--- /dev/null
+
+/* pngrtran.c - transforms the data in a row for PNG readers
+ *
+ * Last changed in libpng 1.2.27 [April 29, 2008]
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This file contains functions optionally called by an application
+ * in order to tell libpng how to handle data when reading a PNG.
+ * Transformations that are used in both reading and writing are
+ * in pngtrans.c.
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#if defined(PNG_READ_SUPPORTED)
+
+/* Set the action on getting a CRC error for an ancillary or critical chunk. */
+void PNGAPI
+png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
+{
+ png_debug(1, "in png_set_crc_action\n");
+ /* Tell libpng how we react to CRC errors in critical chunks */
+ if(png_ptr == NULL) return;
+ switch (crit_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* leave setting as is */
+ break;
+ case PNG_CRC_WARN_USE: /* warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
+ break;
+ case PNG_CRC_QUIET_USE: /* quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
+ PNG_FLAG_CRC_CRITICAL_IGNORE;
+ break;
+ case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */
+ png_warning(png_ptr, "Can't discard critical data on CRC error.");
+ case PNG_CRC_ERROR_QUIT: /* error/quit */
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
+ break;
+ }
+
+ switch (ancil_action)
+ {
+ case PNG_CRC_NO_CHANGE: /* leave setting as is */
+ break;
+ case PNG_CRC_WARN_USE: /* warn/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
+ break;
+ case PNG_CRC_QUIET_USE: /* quiet/use data */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
+ PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+ case PNG_CRC_ERROR_QUIT: /* error/quit */
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
+ break;
+ case PNG_CRC_WARN_DISCARD: /* warn/discard data */
+ case PNG_CRC_DEFAULT:
+ default:
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
+ break;
+ }
+}
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+ defined(PNG_FLOATING_POINT_SUPPORTED)
+/* handle alpha and tRNS via a background color */
+void PNGAPI
+png_set_background(png_structp png_ptr,
+ png_color_16p background_color, int background_gamma_code,
+ int need_expand, double background_gamma)
+{
+ png_debug(1, "in png_set_background\n");
+ if(png_ptr == NULL) return;
+ if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
+ {
+ png_warning(png_ptr, "Application must supply a known background gamma");
+ return;
+ }
+
+ png_ptr->transformations |= PNG_BACKGROUND;
+ png_memcpy(&(png_ptr->background), background_color,
+ png_sizeof(png_color_16));
+ png_ptr->background_gamma = (float)background_gamma;
+ png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
+ png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
+}
+#endif
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+/* strip 16 bit depth files to 8 bit depth */
+void PNGAPI
+png_set_strip_16(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_strip_16\n");
+ if(png_ptr == NULL) return;
+ png_ptr->transformations |= PNG_16_TO_8;
+}
+#endif
+
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+void PNGAPI
+png_set_strip_alpha(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_strip_alpha\n");
+ if(png_ptr == NULL) return;
+ png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
+}
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+/* Dither file to 8 bit. Supply a palette, the current number
+ * of elements in the palette, the maximum number of elements
+ * allowed, and a histogram if possible. If the current number
+ * of colors is greater then the maximum number, the palette will be
+ * modified to fit in the maximum number. "full_dither" indicates
+ * whether we need a dithering cube set up for RGB images, or if we
+ * simply are reducing the number of colors in a paletted image.
+ */
+
+typedef struct png_dsort_struct
+{
+ struct png_dsort_struct FAR * next;
+ png_byte left;
+ png_byte right;
+} png_dsort;
+typedef png_dsort FAR * png_dsortp;
+typedef png_dsort FAR * FAR * png_dsortpp;
+
+void PNGAPI
+png_set_dither(png_structp png_ptr, png_colorp palette,
+ int num_palette, int maximum_colors, png_uint_16p histogram,
+ int full_dither)
+{
+ png_debug(1, "in png_set_dither\n");
+ if(png_ptr == NULL) return;
+ png_ptr->transformations |= PNG_DITHER;
+
+ if (!full_dither)
+ {
+ int i;
+
+ png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof (png_byte)));
+ for (i = 0; i < num_palette; i++)
+ png_ptr->dither_index[i] = (png_byte)i;
+ }
+
+ if (num_palette > maximum_colors)
+ {
+ if (histogram != NULL)
+ {
+ /* This is easy enough, just throw out the least used colors.
+ Perhaps not the best solution, but good enough. */
+
+ int i;
+
+ /* initialize an array to sort colors */
+ png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof (png_byte)));
+
+ /* initialize the dither_sort array */
+ for (i = 0; i < num_palette; i++)
+ png_ptr->dither_sort[i] = (png_byte)i;
+
+ /* Find the least used palette entries by starting a
+ bubble sort, and running it until we have sorted
+ out enough colors. Note that we don't care about
+ sorting all the colors, just finding which are
+ least used. */
+
+ for (i = num_palette - 1; i >= maximum_colors; i--)
+ {
+ int done; /* to stop early if the list is pre-sorted */
+ int j;
+
+ done = 1;
+ for (j = 0; j < i; j++)
+ {
+ if (histogram[png_ptr->dither_sort[j]]
+ < histogram[png_ptr->dither_sort[j + 1]])
+ {
+ png_byte t;
+
+ t = png_ptr->dither_sort[j];
+ png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
+ png_ptr->dither_sort[j + 1] = t;
+ done = 0;
+ }
+ }
+ if (done)
+ break;
+ }
+
+ /* swap the palette around, and set up a table, if necessary */
+ if (full_dither)
+ {
+ int j = num_palette;
+
+ /* put all the useful colors within the max, but don't
+ move the others */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ if ((int)png_ptr->dither_sort[i] >= maximum_colors)
+ {
+ do
+ j--;
+ while ((int)png_ptr->dither_sort[j] >= maximum_colors);
+ palette[i] = palette[j];
+ }
+ }
+ }
+ else
+ {
+ int j = num_palette;
+
+ /* move all the used colors inside the max limit, and
+ develop a translation table */
+ for (i = 0; i < maximum_colors; i++)
+ {
+ /* only move the colors we need to */
+ if ((int)png_ptr->dither_sort[i] >= maximum_colors)
+ {
+ png_color tmp_color;
+
+ do
+ j--;
+ while ((int)png_ptr->dither_sort[j] >= maximum_colors);
+
+ tmp_color = palette[j];
+ palette[j] = palette[i];
+ palette[i] = tmp_color;
+ /* indicate where the color went */
+ png_ptr->dither_index[j] = (png_byte)i;
+ png_ptr->dither_index[i] = (png_byte)j;
+ }
+ }
+
+ /* find closest color for those colors we are not using */
+ for (i = 0; i < num_palette; i++)
+ {
+ if ((int)png_ptr->dither_index[i] >= maximum_colors)
+ {
+ int min_d, k, min_k, d_index;
+
+ /* find the closest color to one we threw out */
+ d_index = png_ptr->dither_index[i];
+ min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
+ for (k = 1, min_k = 0; k < maximum_colors; k++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[d_index], palette[k]);
+
+ if (d < min_d)
+ {
+ min_d = d;
+ min_k = k;
+ }
+ }
+ /* point to closest color */
+ png_ptr->dither_index[i] = (png_byte)min_k;
+ }
+ }
+ }
+ png_free(png_ptr, png_ptr->dither_sort);
+ png_ptr->dither_sort=NULL;
+ }
+ else
+ {
+ /* This is much harder to do simply (and quickly). Perhaps
+ we need to go through a median cut routine, but those
+ don't always behave themselves with only a few colors
+ as input. So we will just find the closest two colors,
+ and throw out one of them (chosen somewhat randomly).
+ [We don't understand this at all, so if someone wants to
+ work on improving it, be our guest - AED, GRP]
+ */
+ int i;
+ int max_d;
+ int num_new_palette;
+ png_dsortp t;
+ png_dsortpp hash;
+
+ t=NULL;
+
+ /* initialize palette index arrays */
+ png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof (png_byte)));
+ png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)(num_palette * png_sizeof (png_byte)));
+
+ /* initialize the sort array */
+ for (i = 0; i < num_palette; i++)
+ {
+ png_ptr->index_to_palette[i] = (png_byte)i;
+ png_ptr->palette_to_index[i] = (png_byte)i;
+ }
+
+ hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
+ png_sizeof (png_dsortp)));
+ for (i = 0; i < 769; i++)
+ hash[i] = NULL;
+/* png_memset(hash, 0, 769 * png_sizeof (png_dsortp)); */
+
+ num_new_palette = num_palette;
+
+ /* initial wild guess at how far apart the farthest pixel
+ pair we will be eliminating will be. Larger
+ numbers mean more areas will be allocated, Smaller
+ numbers run the risk of not saving enough data, and
+ having to do this all over again.
+
+ I have not done extensive checking on this number.
