 1;
- dp = row + (png_size_t)(row_info->width << 2) - 1;
- for (i = 0; i < row_info->width; i++)
- {
- if ((int)(*sp) >= num_trans)
- *dp-- = 0xff;
- else
- *dp-- = trans[*sp];
- *dp-- = palette[*sp].blue;
- *dp-- = palette[*sp].green;
- *dp-- = palette[*sp].red;
- sp--;
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 32;
- row_info->rowbytes = (png_size_t)row_info->width * 4;
- row_info->color_type = 6;
- row_info->channels = 4;
- }
- else
- {
- sp = row + (png_size_t)row_info->width - 1;
- dp = row + (png_size_t)(row_info->width * 3) - 1;
- for (i = 0; i < row_info->width; i++)
- {
- *dp-- = palette[*sp].blue;
- *dp-- = palette[*sp].green;
- *dp-- = palette[*sp].red;
- sp--;
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 24;
- row_info->rowbytes = (png_size_t)row_info->width * 3;
- row_info->color_type = 2;
- row_info->channels = 3;
- }
- break;
- }
- }
- }
- }
- /* If the bit depth < 8, it is expanded to 8. Also, if the
- * transparency value is supplied, an alpha channel is built.
- */
- void
- png_do_expand(png_row_infop row_info, png_bytep row,
- png_color_16p trans_value)
- {
- int shift, value;
- png_bytep sp, dp;
- png_uint_32 i;
- png_debug(1, "in png_do_expand\n");
- #if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
- #endif
- {
- if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
- {
- png_uint_16 gray = trans_value ? trans_value->gray : 0;
- if (row_info->bit_depth < 8)
- {
- switch (row_info->bit_depth)
- {
- case 1:
- {
- gray *= 0xff;
- sp = row + (png_size_t)((row_info->width - 1) >> 3);
- dp = row + (png_size_t)row_info->width - 1;
- shift = 7 - (int)((row_info->width + 7) & 7);
- for (i = 0; i < row_info->width; i++)
- {
- if ((*sp >> shift) & 0x1)
- *dp = 0xff;
- else
- *dp = 0;
- if (shift == 7)
- {
- shift = 0;
- sp--;
- }
- else
- shift++;
- dp--;
- }
- break;
- }
- case 2:
- {
- gray *= 0x55;
- sp = row + (png_size_t)((row_info->width - 1) >> 2);
- dp = row + (png_size_t)row_info->width - 1;
- shift = (int)((3 - ((row_info->width + 3) & 3)) << 1);
- for (i = 0; i < row_info->width; i++)
- {
- value = (*sp >> shift) & 0x3;
- *dp = (png_byte)(value | (value << 2) | (value << 4) |
- (value << 6));
- if (shift == 6)
- {
- shift = 0;
- sp--;
- }
- else
- shift += 2;
- dp--;
- }
- break;
- }
- case 4:
- {
- gray *= 0x11;
- sp = row + (png_size_t)((row_info->width - 1) >> 1);
- dp = row + (png_size_t)row_info->width - 1;
- shift = (int)((1 - ((row_info->width + 1) & 1)) << 2);
- for (i = 0; i < row_info->width; i++)
- {
- value = (*sp >> shift) & 0xf;
- *dp = (png_byte)(value | (value << 4));
- if (shift == 4)
- {
- shift = 0;
- sp--;
- }
- else
- shift = 4;
- dp--;
- }
- break;
- }
- }
- row_info->bit_depth = 8;
- row_info->pixel_depth = 8;
- row_info->rowbytes = (png_size_t)row_info->width;
- }
- if (trans_value != NULL)
- {
- if (row_info->bit_depth == 8)
- {
- sp = row + (png_size_t)row_info->width - 1;
- dp = row + (png_size_t)(row_info->width << 1) - 1;
- for (i = 0; i < row_info->width; i++)
- {
- if (*sp == gray)
- *dp-- = 0;
- else
- *dp-- = 0xff;
- *dp-- = *sp--;
- }
- }
- else if (row_info->bit_depth == 16)
- {
- sp = row + row_info->rowbytes - 1;
- dp = row + (row_info->rowbytes << 1) - 1;
- for (i = 0; i < row_info->width; i++)
- {
- if (((png_uint_16)*(sp) |
- ((png_uint_16)*(sp - 1) << 8)) == gray)
- {
- *dp-- = 0;
- *dp-- = 0;
- }
- else
- {
- *dp-- = 0xff;
- *dp-- = 0xff;
- }
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
- row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
- row_info->channels = 2;
- row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
- row_info->rowbytes =
- (png_size_t)((row_info->width * row_info->pixel_depth) >> 3);
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
- {
- if (row_info->bit_depth == 8)
- {
- sp = row + (png_size_t)row_info->rowbytes - 1;
- dp = row + (png_size_t)(row_info->width << 2) - 1;
- for (i = 0; i < row_info->width; i++)
- {
- if (*(sp - 2) == trans_value->red &&
- *(sp - 1) == trans_value->green &&
- *(sp - 0) == trans_value->blue)
- *dp-- = 0;
- else
- *dp-- = 0xff;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