+ */
+ max_d = 96;
+
+ while (num_new_palette > maximum_colors)
+ {
+ for (i = 0; i < num_new_palette - 1; i++)
+ {
+ int j;
+
+ for (j = i + 1; j < num_new_palette; j++)
+ {
+ int d;
+
+ d = PNG_COLOR_DIST(palette[i], palette[j]);
+
+ if (d <= max_d)
+ {
+
+ t = (png_dsortp)png_malloc_warn(png_ptr,
+ (png_uint_32)(png_sizeof(png_dsort)));
+ if (t == NULL)
+ break;
+ t->next = hash[d];
+ t->left = (png_byte)i;
+ t->right = (png_byte)j;
+ hash[d] = t;
+ }
+ }
+ if (t == NULL)
+ break;
+ }
+
+ if (t != NULL)
+ for (i = 0; i <= max_d; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p;
+
+ for (p = hash[i]; p; p = p->next)
+ {
+ if ((int)png_ptr->index_to_palette[p->left]
+ < num_new_palette &&
+ (int)png_ptr->index_to_palette[p->right]
+ < num_new_palette)
+ {
+ int j, next_j;
+
+ if (num_new_palette & 0x01)
+ {
+ j = p->left;
+ next_j = p->right;
+ }
+ else
+ {
+ j = p->right;
+ next_j = p->left;
+ }
+
+ num_new_palette--;
+ palette[png_ptr->index_to_palette[j]]
+ = palette[num_new_palette];
+ if (!full_dither)
+ {
+ int k;
+
+ for (k = 0; k < num_palette; k++)
+ {
+ if (png_ptr->dither_index[k] ==
+ png_ptr->index_to_palette[j])
+ png_ptr->dither_index[k] =
+ png_ptr->index_to_palette[next_j];
+ if ((int)png_ptr->dither_index[k] ==
+ num_new_palette)
+ png_ptr->dither_index[k] =
+ png_ptr->index_to_palette[j];
+ }
+ }
+
+ png_ptr->index_to_palette[png_ptr->palette_to_index
+ [num_new_palette]] = png_ptr->index_to_palette[j];
+ png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
+ = png_ptr->palette_to_index[num_new_palette];
+
+ png_ptr->index_to_palette[j] = (png_byte)num_new_palette;
+ png_ptr->palette_to_index[num_new_palette] = (png_byte)j;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ if (num_new_palette <= maximum_colors)
+ break;
+ }
+ }
+
+ for (i = 0; i < 769; i++)
+ {
+ if (hash[i] != NULL)
+ {
+ png_dsortp p = hash[i];
+ while (p)
+ {
+ t = p->next;
+ png_free(png_ptr, p);
+ p = t;
+ }
+ }
+ hash[i] = 0;
+ }
+ max_d += 96;
+ }
+ png_free(png_ptr, hash);
+ png_free(png_ptr, png_ptr->palette_to_index);
+ png_free(png_ptr, png_ptr->index_to_palette);
+ png_ptr->palette_to_index=NULL;
+ png_ptr->index_to_palette=NULL;
+ }
+ num_palette = maximum_colors;
+ }
+ if (png_ptr->palette == NULL)
+ {
+ png_ptr->palette = palette;
+ }
+ png_ptr->num_palette = (png_uint_16)num_palette;
+
+ if (full_dither)
+ {
+ int i;
+ png_bytep distance;
+ int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
+ PNG_DITHER_BLUE_BITS;
+ int num_red = (1 << PNG_DITHER_RED_BITS);
+ int num_green = (1 << PNG_DITHER_GREEN_BITS);
+ int num_blue = (1 << PNG_DITHER_BLUE_BITS);
+ png_size_t num_entries = ((png_size_t)1 << total_bits);
+
+ png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr,
+ (png_uint_32)(num_entries * png_sizeof (png_byte)));
+
+ png_memset(png_ptr->palette_lookup, 0, num_entries *
+ png_sizeof (png_byte));
+
+ distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
+ png_sizeof(png_byte)));
+
+ png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
+
+ for (i = 0; i < num_palette; i++)
+ {
+ int ir, ig, ib;
+ int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
+ int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
+ int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));
+
+ for (ir = 0; ir < num_red; ir++)
+ {
+ /* int dr = abs(ir - r); */
+ int dr = ((ir > r) ? ir - r : r - ir);
+ int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS));
+
+ for (ig = 0; ig < num_green; ig++)
+ {
+ /* int dg = abs(ig - g); */
+ int dg = ((ig > g) ? ig - g : g - ig);
+ int dt = dr + dg;
+ int dm = ((dr > dg) ? dr : dg);
+ int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS);
+
+ for (ib = 0; ib < num_blue; ib++)
+ {
+ int d_index = index_g | ib;
+ /* int db = abs(ib - b); */
+ int db = ((ib > b) ? ib - b : b - ib);
+ int dmax = ((dm > db) ? dm : db);
+ int d = dmax + dt + db;
+
+ if (d < (int)distance[d_index])
+ {
+ distance[d_index] = (png_byte)d;
+ png_ptr->palette_lookup[d_index] = (png_byte)i;
+ }
+ }
+ }
+ }
+ }
+
+ png_free(png_ptr, distance);
+ }
+}
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
+/* Transform the image from the file_gamma to the screen_gamma. We
+ * only do transformations on images where the file_gamma and screen_gamma
+ * are not close reciprocals, otherwise it slows things down slightly, and
+ * also needlessly introduces small errors.
+ *
+ * We will turn off gamma transformation later if no semitransparent entries
+ * are present in the tRNS array for palette images. We can't do it here
+ * because we don't necessarily have the tRNS chunk yet.
+ */
+void PNGAPI
+png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
+{
+ png_debug(1, "in png_set_gamma\n");
+ if(png_ptr == NULL) return;
+ if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
+ png_ptr->transformations |= PNG_GAMMA;
+ png_ptr->gamma = (float)file_gamma;
+ png_ptr->screen_gamma = (float)scrn_gamma;
+}
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+/* Expand paletted images to RGB, expand grayscale images of
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks
+ * to alpha channels.
+ */
+void PNGAPI
+png_set_expand(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_expand\n");
+ if(png_ptr == NULL) return;
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+
+/* GRR 19990627: the following three functions currently are identical
+ * to png_set_expand(). However, it is entirely reasonable that someone
+ * might wish to expand an indexed image to RGB but *not* expand a single,
+ * fully transparent palette entry to a full alpha channel--perhaps instead
+ * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace
+ * the transparent color with a particular RGB value, or drop tRNS entirely.
+ * IOW, a future version of the library may make the transformations flag
+ * a bit more fine-grained, with separate bits for each of these three
+ * functions.
+ *
+ * More to the point, these functions make it obvious what libpng will be
+ * doing, whereas "expand" can (and does) mean any number of things.
+ *
+ * GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified
+ * to expand only the sample depth but not to expand the tRNS to alpha.
+ */
+
+/* Expand paletted images to RGB. */
+void PNGAPI
+png_set_palette_to_rgb(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_palette_to_rgb\n");
+ if(png_ptr == NULL) return;
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+
+#if !defined(PNG_1_0_X)
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+void PNGAPI
+png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_expand_gray_1_2_4_to_8\n");
+ if(png_ptr == NULL) return;
+ png_ptr->transformations |= PNG_EXPAND;
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+#endif
+
+#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */
+/* Deprecated as of libpng-1.2.9 */
+void PNGAPI
+png_set_gray_1_2_4_to_8(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_gray_1_2_4_to_8\n");
+ if(png_ptr == NULL) return;
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+}
+#endif
+
+
+/* Expand tRNS chunks to alpha channels. */
+void PNGAPI
+png_set_tRNS_to_alpha(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_tRNS_to_alpha\n");
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+void PNGAPI
+png_set_gray_to_rgb(png_structp png_ptr)
+{
+ png_debug(1, "in png_set_gray_to_rgb\n");
+ png_ptr->transformations |= PNG_GRAY_TO_RGB;
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
+}
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+#if defined(PNG_FLOATING_POINT_SUPPORTED)
+/* Convert a RGB image to a grayscale of the same width. This allows us,
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
+ */
+
+void PNGAPI
+png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
+ double green)
+{
+ int red_fixed = (int)((float)red*100000.0 + 0.5);
+ int green_fixed = (int)((float)green*100000.0 + 0.5);
+ if(png_ptr == NULL) return;
+ png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
+}
+#endif
+
+void PNGAPI
+png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
+ png_fixed_point red, png_fixed_point green)
+{
+ png_debug(1, "in png_set_rgb_to_gray\n");
+ if(png_ptr == NULL) return;
+ switch(error_action)
+ {
+ case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
+ break;
+ case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
+ break;
+ case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
+ }
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+ png_ptr->transformations |= PNG_EXPAND;
+#else
+ {
+ png_warning(png_ptr, "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
+ png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
+ }
+#endif
+ {
+ png_uint_16 red_int, green_int;
+ if(red < 0 || green < 0)
+ {
+ red_int = 6968; /* .212671 * 32768 + .5 */
+ green_int = 23434; /* .715160 * 32768 + .5 */
+ }
+ else if(red + green < 100000L)
+ {
+ red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
+ green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
+ }
+ else
+ {
+ png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
+ red_int = 6968;
+ green_int = 23434;
+ }
+ png_ptr->rgb_to_gray_red_coeff = red_int;
+ png_ptr->rgb_to_gray_green_coeff = green_int;
+ png_ptr->rgb_to_gray_blue_coeff = (png_uint_16)(32768-red_int-green_int);
+ }
+}
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
+ defined(PNG_LEGACY_SUPPORTED)
+void PNGAPI
+png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
+ read_user_transform_fn)
+{
+ png_debug(1, "in png_set_read_user_transform_fn\n");
+ if(png_ptr == NULL) return;
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+ png_ptr->transformations |= PNG_USER_TRANSFORM;
+ png_ptr->read_user_transform_fn = read_user_transform_fn;
+#endif
+#ifdef PNG_LEGACY_SUPPORTED
+ if(read_user_transform_fn)
+ png_warning(png_ptr,
+ "This version of libpng does not support user transforms");
+#endif
+}
+#endif
+
+/* Initialize everything needed for the read. This includes modifying
+ * the palette.
+ */
+void /* PRIVATE */
+png_init_read_transformations(png_structp png_ptr)
+{
+ png_debug(1, "in png_init_read_transformations\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ if(png_ptr != NULL)
+#endif
+ {
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \
+ || defined(PNG_READ_GAMMA_SUPPORTED)
+ int color_type = png_ptr->color_type;
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+ /* Detect gray background and attempt to enable optimization
+ * for gray --> RGB case */
+ /* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+ * RGB_ALPHA (in which case need_expand is superfluous anyway), the
+ * background color might actually be gray yet not be flagged as such.
+ * This is not a problem for the current code, which uses
+ * PNG_BACKGROUND_IS_GRAY only to decide when to do the
+ * png_do_gray_to_rgb() transformation.
+ */
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+ !(color_type & PNG_COLOR_MASK_COLOR))
+ {
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ } else if ((png_ptr->transformations & PNG_BACKGROUND) &&
+ !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+ (png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ png_ptr->background.red == png_ptr->background.green &&
+ png_ptr->background.red == png_ptr->background.blue)
+ {
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
+ png_ptr->background.gray = png_ptr->background.red;
+ }
+#endif
+
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
+ (png_ptr->transformations & PNG_EXPAND))
+ {
+ if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
+ {
+ /* expand background and tRNS chunks */
+ switch (png_ptr->bit_depth)
+ {
+ case 1:
+ png_ptr->background.gray *= (png_uint_16)0xff;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+ {
+ png_ptr->trans_values.gray *= (png_uint_16)0xff;
+ png_ptr->trans_values.red = png_ptr->trans_values.green
+ = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
+ }
+ break;
+ case 2:
+ png_ptr->background.gray *= (png_uint_16)0x55;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+ {
+ png_ptr->trans_values.gray *= (png_uint_16)0x55;
+ png_ptr->trans_values.red = png_ptr->trans_values.green
+ = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
+ }
+ break;
+ case 4:
+ png_ptr->background.gray *= (png_uint_16)0x11;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+ {
+ png_ptr->trans_values.gray *= (png_uint_16)0x11;
+ png_ptr->trans_values.red = png_ptr->trans_values.green
+ = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
+ }
+ break;
+ case 8:
+ case 16:
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ break;
+ }
+ }
+ else if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_ptr->background.red =
+ png_ptr->palette[png_ptr->background.index].red;
+ png_ptr->background.green =
+ png_ptr->palette[png_ptr->background.index].green;
+ png_ptr->background.blue =
+ png_ptr->palette[png_ptr->background.index].blue;
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)
+ {
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
+#endif
+ {
+ /* invert the alpha channel (in tRNS) unless the pixels are
+ going to be expanded, in which case leave it for later */
+ int i,istop;
+ istop=(int)png_ptr->num_trans;
+ for (i=0; i<istop; i++)
+ png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
+ }
+ }
+#endif
+
+ }
+ }
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)
+ png_ptr->background_1 = png_ptr->background;
+#endif
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
+
+ if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
+ && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
+ < PNG_GAMMA_THRESHOLD))
+ {
+ int i,k;
+ k=0;
+ for (i=0; i<png_ptr->num_trans; i++)
+ {
+ if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
+ k=1; /* partial transparency is present */
+ }
+ if (k == 0)
+ png_ptr->transformations &= ~PNG_GAMMA;
+ }
+
+ if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
+ png_ptr->gamma != 0.0)
+ {
+ png_build_gamma_table(png_ptr);
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->transformations & PNG_BACKGROUND)
+ {
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ /* could skip if no transparency and
+ */
+ png_color back, back_1;
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
+ {
+ back.red = png_ptr->gamma_table[png_ptr->background.red];
+ back.green = png_ptr->gamma_table[png_ptr->background.green];
+ back.blue = png_ptr->gamma_table[png_ptr->background.blue];
+
+ back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
+ back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
+ back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
+ }
+ else
+ {
+ double g, gs;
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = (png_ptr->screen_gamma);
+ gs = 1.0;
+ break;
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = 1.0 / (png_ptr->gamma);
+ gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+ break;
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = 1.0 / (png_ptr->background_gamma);
+ gs = 1.0 / (png_ptr->background_gamma *
+ png_ptr->screen_gamma);
+ break;
+ default:
+ g = 1.0; /* back_1 */
+ gs = 1.0; /* back */
+ }
+
+ if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)
+ {
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+ }
+ else
+ {
+ back.red = (png_byte)(pow(
+ (double)png_ptr->background.red/255, gs) * 255.0 + .5);
+ back.green = (png_byte)(pow(
+ (double)png_ptr->background.green/255, gs) * 255.0 + .5);
+ back.blue = (png_byte)(pow(
+ (double)png_ptr->background.blue/255, gs) * 255.0 + .5);
+ }
+
+ back_1.red = (png_byte)(pow(
+ (double)png_ptr->background.red/255, g) * 255.0 + .5);
+ back_1.green = (png_byte)(pow(
+ (double)png_ptr->background.green/255, g) * 255.0 + .5);
+ back_1.blue = (png_byte)(pow(
+ (double)png_ptr->background.blue/255, g) * 255.0 + .5);
+ }
+ for (i = 0; i < num_palette; i++)
+ {
+ if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
+ {
+ if (png_ptr->trans[i] == 0)
+ {
+ palette[i] = back;
+ }
+ else /* if (png_ptr->trans[i] != 0xff) */
+ {
+ png_byte v, w;
+
+ v = png_ptr->gamma_to_1[palette[i].red];
+ png_composite(w, v, png_ptr->trans[i], back_1.red);
+ palette[i].red = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].green];
+ png_composite(w, v, png_ptr->trans[i], back_1.green);
+ palette[i].green = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[palette[i].blue];
+ png_composite(w, v, png_ptr->trans[i], back_1.blue);
+ palette[i].blue = png_ptr->gamma_from_1[w];
+ }
+ }
+ else
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+ }
+ /* Prevent the transformations being done again, and make sure
+ * that the now spurious alpha channel is stripped - the code
+ * has just reduced background composition and gamma correction
+ * to a simple alpha channel strip.
+ */
+ png_ptr->transformations &= ~PNG_BACKGROUND;
+ png_ptr->transformations &= ~PNG_GAMMA;
+ png_ptr->transformations |= PNG_STRIP_ALPHA;
+ }
+ /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
+ else
+ /* color_type != PNG_COLOR_TYPE_PALETTE */
+ {
+ double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1);
+ double g = 1.0;
+ double gs = 1.0;
+
+ switch (png_ptr->background_gamma_type)
+ {
+ case PNG_BACKGROUND_GAMMA_SCREEN:
+ g = (png_ptr->screen_gamma);
+ gs = 1.0;
+ break;
+ case PNG_BACKGROUND_GAMMA_FILE:
+ g = 1.0 / (png_ptr->gamma);
+ gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+ break;
+ case PNG_BACKGROUND_GAMMA_UNIQUE:
+ g = 1.0 / (png_ptr->background_gamma);
+ gs = 1.0 / (png_ptr->background_gamma *
+ png_ptr->screen_gamma);
+ break;
+ }
+
+ png_ptr->background_1.gray = (png_uint_16)(pow(
+ (double)png_ptr->background.gray / m, g) * m + .5);
+ png_ptr->background.gray = (png_uint_16)(pow(
+ (double)png_ptr->background.gray / m, gs) * m + .5);
+
+ if ((png_ptr->background.red != png_ptr->background.green) ||
+ (png_ptr->background.red != png_ptr->background.blue) ||
+ (png_ptr->background.red != png_ptr->background.gray))
+ {
+ /* RGB or RGBA with color background */
+ png_ptr->background_1.red = (png_uint_16)(pow(
+ (double)png_ptr->background.red / m, g) * m + .5);
+ png_ptr->background_1.green = (png_uint_16)(pow(
+ (double)png_ptr->background.green / m, g) * m + .5);
+ png_ptr->background_1.blue = (png_uint_16)(pow(
+ (double)png_ptr->background.blue / m, g) * m + .5);
+ png_ptr->background.red = (png_uint_16)(pow(
+ (double)png_ptr->background.red / m, gs) * m + .5);
+ png_ptr->background.green = (png_uint_16)(pow(
+ (double)png_ptr->background.green / m, gs) * m + .5);
+ png_ptr->background.blue = (png_uint_16)(pow(
+ (double)png_ptr->background.blue / m, gs) * m + .5);
+ }
+ else
+ {
+ /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
+ png_ptr->background_1.red = png_ptr->background_1.green
+ = png_ptr->background_1.blue = png_ptr->background_1.gray;
+ png_ptr->background.red = png_ptr->background.green
+ = png_ptr->background.blue = png_ptr->background.gray;
+ }
+ }
+ }
+ else
+ /* transformation does not include PNG_BACKGROUND */
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+ if (color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_colorp palette = png_ptr->palette;
+ int num_palette = png_ptr->num_palette;
+ int i;
+
+ for (i = 0; i < num_palette; i++)
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+
+ /* Done the gamma correction. */
+ png_ptr->transformations &= ~PNG_GAMMA;
+ }
+ }
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ else
+#endif
+#endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ /* No GAMMA transformation */
+ if ((png_ptr->transformations & PNG_BACKGROUND) &&
+ (color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ int i;
+ int istop = (int)png_ptr->num_trans;
+ png_color back;
+ png_colorp palette = png_ptr->palette;
+
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+
+ for (i = 0; i < istop; i++)
+ {
+ if (png_ptr->trans[i] == 0)
+ {
+ palette[i] = back;
+ }
+ else if (png_ptr->trans[i] != 0xff)
+ {
+ /* The png_composite() macro is defined in png.h */
+ png_composite(palette[i].red, palette[i].red,
+ png_ptr->trans[i], back.red);
+ png_composite(palette[i].green, palette[i].green,
+ png_ptr->trans[i], back.green);
+ png_composite(palette[i].blue, palette[i].blue,
+ png_ptr->trans[i], back.blue);
+ }
+ }
+
+ /* Handled alpha, still need to strip the channel. */
+ png_ptr->transformations &= ~PNG_BACKGROUND;
+ png_ptr->transformations |= PNG_STRIP_ALPHA;
+ }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */
+
+#if defined(PNG_READ_SHIFT_SUPPORTED)
+ if ((png_ptr->transformations & PNG_SHIFT) &&
+ (color_type == PNG_COLOR_TYPE_PALETTE))
+ {
+ png_uint_16 i;
+ png_uint_16 istop = png_ptr->num_palette;
+ int sr = 8 - png_ptr->sig_bit.red;
+ int sg = 8 - png_ptr->sig_bit.green;
+ int sb = 8 - png_ptr->sig_bit.blue;
+
+ if (sr < 0 || sr > 8)
+ sr = 0;
+ if (sg < 0 || sg > 8)
+ sg = 0;
+ if (sb < 0 || sb > 8)
+ sb = 0;
+ for (i = 0; i < istop; i++)
+ {
+ png_ptr->palette[i].red >>= sr;
+ png_ptr->palette[i].green >>= sg;
+ png_ptr->palette[i].blue >>= sb;
+ }
+ }
+#endif /* PNG_READ_SHIFT_SUPPORTED */
+ }
+#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \
+ && !defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if(png_ptr)
+ return;
+#endif
+}
+
+/* Modify the info structure to reflect the transformations. The
+ * info should be updated so a PNG file could be written with it,
+ * assuming the transformations result in valid PNG data.