- else if (row_info->bit_depth == 16)
- {
- sp = row + row_info->rowbytes - 1;
- dp = row + (png_size_t)(row_info->width << 3) - 1;
- for (i = 0; i < row_info->width; i++)
- {
- if ((((png_uint_16)*(sp - 4) |
- ((png_uint_16)*(sp - 5) << 8)) == trans_value->red) &&
- (((png_uint_16)*(sp - 2) |
- ((png_uint_16)*(sp - 3) << 8)) == trans_value->green) &&
- (((png_uint_16)*(sp - 0) |
- ((png_uint_16)*(sp - 1) << 8)) == trans_value->blue))
- {
- *dp-- = 0;
- *dp-- = 0;
- }
- else
- {
- *dp-- = 0xff;
- *dp-- = 0xff;
- }
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- *dp-- = *sp--;
- }
- }
- row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
- row_info->channels = 4;
- row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
- row_info->rowbytes =
- (png_size_t)((row_info->width * row_info->pixel_depth) >> 3);
- }
- }
- }
- #endif
- #if defined(PNG_READ_DITHER_SUPPORTED)
- void
- png_do_dither(png_row_infop row_info, png_bytep row,
- png_bytep palette_lookup, png_bytep dither_lookup)
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_debug(1, "in png_do_dither\n");
- #if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
- #endif
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
- palette_lookup && row_info->bit_depth == 8)
- {
- png_uint_32 rowbytes;
- int r, g, b, p;
- sp = row;
- dp = row;
- for (i = 0; i < row_info->width; i++)
- {
- r = *sp++;
- g = *sp++;
- b = *sp++;
- /* this looks real messy, but the compiler will reduce
- it down to a reasonable formula. For example, with
- 5 bits per color, we get:
- p = (((r >> 3) & 0x1f) << 10) |
- (((g >> 3) & 0x1f) << 5) |
- ((b >> 3) & 0x1f);
- */
- p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
- ((1 << PNG_DITHER_RED_BITS) - 1)) <<
- (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
- (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
- ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
- (PNG_DITHER_BLUE_BITS)) |
- ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
- ((1 << PNG_DITHER_BLUE_BITS) - 1));
- *dp++ = palette_lookup[p];
- }
- row_info->color_type = PNG_COLOR_TYPE_PALETTE;
- row_info->channels = 1;
- row_info->pixel_depth = row_info->bit_depth;
- rowbytes = ((row_info->width * row_info->pixel_depth + 7) >> 3);
- row_info->rowbytes = (png_size_t)rowbytes;
- if((png_uint_32)row_info->rowbytes != rowbytes)
- /* we should call png_error here, but we don't have png_ptr */
- row_info->rowbytes = (png_size_t)0;
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
- palette_lookup != NULL && row_info->bit_depth == 8)
- {
- png_uint_32 rowbytes;
- int r, g, b, p;
- sp = row;
- dp = row;
- for (i = 0; i < row_info->width; i++)
- {
- r = *sp++;
- g = *sp++;
- b = *sp++;
- sp++;
- p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
- ((1 << PNG_DITHER_RED_BITS) - 1)) <<
- (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
- (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
- ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
- (PNG_DITHER_BLUE_BITS)) |
- ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
- ((1 << PNG_DITHER_BLUE_BITS) - 1));
- *dp++ = palette_lookup[p];
- }
- row_info->color_type = PNG_COLOR_TYPE_PALETTE;
- row_info->channels = 1;
- row_info->pixel_depth = row_info->bit_depth;
- rowbytes = ((row_info->width * row_info->pixel_depth + 7) >> 3);
- row_info->rowbytes = (png_size_t)rowbytes;
- if((png_uint_32)row_info->rowbytes != rowbytes)
- /* we should call png_error here, but we don't have png_ptr */
- row_info->rowbytes = (png_size_t)0;
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
- dither_lookup && row_info->bit_depth == 8)
- {
- sp = row;
- for (i = 0; i < row_info->width; i++, sp++)
- {
- *sp = dither_lookup[*sp];
- }
- }
- }
- }
- #endif
- #if defined(PNG_READ_GAMMA_SUPPORTED)
- static int png_gamma_shift[] =
- {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0};
- /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
- * tables, we don't make a full table if we are reducing to 8-bit in
- * the future. Note also how the gamma_16 tables are segmented so that
- * we don't need to allocate > 64K chunks for a full 16-bit table.