+ */
+void /* PRIVATE */
+png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
+{
+ png_debug(1, "in png_read_transform_info\n");
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (png_ptr->num_trans &&
+ (png_ptr->transformations & PNG_EXPAND_tRNS))
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ else
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB;
+ info_ptr->bit_depth = 8;
+ info_ptr->num_trans = 0;
+ }
+ else
+ {
+ if (png_ptr->num_trans)
+ {
+ if (png_ptr->transformations & PNG_EXPAND_tRNS)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+#if 0 /* Removed from libpng-1.2.27 */
+ else
+ info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
+#endif
+ }
+ if (info_ptr->bit_depth < 8)
+ info_ptr->bit_depth = 8;
+ info_ptr->num_trans = 0;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->transformations & PNG_BACKGROUND)
+ {
+ info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
+ info_ptr->num_trans = 0;
+ info_ptr->background = png_ptr->background;
+ }
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (png_ptr->transformations & PNG_GAMMA)
+ {
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+ info_ptr->gamma = png_ptr->gamma;
+#endif
+#ifdef PNG_FIXED_POINT_SUPPORTED
+ info_ptr->int_gamma = png_ptr->int_gamma;
+#endif
+ }
+#endif
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+ if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
+ info_ptr->bit_depth = 8;
+#endif
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+ if (png_ptr->transformations & PNG_GRAY_TO_RGB)
+ info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+ info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+ if (png_ptr->transformations & PNG_DITHER)
+ {
+ if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
+ png_ptr->palette_lookup && info_ptr->bit_depth == 8)
+ {
+ info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
+ }
+ }
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED)
+ if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
+ info_ptr->bit_depth = 8;
+#endif
+
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ info_ptr->channels = 1;
+ else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ info_ptr->channels = 3;
+ else
+ info_ptr->channels = 1;
+
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+ if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
+ info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
+#endif
+
+ if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
+ info_ptr->channels++;
+
+#if defined(PNG_READ_FILLER_SUPPORTED)
+ /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
+ if ((png_ptr->transformations & PNG_FILLER) &&
+ ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
+ (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
+ {
+ info_ptr->channels++;
+ /* if adding a true alpha channel not just filler */
+#if !defined(PNG_1_0_X)
+ if (png_ptr->transformations & PNG_ADD_ALPHA)
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
+#endif
+ }
+#endif
+
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \
+defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+ if(png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ if(info_ptr->bit_depth < png_ptr->user_transform_depth)
+ info_ptr->bit_depth = png_ptr->user_transform_depth;
+ if(info_ptr->channels < png_ptr->user_transform_channels)
+ info_ptr->channels = png_ptr->user_transform_channels;
+ }
+#endif
+
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels *
+ info_ptr->bit_depth);
+
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth,info_ptr->width);
+
+#if !defined(PNG_READ_EXPAND_SUPPORTED)
+ if(png_ptr)
+ return;
+#endif
+}
+
+/* Transform the row. The order of transformations is significant,
+ * and is very touchy. If you add a transformation, take care to
+ * decide how it fits in with the other transformations here.
+ */
+void /* PRIVATE */
+png_do_read_transformations(png_structp png_ptr)
+{
+ png_debug(1, "in png_do_read_transformations\n");
+ if (png_ptr->row_buf == NULL)
+ {
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+ char msg[50];
+
+ png_snprintf2(msg, 50,
+ "NULL row buffer for row %ld, pass %d", png_ptr->row_number,
+ png_ptr->pass);
+ png_error(png_ptr, msg);
+#else
+ png_error(png_ptr, "NULL row buffer");
+#endif
+ }
+#ifdef PNG_WARN_UNINITIALIZED_ROW
+ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
+ /* Application has failed to call either png_read_start_image()
+ * or png_read_update_info() after setting transforms that expand
+ * pixels. This check added to libpng-1.2.19 */
+#if (PNG_WARN_UNINITIALIZED_ROW==1)
+ png_error(png_ptr, "Uninitialized row");
+#else
+ png_warning(png_ptr, "Uninitialized row");
+#endif
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+ if (png_ptr->transformations & PNG_EXPAND)
+ {
+ if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
+ }
+ else
+ {
+ if (png_ptr->num_trans &&
+ (png_ptr->transformations & PNG_EXPAND_tRNS))
+ png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ &(png_ptr->trans_values));
+ else
+ png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ NULL);
+ }
+ }
+#endif
+
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+ if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
+ png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if (png_ptr->transformations & PNG_RGB_TO_GRAY)
+ {
+ int rgb_error =
+ png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
+ if(rgb_error)
+ {
+ png_ptr->rgb_to_gray_status=1;
+ if((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_WARN)
+ png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+ if((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ PNG_RGB_TO_GRAY_ERR)
+ png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
+ }
+ }
+#endif
+
+/*
+From Andreas Dilger e-mail to png-implement, 26 March 1998:
+
+ In most cases, the "simple transparency" should be done prior to doing
+ gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ pixel is transparent. You would also need to make sure that the
+ transparency information is upgraded to RGB.
+
+ To summarize, the current flow is:
+ - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ with background "in place" if transparent,
+ convert to RGB if necessary
+ - Gray + alpha -> composite with gray background and remove alpha bytes,
+ convert to RGB if necessary
+
+ To support RGB backgrounds for gray images we need:
+ - Gray + simple transparency -> convert to RGB + simple transparency, compare
+ 3 or 6 bytes and composite with background
+ "in place" if transparent (3x compare/pixel
+ compared to doing composite with gray bkgrnd)
+ - Gray + alpha -> convert to RGB + alpha, composite with background and
+ remove alpha bytes (3x float operations/pixel
+ compared with composite on gray background)
+
+ Greg's change will do this. The reason it wasn't done before is for
+ performance, as this increases the per-pixel operations. If we would check
+ in advance if the background was gray or RGB, and position the gray-to-RGB
+ transform appropriately, then it would save a lot of work/time.
+ */
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+ /* if gray -> RGB, do so now only if background is non-gray; else do later
+ * for performance reasons */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+ png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if ((png_ptr->transformations & PNG_BACKGROUND) &&
+ ((png_ptr->num_trans != 0 ) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
+ png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ &(png_ptr->trans_values), &(png_ptr->background)
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ , &(png_ptr->background_1),
+ png_ptr->gamma_table, png_ptr->gamma_from_1,
+ png_ptr->gamma_to_1, png_ptr->gamma_16_table,
+ png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,
+ png_ptr->gamma_shift
+#endif
+);
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if ((png_ptr->transformations & PNG_GAMMA) &&
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ !((png_ptr->transformations & PNG_BACKGROUND) &&
+ ((png_ptr->num_trans != 0) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
+#endif
+ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+ png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->gamma_table, png_ptr->gamma_16_table,
+ png_ptr->gamma_shift);
+#endif
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+ if (png_ptr->transformations & PNG_16_TO_8)
+ png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+ if (png_ptr->transformations & PNG_DITHER)
+ {
+ png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->palette_lookup, png_ptr->dither_index);
+ if(png_ptr->row_info.rowbytes == (png_uint_32)0)
+ png_error(png_ptr, "png_do_dither returned rowbytes=0");
+ }
+#endif
+
+#if defined(PNG_READ_INVERT_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_MONO)
+ png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED)
+ if (png_ptr->transformations & PNG_SHIFT)
+ png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ &(png_ptr->shift));
+#endif
+
+#if defined(PNG_READ_PACK_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACK)
+ png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_BGR_SUPPORTED)
+ if (png_ptr->transformations & PNG_BGR)
+ png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_PACKSWAP)
+ png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+ /* if gray -> RGB, do so now only if we did not do so above */
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
+ png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED)
+ if (png_ptr->transformations & PNG_FILLER)
+ png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
+ (png_uint_32)png_ptr->filler, png_ptr->flags);
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)
+ png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
+ if (png_ptr->transformations & PNG_SWAP_ALPHA)
+ png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_SWAP_SUPPORTED)
+ if (png_ptr->transformations & PNG_SWAP_BYTES)
+ png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)
+ {
+ if(png_ptr->read_user_transform_fn != NULL)
+ (*(png_ptr->read_user_transform_fn)) /* user read transform function */
+ (png_ptr, /* png_ptr */
+ &(png_ptr->row_info), /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_uint_32 rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ if(png_ptr->user_transform_depth)
+ png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
+ if(png_ptr->user_transform_channels)
+ png_ptr->row_info.channels = png_ptr->user_transform_channels;
+#endif
+ png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *
+ png_ptr->row_info.channels);
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+ }
+#endif
+
+}
+
+#if defined(PNG_READ_PACK_SUPPORTED)
+/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
+ * without changing the actual values. Thus, if you had a row with
+ * a bit depth of 1, you would end up with bytes that only contained
+ * the numbers 0 or 1. If you would rather they contain 0 and 255, use
+ * png_do_shift() after this.
+ */
+void /* PRIVATE */
+png_do_unpack(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_unpack\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ if (row != NULL && row_info != NULL && row_info->bit_depth < 8)
+#else
+ if (row_info->bit_depth < 8)
+#endif
+ {
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x01);
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+ case 2:
+ {
+
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x03);
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+ case 4:
+ {
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
+ png_bytep dp = row + (png_size_t)row_width - 1;
+ png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ *dp = (png_byte)((*sp >> shift) & 0x0f);
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_width * row_info->channels;
+ }
+}
+#endif
+
+#if defined(PNG_READ_SHIFT_SUPPORTED)
+/* Reverse the effects of png_do_shift. This routine merely shifts the
+ * pixels back to their significant bits values. Thus, if you have
+ * a row of bit depth 8, but only 5 are significant, this will shift
+ * the values back to 0 through 31.
+ */
+void /* PRIVATE */
+png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
+{
+ png_debug(1, "in png_do_unshift\n");
+ if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL && sig_bits != NULL &&
+#endif
+ row_info->color_type != PNG_COLOR_TYPE_PALETTE)
+ {
+ int shift[4];
+ int channels = 0;
+ int c;
+ png_uint_16 value = 0;
+ png_uint_32 row_width = row_info->width;
+
+ if (row_info->color_type & PNG_COLOR_MASK_COLOR)
+ {
+ shift[channels++] = row_info->bit_depth - sig_bits->red;
+ shift[channels++] = row_info->bit_depth - sig_bits->green;
+ shift[channels++] = row_info->bit_depth - sig_bits->blue;
+ }
+ else
+ {
+ shift[channels++] = row_info->bit_depth - sig_bits->gray;
+ }
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ shift[channels++] = row_info->bit_depth - sig_bits->alpha;
+ }
+
+ for (c = 0; c < channels; c++)
+ {
+ if (shift[c] <= 0)
+ shift[c] = 0;
+ else
+ value = 1;
+ }
+
+ if (!value)
+ return;
+
+ switch (row_info->bit_depth)
+ {
+ case 2:
+ {
+ png_bytep bp;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+
+ for (bp = row, i = 0; i < istop; i++)
+ {
+ *bp >>= 1;
+ *bp++ &= 0x55;
+ }
+ break;
+ }
+ case 4:
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->rowbytes;
+ png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) |
+ (png_byte)((int)0xf >> shift[0]));
+
+ for (i = 0; i < istop; i++)
+ {
+ *bp >>= shift[0];
+ *bp++ &= mask;
+ }
+ break;
+ }
+ case 8:
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_width * channels;
+
+ for (i = 0; i < istop; i++)
+ {
+ *bp++ >>= shift[i%channels];
+ }
+ break;
+ }
+ case 16:
+ {
+ png_bytep bp = row;
+ png_uint_32 i;
+ png_uint_32 istop = channels * row_width;
+
+ for (i = 0; i < istop; i++)
+ {
+ value = (png_uint_16)((*bp << 8) + *(bp + 1));
+ value >>= shift[i%channels];
+ *bp++ = (png_byte)(value >> 8);
+ *bp++ = (png_byte)(value & 0xff);
+ }
+ break;
+ }
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_16_TO_8_SUPPORTED)
+/* chop rows of bit depth 16 down to 8 */
+void /* PRIVATE */
+png_do_chop(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_chop\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ if (row != NULL && row_info != NULL && row_info->bit_depth == 16)
+#else
+ if (row_info->bit_depth == 16)
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ png_uint_32 i;
+ png_uint_32 istop = row_info->width * row_info->channels;
+
+ for (i = 0; i<istop; i++, sp += 2, dp++)
+ {
+#if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED)
+ /* This does a more accurate scaling of the 16-bit color
+ * value, rather than a simple low-byte truncation.
+ *
+ * What the ideal calculation should be:
+ * *dp = (((((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L;
+ *
+ * GRR: no, I think this is what it really should be:
+ * *dp = (((((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L;
+ *
+ * GRR: here's the exact calculation with shifts:
+ * temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L;
+ * *dp = (temp - (temp >> 8)) >> 8;
+ *
+ * Approximate calculation with shift/add instead of multiply/divide:
+ * *dp = ((((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8;
+ *
+ * What we actually do to avoid extra shifting and conversion:
+ */
+
+ *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);
+#else
+ /* Simply discard the low order byte */
+ *dp = *sp;
+#endif
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);
+ row_info->rowbytes = row_info->width * row_info->channels;
+ }
+}
+#endif
+
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
+void /* PRIVATE */
+png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_swap_alpha\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ if (row != NULL && row_info != NULL)
+#endif
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This converts from RGBA to ARGB */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+ /* This converts from RRGGBBAA to AARRGGBB */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This converts from GA to AG */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save;
+ }
+ }
+ /* This converts from GGAA to AAGG */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_byte save[2];
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ save[0] = *(--sp);
+ save[1] = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = save[0];
+ *(--dp) = save[1];
+ }
+ }
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+void /* PRIVATE */
+png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_invert_alpha\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ if (row != NULL && row_info != NULL)
+#endif
+ {
+ png_uint_32 row_width = row_info->width;
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ /* This inverts the alpha channel in RGBA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=3;
+ dp=sp;
+ }
+ }
+ /* This inverts the alpha channel in RRGGBBAA */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+
+/* This does nothing:
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ We can replace it with:
+*/
+ sp-=6;
+ dp=sp;
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ /* This inverts the alpha channel in GA */
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = *(--sp);
+ }
+ }
+ /* This inverts the alpha channel in GGAA */
+ else
+ {
+ png_bytep sp = row + row_info->rowbytes;
+ png_bytep dp = sp;
+ png_uint_32 i;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = (png_byte)(255 - *(--sp));
+ *(--dp) = (png_byte)(255 - *(--sp));
+/*
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+*/
+ sp-=2;
+ dp=sp;
+ }
+ }
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_FILLER_SUPPORTED)
+/* Add filler channel if we have RGB color */
+void /* PRIVATE */
+png_do_read_filler(png_row_infop row_info, png_bytep row,
+ png_uint_32 filler, png_uint_32 flags)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ png_byte hi_filler = (png_byte)((filler>>8) & 0xff);
+ png_byte lo_filler = (png_byte)(filler & 0xff);
+
+ png_debug(1, "in png_do_read_filler\n");
+ if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL &&
+#endif
+ row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if(row_info->bit_depth == 8)
+ {
+ /* This changes the data from G to GX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+ /* This changes the data from G to XG */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 16;
+ row_info->rowbytes = row_width * 2;
+ }
+ }
+ else if(row_info->bit_depth == 16)
+ {
+ /* This changes the data from GG to GGXX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ /* This changes the data from GG to XXGG */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 2;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+ } /* COLOR_TYPE == GRAY */
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if(row_info->bit_depth == 8)
+ {
+ /* This changes the data from RGB to RGBX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 3;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = lo_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ /* This changes the data from RGB to XRGB */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 3;
+ png_bytep dp = sp + (png_size_t)row_width;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 4;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ }
+ }
+ else if(row_info->bit_depth == 16)
+ {
+ /* This changes the data from RRGGBB to RRGGBBXX */
+ if (flags & PNG_FLAG_FILLER_AFTER)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 6;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 1; i < row_width; i++)
+ {
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ }
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+ /* This changes the data from RRGGBB to XXRRGGBB */
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 6;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = *(--sp);
+ *(--dp) = hi_filler;
+ *(--dp) = lo_filler;
+ }
+ row_info->channels = 4;
+ row_info->pixel_depth = 64;
+ row_info->rowbytes = row_width * 8;
+ }
+ }
+ } /* COLOR_TYPE == RGB */
+}
+#endif
+
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+/* expand grayscale files to RGB, with or without alpha */
+void /* PRIVATE */
+png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
+{
+ png_uint_32 i;
+ png_uint_32 row_width = row_info->width;
+
+ png_debug(1, "in png_do_gray_to_rgb\n");
+ if (row_info->bit_depth >= 8 &&
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL &&
+#endif
+ !(row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + (png_size_t)row_width - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 2;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *sp;
+ *(dp--) = *(sp--);
+ }
+ }
+ else
+ {
+ png_bytep sp = row + (png_size_t)row_width * 4 - 1;
+ png_bytep dp = sp + (png_size_t)row_width * 4;
+ for (i = 0; i < row_width; i++)
+ {
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *sp;
+ *(dp--) = *(sp - 1);
+ *(dp--) = *(sp--);
+ *(dp--) = *(sp--);
+ }
+ }
+ }
+ row_info->channels += (png_byte)2;
+ row_info->color_type |= PNG_COLOR_MASK_COLOR;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+ }
+}
+#endif
+
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+/* reduce RGB files to grayscale, with or without alpha
+ * using the equation given in Poynton's ColorFAQ at
+ * <http://www.inforamp.net/~poynton/>
+ * Copyright (c) 1998-01-04 Charles Poynton poynton at inforamp.net
+ *
+ * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B
+ *
+ * We approximate this with
+ *
+ * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
+ *
+ * which can be expressed with integers as
+ *
+ * Y = (6969 * R + 23434 * G + 2365 * B)/32768
+ *
+ * The calculation is to be done in a linear colorspace.
+ *
+ * Other integer coefficents can be used via png_set_rgb_to_gray().