- */
- void
- png_build_gamma_table(png_structp png_ptr)
- {
- png_debug(1, "in png_build_gamma_table\n");
- if (png_ptr->bit_depth <= 8)
- {
- int i;
- double g;
- g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
- png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)256);
- for (i = 0; i < 256; i++)
- {
- png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,
- g) * 255.0 + .5);
- }
- #if defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->transformations & PNG_BACKGROUND)
- {
- g = 1.0 / (png_ptr->gamma);
- png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)256);
- for (i = 0; i < 256; i++)
- {
- png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,
- g) * 255.0 + .5);
- }
- g = 1.0 / (png_ptr->screen_gamma);
- png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
- (png_uint_32)256);
- for (i = 0; i < 256; i++)
- {
- png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
- g) * 255.0 + .5);
- }
- }
- #endif /* PNG_BACKGROUND_SUPPORTED */
- }
- else
- {
- double g;
- int i, j, shift, num;
- int sig_bit;
- png_uint_32 ig;
- if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
- {
- sig_bit = (int)png_ptr->sig_bit.red;
- if ((int)png_ptr->sig_bit.green > sig_bit)
- sig_bit = png_ptr->sig_bit.green;
- if ((int)png_ptr->sig_bit.blue > sig_bit)
- sig_bit = png_ptr->sig_bit.blue;
- }
- else
- {
- sig_bit = (int)png_ptr->sig_bit.gray;
- }
- if (sig_bit > 0)
- shift = 16 - sig_bit;
- else
- shift = 0;
- if (png_ptr->transformations & PNG_16_TO_8)
- {
- if (shift < (16 - PNG_MAX_GAMMA_8))
- shift = (16 - PNG_MAX_GAMMA_8);
- }
- if (shift > 8)
- shift = 8;
- if (shift < 0)
- shift = 0;
- png_ptr->gamma_shift = (png_byte)shift;
- num = (1 << (8 - shift));
- g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
- png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
- (png_uint_32)(num * sizeof (png_uint_16p)));
- if ((png_ptr->transformations & PNG_16_TO_8) &&
- !(png_ptr->transformations & PNG_BACKGROUND))
- {
- double fin, fout;
- png_uint_32 last, max;
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * sizeof (png_uint_16)));
- }
- g = 1.0 / g;
- last = 0;
- for (i = 0; i < 256; i++)
- {
- fout = ((double)i + 0.5) / 256.0;
- fin = pow(fout, g);
- max = (png_uint_32)(fin * (double)((png_uint_32)num << 8));
- while (last <= max)
- {
- png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
- [(int)(last >> (8 - shift))] = (png_uint_16)(
- (png_uint_16)i | ((png_uint_16)i << 8));
- last++;
- }
- }
- while (last < ((png_uint_32)num << 8))
- {
- png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
- [(int)(last >> (8 - shift))] = (png_uint_16)65535L;
- last++;
- }
- }
- else
- {
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * sizeof (png_uint_16)));
- ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
- for (j = 0; j < 256; j++)
- {
- png_ptr->gamma_16_table[i][j] =
- (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
- 65535.0, g) * 65535.0 + .5);
- }
- }
- }
- #if defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->transformations & PNG_BACKGROUND)
- {
- g = 1.0 / (png_ptr->gamma);
- png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
- (png_uint_32)(num * sizeof (png_uint_16p )));
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * sizeof (png_uint_16)));
- ig = (((png_uint_32)i *
- (png_uint_32)png_gamma_shift[shift]) >> 4);
- for (j = 0; j < 256; j++)
- {
- png_ptr->gamma_16_to_1[i][j] =
- (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
- 65535.0, g) * 65535.0 + .5);
- }
- }
- g = 1.0 / (png_ptr->screen_gamma);
- png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
- (png_uint_32)(num * sizeof (png_uint_16p)));
- for (i = 0; i < num; i++)
- {
- png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
- (png_uint_32)(256 * sizeof (png_uint_16)));
- ig = (((png_uint_32)i *
- (png_uint_32)png_gamma_shift[shift]) >> 4);
- for (j = 0; j < 256; j++)
- {
- png_ptr->gamma_16_from_1[i][j] =
- (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
- 65535.0, g) * 65535.0 + .5);
- }
- }
- }
- #endif /* PNG_BACKGROUND_SUPPORTED */
- }
- }
- #endif
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