+ */
+int /* PRIVATE */
+png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
+
+{
+ png_uint_32 i;
+
+ png_uint_32 row_width = row_info->width;
+ int rgb_error = 0;
+
+ png_debug(1, "in png_do_rgb_to_gray\n");
+ if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL &&
+#endif
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
+ png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
+ png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ {
+ if (row_info->bit_depth == 8)
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = png_ptr->gamma_to_1[*(sp++)];
+ png_byte green = png_ptr->gamma_to_1[*(sp++)];
+ png_byte blue = png_ptr->gamma_to_1[*(sp++)];
+ if(red != green || red != blue)
+ {
+ rgb_error |= 1;
+ *(dp++) = png_ptr->gamma_from_1[
+ (rc*red+gc*green+bc*blue)>>15];
+ }
+ else
+ *(dp++) = *(sp-1);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+ if(red != green || red != blue)
+ {
+ rgb_error |= 1;
+ *(dp++) = (png_byte)((rc*red+gc*green+bc*blue)>>15);
+ }
+ else
+ *(dp++) = *(sp-1);
+ }
+ }
+ }
+
+ else /* RGB bit_depth == 16 */
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_16_to_1 != NULL &&
+ png_ptr->gamma_16_from_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, w;
+
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+
+ if(red == green && red == blue)
+ w = red;
+ else
+ {
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
+ png_ptr->gamma_shift][red>>8];
+ png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
+ png_ptr->gamma_shift][green>>8];
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
+ png_ptr->gamma_shift][blue>>8];
+ png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
+ + bc*blue_1)>>15);
+ w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+ png_ptr->gamma_shift][gray16 >> 8];
+ rgb_error |= 1;
+ }
+
+ *(dp++) = (png_byte)((w>>8) & 0xff);
+ *(dp++) = (png_byte)(w & 0xff);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, gray16;
+
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+
+ if(red != green || red != blue)
+ rgb_error |= 1;
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
+ *(dp++) = (png_byte)((gray16>>8) & 0xff);
+ *(dp++) = (png_byte)(gray16 & 0xff);
+ }
+ }
+ }
+ }
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ {
+ if (row_info->bit_depth == 8)
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = png_ptr->gamma_to_1[*(sp++)];
+ png_byte green = png_ptr->gamma_to_1[*(sp++)];
+ png_byte blue = png_ptr->gamma_to_1[*(sp++)];
+ if(red != green || red != blue)
+ rgb_error |= 1;
+ *(dp++) = png_ptr->gamma_from_1
+ [(rc*red + gc*green + bc*blue)>>15];
+ *(dp++) = *(sp++); /* alpha */
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_byte red = *(sp++);
+ png_byte green = *(sp++);
+ png_byte blue = *(sp++);
+ if(red != green || red != blue)
+ rgb_error |= 1;
+ *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);
+ *(dp++) = *(sp++); /* alpha */
+ }
+ }
+ }
+ else /* RGBA bit_depth == 16 */
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->gamma_16_to_1 != NULL &&
+ png_ptr->gamma_16_from_1 != NULL)
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, w;
+
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;
+
+ if(red == green && red == blue)
+ w = red;
+ else
+ {
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
+ png_ptr->gamma_shift][red>>8];
+ png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
+ png_ptr->gamma_shift][green>>8];
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
+ png_ptr->gamma_shift][blue>>8];
+ png_uint_16 gray16 = (png_uint_16)((rc * red_1
+ + gc * green_1 + bc * blue_1)>>15);
+ w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
+ png_ptr->gamma_shift][gray16 >> 8];
+ rgb_error |= 1;
+ }
+
+ *(dp++) = (png_byte)((w>>8) & 0xff);
+ *(dp++) = (png_byte)(w & 0xff);
+ *(dp++) = *(sp++); /* alpha */
+ *(dp++) = *(sp++);
+ }
+ }
+ else
+#endif
+ {
+ png_bytep sp = row;
+ png_bytep dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 red, green, blue, gray16;
+ red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+ green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+ blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
+ if(red != green || red != blue)
+ rgb_error |= 1;
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
+ *(dp++) = (png_byte)((gray16>>8) & 0xff);
+ *(dp++) = (png_byte)(gray16 & 0xff);
+ *(dp++) = *(sp++); /* alpha */
+ *(dp++) = *(sp++);
+ }
+ }
+ }
+ }
+ row_info->channels -= (png_byte)2;
+ row_info->color_type &= ~PNG_COLOR_MASK_COLOR;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+ }
+ return rgb_error;
+}
+#endif
+
+/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth
+ * large of png_color. This lets grayscale images be treated as
+ * paletted. Most useful for gamma correction and simplification
+ * of code.
+ */
+void PNGAPI
+png_build_grayscale_palette(int bit_depth, png_colorp palette)
+{
+ int num_palette;
+ int color_inc;
+ int i;
+ int v;
+
+ png_debug(1, "in png_do_build_grayscale_palette\n");
+ if (palette == NULL)
+ return;
+
+ switch (bit_depth)
+ {
+ case 1:
+ num_palette = 2;
+ color_inc = 0xff;
+ break;
+ case 2:
+ num_palette = 4;
+ color_inc = 0x55;
+ break;
+ case 4:
+ num_palette = 16;
+ color_inc = 0x11;
+ break;
+ case 8:
+ num_palette = 256;
+ color_inc = 1;
+ break;
+ default:
+ num_palette = 0;
+ color_inc = 0;
+ break;
+ }
+
+ for (i = 0, v = 0; i < num_palette; i++, v += color_inc)
+ {
+ palette[i].red = (png_byte)v;
+ palette[i].green = (png_byte)v;
+ palette[i].blue = (png_byte)v;
+ }
+}
+
+/* This function is currently unused. Do we really need it? */
+#if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED)
+void /* PRIVATE */
+png_correct_palette(png_structp png_ptr, png_colorp palette,
+ int num_palette)
+{
+ png_debug(1, "in png_correct_palette\n");
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
+ defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
+ if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
+ {
+ png_color back, back_1;
+
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
+ {
+ back.red = png_ptr->gamma_table[png_ptr->background.red];
+ back.green = png_ptr->gamma_table[png_ptr->background.green];
+ back.blue = png_ptr->gamma_table[png_ptr->background.blue];
+
+ back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
+ back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
+ back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
+ }
+ else
+ {
+ double g;
+
+ g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
+
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN ||
+ fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
+ {
+ back.red = png_ptr->background.red;
+ back.green = png_ptr->background.green;
+ back.blue = png_ptr->background.blue;
+ }
+ else
+ {
+ back.red =
+ (png_byte)(pow((double)png_ptr->background.red/255, g) *
+ 255.0 + 0.5);
+ back.green =
+ (png_byte)(pow((double)png_ptr->background.green/255, g) *
+ 255.0 + 0.5);
+ back.blue =
+ (png_byte)(pow((double)png_ptr->background.blue/255, g) *
+ 255.0 + 0.5);
+ }
+
+ g = 1.0 / png_ptr->background_gamma;
+
+ back_1.red =
+ (png_byte)(pow((double)png_ptr->background.red/255, g) *
+ 255.0 + 0.5);
+ back_1.green =
+ (png_byte)(pow((double)png_ptr->background.green/255, g) *
+ 255.0 + 0.5);
+ back_1.blue =
+ (png_byte)(pow((double)png_ptr->background.blue/255, g) *
+ 255.0 + 0.5);
+ }
+
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_uint_32 i;
+
+ for (i = 0; i < (png_uint_32)num_palette; i++)
+ {
+ if (i < png_ptr->num_trans && png_ptr->trans[i] == 0)
+ {
+ palette[i] = back;
+ }
+ else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff)
+ {
+ png_byte v, w;
+
+ v = png_ptr->gamma_to_1[png_ptr->palette[i].red];
+ png_composite(w, v, png_ptr->trans[i], back_1.red);
+ palette[i].red = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[png_ptr->palette[i].green];
+ png_composite(w, v, png_ptr->trans[i], back_1.green);
+ palette[i].green = png_ptr->gamma_from_1[w];
+
+ v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];
+ png_composite(w, v, png_ptr->trans[i], back_1.blue);
+ palette[i].blue = png_ptr->gamma_from_1[w];
+ }
+ else
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+ }
+ }
+ else
+ {
+ int i;
+
+ for (i = 0; i < num_palette; i++)
+ {
+ if (palette[i].red == (png_byte)png_ptr->trans_values.gray)
+ {
+ palette[i] = back;
+ }
+ else
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+ }
+ }
+ }
+ else
+#endif
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (png_ptr->transformations & PNG_GAMMA)
+ {
+ int i;
+
+ for (i = 0; i < num_palette; i++)
+ {
+ palette[i].red = png_ptr->gamma_table[palette[i].red];
+ palette[i].green = png_ptr->gamma_table[palette[i].green];
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];
+ }
+ }
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ else
+#endif
+#endif
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ if (png_ptr->transformations & PNG_BACKGROUND)
+ {
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ png_color back;
+
+ back.red = (png_byte)png_ptr->background.red;
+ back.green = (png_byte)png_ptr->background.green;
+ back.blue = (png_byte)png_ptr->background.blue;
+
+ for (i = 0; i < (int)png_ptr->num_trans; i++)
+ {
+ if (png_ptr->trans[i] == 0)
+ {
+ palette[i].red = back.red;
+ palette[i].green = back.green;
+ palette[i].blue = back.blue;
+ }
+ else if (png_ptr->trans[i] != 0xff)
+ {
+ png_composite(palette[i].red, png_ptr->palette[i].red,
+ png_ptr->trans[i], back.red);
+ png_composite(palette[i].green, png_ptr->palette[i].green,
+ png_ptr->trans[i], back.green);
+ png_composite(palette[i].blue, png_ptr->palette[i].blue,
+ png_ptr->trans[i], back.blue);
+ }
+ }
+ }
+ else /* assume grayscale palette (what else could it be?) */
+ {
+ int i;
+
+ for (i = 0; i < num_palette; i++)
+ {
+ if (i == (png_byte)png_ptr->trans_values.gray)
+ {
+ palette[i].red = (png_byte)png_ptr->background.red;
+ palette[i].green = (png_byte)png_ptr->background.green;
+ palette[i].blue = (png_byte)png_ptr->background.blue;
+ }
+ }
+ }
+ }
+#endif
+}
+#endif
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+/* Replace any alpha or transparency with the supplied background color.
+ * "background" is already in the screen gamma, while "background_1" is
+ * at a gamma of 1.0. Paletted files have already been taken care of.
+ */
+void /* PRIVATE */
+png_do_background(png_row_infop row_info, png_bytep row,
+ png_color_16p trans_values, png_color_16p background
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ , png_color_16p background_1,
+ png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
+ png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
+ png_uint_16pp gamma_16_to_1, int gamma_shift
+#endif
+ )
+{
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+ int shift;
+
+ png_debug(1, "in png_do_background\n");
+ if (background != NULL &&
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL &&
+#endif
+ (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||
+ (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values)))
+ {
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row;
+ shift = 7;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x01)
+ == trans_values->gray)
+ {
+ *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ if (!shift)
+ {
+ shift = 7;
+ sp++;
+ }
+ else
+ shift--;
+ }
+ break;
+ }
+ case 2:
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == trans_values->gray)
+ {
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ else
+ {
+ png_byte p = (png_byte)((*sp >> shift) & 0x03);
+ png_byte g = (png_byte)((gamma_table [p | (p << 2) |
+ (p << 4) | (p << 6)] >> 6) & 0x03);
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *sp |= (png_byte)(g << shift);
+ }
+ if (!shift)
+ {
+ shift = 6;
+ sp++;
+ }
+ else
+ shift -= 2;
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ shift = 6;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x03)
+ == trans_values->gray)
+ {
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ if (!shift)
+ {
+ shift = 6;
+ sp++;
+ }
+ else
+ shift -= 2;
+ }
+ }
+ break;
+ }
+ case 4:
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == trans_values->gray)
+ {
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ else
+ {
+ png_byte p = (png_byte)((*sp >> shift) & 0x0f);
+ png_byte g = (png_byte)((gamma_table[p |
+ (p << 4)] >> 4) & 0x0f);
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *sp |= (png_byte)(g << shift);
+ }
+ if (!shift)
+ {
+ shift = 4;
+ sp++;
+ }
+ else
+ shift -= 4;
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ shift = 4;
+ for (i = 0; i < row_width; i++)
+ {
+ if ((png_uint_16)((*sp >> shift) & 0x0f)
+ == trans_values->gray)
+ {
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
+ *sp |= (png_byte)(background->gray << shift);
+ }
+ if (!shift)
+ {
+ shift = 4;
+ sp++;
+ }
+ else
+ shift -= 4;
+ }
+ }
+ break;
+ }
+ case 8:
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == trans_values->gray)
+ {
+ *sp = (png_byte)background->gray;
+ }
+ else
+ {
+ *sp = gamma_table[*sp];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ if (*sp == trans_values->gray)
+ {
+ *sp = (png_byte)background->gray;
+ }
+ }
+ }
+ break;
+ }
+ case 16:
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ if (v == trans_values->gray)
+ {
+ /* background is already in screen gamma */
+ *sp = (png_byte)((background->gray >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->gray & 0xff);
+ }
+ else
+ {
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 2)
+ {
+ png_uint_16 v;
+
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ if (v == trans_values->gray)
+ {
+ *sp = (png_byte)((background->gray >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->gray & 0xff);
+ }
+ }
+ }
+ break;
+ }
+ }
+ break;
+ }
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_table != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == trans_values->red &&
+ *(sp + 1) == trans_values->green &&
+ *(sp + 2) == trans_values->blue)
+ {
+ *sp = (png_byte)background->red;
+ *(sp + 1) = (png_byte)background->green;
+ *(sp + 2) = (png_byte)background->blue;
+ }
+ else
+ {
+ *sp = gamma_table[*sp];
+ *(sp + 1) = gamma_table[*(sp + 1)];
+ *(sp + 2) = gamma_table[*(sp + 2)];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 3)
+ {
+ if (*sp == trans_values->red &&
+ *(sp + 1) == trans_values->green &&
+ *(sp + 2) == trans_values->blue)
+ {
+ *sp = (png_byte)background->red;
+ *(sp + 1) = (png_byte)background->green;
+ *(sp + 2) = (png_byte)background->blue;
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_16 != NULL)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+ png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
+ if (r == trans_values->red && g == trans_values->green &&
+ b == trans_values->blue)
+ {
+ /* background is already in screen gamma */
+ *sp = (png_byte)((background->red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->red & 0xff);
+ *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(background->green & 0xff);
+ *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ else
+ {
+ png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp += 6)
+ {
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1));
+ png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+ png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
+
+ if (r == trans_values->red && g == trans_values->green &&
+ b == trans_values->blue)
+ {
+ *sp = (png_byte)((background->red >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(background->red & 0xff);
+ *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(sp + 3) = (png_byte)(background->green & 0xff);
+ *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(sp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 2, dp++)
+ {
+ png_uint_16 a = *(sp + 1);
+
+ if (a == 0xff)
+ {
+ *dp = gamma_table[*sp];
+ }
+ else if (a == 0)
+ {
+ /* background is already in screen gamma */
+ *dp = (png_byte)background->gray;
+ }
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, background_1->gray);
+ *dp = gamma_from_1[w];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 2, dp++)
+ {
+ png_byte a = *(sp + 1);
+
+ if (a == 0xff)
+ {
+ *dp = *sp;
+ }
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ else if (a == 0)
+ {
+ *dp = (png_byte)background->gray;
+ }
+ else
+ {
+ png_composite(*dp, *sp, a, background_1->gray);
+ }
+#else
+ *dp = (png_byte)background->gray;
+#endif
+ }
+ }
+ }
+ else /* if (png_ptr->bit_depth == 16) */
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 2)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ }
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ else if (a == 0)
+#else
+ else
+#endif
+ {
+ /* background is already in screen gamma */
+ *dp = (png_byte)((background->gray >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->gray & 0xff);
+ }
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ else
+ {
+ png_uint_16 g, v, w;
+
+ g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(v, g, a, background_1->gray);
+ w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
+ *dp = (png_byte)((w >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(w & 0xff);
+ }
+#endif
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 2)
+ {
+ png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
+ if (a == (png_uint_16)0xffff)
+ {
+ png_memcpy(dp, sp, 2);
+ }
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ else if (a == 0)
+#else
+ else
+#endif
+ {
+ *dp = (png_byte)((background->gray >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->gray & 0xff);
+ }
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ else
+ {
+ png_uint_16 g, v;
+
+ g = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_composite_16(v, g, a, background_1->gray);
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ }
+#endif
+ }
+ }
+ }
+ break;
+ }
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
+ gamma_table != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 3)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0xff)
+ {
+ *dp = gamma_table[*sp];
+ *(dp + 1) = gamma_table[*(sp + 1)];
+ *(dp + 2) = gamma_table[*(sp + 2)];
+ }
+ else if (a == 0)
+ {
+ /* background is already in screen gamma */
+ *dp = (png_byte)background->red;
+ *(dp + 1) = (png_byte)background->green;
+ *(dp + 2) = (png_byte)background->blue;
+ }
+ else
+ {
+ png_byte v, w;
+
+ v = gamma_to_1[*sp];
+ png_composite(w, v, a, background_1->red);
+ *dp = gamma_from_1[w];
+ v = gamma_to_1[*(sp + 1)];
+ png_composite(w, v, a, background_1->green);
+ *(dp + 1) = gamma_from_1[w];
+ v = gamma_to_1[*(sp + 2)];
+ png_composite(w, v, a, background_1->blue);
+ *(dp + 2) = gamma_from_1[w];
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 4, dp += 3)
+ {
+ png_byte a = *(sp + 3);
+
+ if (a == 0xff)
+ {
+ *dp = *sp;
+ *(dp + 1) = *(sp + 1);
+ *(dp + 2) = *(sp + 2);
+ }
+ else if (a == 0)
+ {
+ *dp = (png_byte)background->red;
+ *(dp + 1) = (png_byte)background->green;
+ *(dp + 2) = (png_byte)background->blue;
+ }
+ else
+ {
+ png_composite(*dp, *sp, a, background->red);
+ png_composite(*(dp + 1), *(sp + 1), a,
+ background->green);
+ png_composite(*(dp + 2), *(sp + 2), a,
+ background->blue);
+ }
+ }
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
+ gamma_16_to_1 != NULL)
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 8, dp += 6)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+ if (a == (png_uint_16)0xffff)
+ {
+ png_uint_16 v;
+
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ *(dp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(v & 0xff);
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ *(dp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(v & 0xff);
+ }
+ else if (a == 0)
+ {
+ /* background is already in screen gamma */
+ *dp = (png_byte)((background->red >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->red & 0xff);
+ *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(background->green & 0xff);
+ *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ else
+ {
+ png_uint_16 v, w, x;
+
+ v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
+ png_composite_16(w, v, a, background_1->red);
+ x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+ *dp = (png_byte)((x >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(x & 0xff);
+ v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
+ png_composite_16(w, v, a, background_1->green);
+ x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
+ *(dp + 2) = (png_byte)((x >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(x & 0xff);
+ v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
+ png_composite_16(w, v, a, background_1->blue);
+ x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
+ *(dp + 4) = (png_byte)((x >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(x & 0xff);
+ }
+ }
+ }
+ else
+#endif
+ {
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++, sp += 8, dp += 6)
+ {
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))
+ << 8) + (png_uint_16)(*(sp + 7)));
+ if (a == (png_uint_16)0xffff)
+ {
+ png_memcpy(dp, sp, 6);
+ }
+ else if (a == 0)
+ {
+ *dp = (png_byte)((background->red >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(background->red & 0xff);
+ *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(background->green & 0xff);
+ *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(background->blue & 0xff);
+ }
+ else
+ {
+ png_uint_16 v;
+
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)
+ + *(sp + 3));
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)
+ + *(sp + 5));
+
+ png_composite_16(v, r, a, background->red);
+ *dp = (png_byte)((v >> 8) & 0xff);
+ *(dp + 1) = (png_byte)(v & 0xff);
+ png_composite_16(v, g, a, background->green);
+ *(dp + 2) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 3) = (png_byte)(v & 0xff);
+ png_composite_16(v, b, a, background->blue);
+ *(dp + 4) = (png_byte)((v >> 8) & 0xff);
+ *(dp + 5) = (png_byte)(v & 0xff);
+ }
+ }
+ }
+ }
+ break;
+ }
+ }
+
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
+ {
+ row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;
+ row_info->channels--;
+ row_info->pixel_depth = (png_byte)(row_info->channels *
+ row_info->bit_depth);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+/* Gamma correct the image, avoiding the alpha channel. Make sure
+ * you do this after you deal with the transparency issue on grayscale
+ * or RGB images. If your bit depth is 8, use gamma_table, if it
+ * is 16, use gamma_16_table and gamma_shift. Build these with
+ * build_gamma_table().
+ */
+void /* PRIVATE */
+png_do_gamma(png_row_infop row_info, png_bytep row,
+ png_bytep gamma_table, png_uint_16pp gamma_16_table,
+ int gamma_shift)
+{
+ png_bytep sp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_gamma\n");
+ if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL &&
+#endif
+ ((row_info->bit_depth <= 8 && gamma_table != NULL) ||
+ (row_info->bit_depth == 16 && gamma_16_table != NULL)))
+ {
+ switch (row_info->color_type)
+ {
+ case PNG_COLOR_TYPE_RGB:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v;
+
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+ case PNG_COLOR_TYPE_RGB_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ *sp = gamma_table[*sp];
+ sp++;
+ sp++;
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+ case PNG_COLOR_TYPE_GRAY_ALPHA:
+ {
+ if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp += 2;
+ }
+ }
+ else /* if (row_info->bit_depth == 16) */
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 4;
+ }
+ }
+ break;
+ }
+ case PNG_COLOR_TYPE_GRAY:
+ {
+ if (row_info->bit_depth == 2)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 4)
+ {
+ int a = *sp & 0xc0;
+ int b = *sp & 0x30;
+ int c = *sp & 0x0c;
+ int d = *sp & 0x03;
+
+ *sp = (png_byte)(
+ ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
+ ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
+ ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
+ ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
+ sp++;
+ }
+ }
+ if (row_info->bit_depth == 4)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i += 2)
+ {
+ int msb = *sp & 0xf0;
+ int lsb = *sp & 0x0f;
+
+ *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
+ | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
+ sp++;
+ }
+ }
+ else if (row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ *sp = gamma_table[*sp];
+ sp++;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];
+ *sp = (png_byte)((v >> 8) & 0xff);
+ *(sp + 1) = (png_byte)(v & 0xff);
+ sp += 2;
+ }
+ }
+ break;
+ }
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_EXPAND_SUPPORTED)
+/* Expands a palette row to an RGB or RGBA row depending
+ * upon whether you supply trans and num_trans.
+ */
+void /* PRIVATE */
+png_do_expand_palette(png_row_infop row_info, png_bytep row,
+ png_colorp palette, png_bytep trans, int num_trans)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand_palette\n");
+ if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL &&
+#endif
+ row_info->color_type == PNG_COLOR_TYPE_PALETTE)
+ {
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 3);
+ dp = row + (png_size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 1;
+ else
+ *dp = 0;
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+ case 2:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 2);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)value;
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+ case 4:
+ {
+ sp = row + (png_size_t)((row_width - 1) >> 1);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((row_width & 0x01) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)value;
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 4;
+
+ dp--;
+ }
+ break;
+ }
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+ switch (row_info->bit_depth)
+ {
+ case 8:
+ {
+ if (trans != NULL)
+ {
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width << 2) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ if ((int)(*sp) >= num_trans)
+ *dp-- = 0xff;
+ else
+ *dp-- = trans[*sp];
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 32;
+ row_info->rowbytes = row_width * 4;
+ row_info->color_type = 6;
+ row_info->channels = 4;
+ }
+ else
+ {
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width * 3) - 1;
+
+ for (i = 0; i < row_width; i++)
+ {
+ *dp-- = palette[*sp].blue;
+ *dp-- = palette[*sp].green;
+ *dp-- = palette[*sp].red;
+ sp--;
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 24;
+ row_info->rowbytes = row_width * 3;
+ row_info->color_type = 2;
+ row_info->channels = 3;
+ }
+ break;
+ }
+ }
+ }
+}
+
+/* If the bit depth < 8, it is expanded to 8. Also, if the already
+ * expanded transparency value is supplied, an alpha channel is built.
+ */
+void /* PRIVATE */
+png_do_expand(png_row_infop row_info, png_bytep row,
+ png_color_16p trans_value)
+{
+ int shift, value;
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_expand\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ if (row != NULL && row_info != NULL)
+#endif
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
+ {
+ png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);
+
+ if (row_info->bit_depth < 8)
+ {
+ switch (row_info->bit_depth)
+ {
+ case 1:
+ {
+ gray = (png_uint_16)((gray&0x01)*0xff);
+ sp = row + (png_size_t)((row_width - 1) >> 3);
+ dp = row + (png_size_t)row_width - 1;
+ shift = 7 - (int)((row_width + 7) & 0x07);
+ for (i = 0; i < row_width; i++)
+ {
+ if ((*sp >> shift) & 0x01)
+ *dp = 0xff;
+ else
+ *dp = 0;
+ if (shift == 7)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift++;
+
+ dp--;
+ }
+ break;
+ }
+ case 2:
+ {
+ gray = (png_uint_16)((gray&0x03)*0x55);
+ sp = row + (png_size_t)((row_width - 1) >> 2);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x03;
+ *dp = (png_byte)(value | (value << 2) | (value << 4) |
+ (value << 6));
+ if (shift == 6)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift += 2;
+
+ dp--;
+ }
+ break;
+ }
+ case 4:
+ {
+ gray = (png_uint_16)((gray&0x0f)*0x11);
+ sp = row + (png_size_t)((row_width - 1) >> 1);
+ dp = row + (png_size_t)row_width - 1;
+ shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
+ for (i = 0; i < row_width; i++)
+ {
+ value = (*sp >> shift) & 0x0f;
+ *dp = (png_byte)(value | (value << 4));
+ if (shift == 4)
+ {
+ shift = 0;
+ sp--;
+ }
+ else
+ shift = 4;
+
+ dp--;
+ }
+ break;
+ }
+ }
+ row_info->bit_depth = 8;
+ row_info->pixel_depth = 8;
+ row_info->rowbytes = row_width;
+ }
+
+ if (trans_value != NULL)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ gray = gray & 0xff;
+ sp = row + (png_size_t)row_width - 1;
+ dp = row + (png_size_t)(row_width << 1) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*sp == gray)
+ *dp-- = 0;
+ else
+ *dp-- = 0xff;
+ *dp-- = *sp--;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_byte gray_high = (gray >> 8) & 0xff;
+ png_byte gray_low = gray & 0xff;
+ sp = row + row_info->rowbytes - 1;
+ dp = row + (row_info->rowbytes << 1) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp-1) == gray_high && *(sp) == gray_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+ row_info->channels = 2;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
+ row_width);
+ }
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)
+ {
+ if (row_info->bit_depth == 8)
+ {
+ png_byte red = trans_value->red & 0xff;
+ png_byte green = trans_value->green & 0xff;
+ png_byte blue = trans_value->blue & 0xff;
+ sp = row + (png_size_t)row_info->rowbytes - 1;
+ dp = row + (png_size_t)(row_width << 2) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
+ *dp-- = 0;
+ else
+ *dp-- = 0xff;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_byte red_high = (trans_value->red >> 8) & 0xff;
+ png_byte green_high = (trans_value->green >> 8) & 0xff;
+ png_byte blue_high = (trans_value->blue >> 8) & 0xff;
+ png_byte red_low = trans_value->red & 0xff;
+ png_byte green_low = trans_value->green & 0xff;
+ png_byte blue_low = trans_value->blue & 0xff;
+ sp = row + row_info->rowbytes - 1;
+ dp = row + (png_size_t)(row_width << 3) - 1;
+ for (i = 0; i < row_width; i++)
+ {
+ if (*(sp - 5) == red_high &&
+ *(sp - 4) == red_low &&
+ *(sp - 3) == green_high &&
+ *(sp - 2) == green_low &&
+ *(sp - 1) == blue_high &&
+ *(sp ) == blue_low)
+ {
+ *dp-- = 0;
+ *dp-- = 0;
+ }
+ else
+ {
+ *dp-- = 0xff;
+ *dp-- = 0xff;
+ }
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ *dp-- = *sp--;
+ }
+ }
+ row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+ row_info->channels = 4;
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+ }
+ }
+}
+#endif
+
+#if defined(PNG_READ_DITHER_SUPPORTED)
+void /* PRIVATE */
+png_do_dither(png_row_infop row_info, png_bytep row,
+ png_bytep palette_lookup, png_bytep dither_lookup)
+{
+ png_bytep sp, dp;
+ png_uint_32 i;
+ png_uint_32 row_width=row_info->width;
+
+ png_debug(1, "in png_do_dither\n");
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ if (row != NULL && row_info != NULL)
+#endif
+ {
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
+ palette_lookup && row_info->bit_depth == 8)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+
+ /* this looks real messy, but the compiler will reduce
+ it down to a reasonable formula. For example, with
+ 5 bits per color, we get:
+ p = (((r >> 3) & 0x1f) << 10) |
+ (((g >> 3) & 0x1f) << 5) |
+ ((b >> 3) & 0x1f);
+ */
+ p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
+ ((1 << PNG_DITHER_RED_BITS) - 1)) <<
+ (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
+ (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
+ ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
+ (PNG_DITHER_BLUE_BITS)) |
+ ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
+ ((1 << PNG_DITHER_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&
+ palette_lookup != NULL && row_info->bit_depth == 8)
+ {
+ int r, g, b, p;
+ sp = row;
+ dp = row;
+ for (i = 0; i < row_width; i++)
+ {
+ r = *sp++;
+ g = *sp++;
+ b = *sp++;
+ sp++;
+
+ p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
+ ((1 << PNG_DITHER_RED_BITS) - 1)) <<
+ (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
+ (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
+ ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
+ (PNG_DITHER_BLUE_BITS)) |
+ ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
+ ((1 << PNG_DITHER_BLUE_BITS) - 1));
+
+ *dp++ = palette_lookup[p];
+ }
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;
+ row_info->channels = 1;
+ row_info->pixel_depth = row_info->bit_depth;
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,row_width);
+ }
+ else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
+ dither_lookup && row_info->bit_depth == 8)
+ {
+ sp = row;
+ for (i = 0; i < row_width; i++, sp++)
+ {
+ *sp = dither_lookup[*sp];
+ }
+ }
+ }
+}
+#endif
+
+#ifdef PNG_FLOATING_POINT_SUPPORTED
+#if defined(PNG_READ_GAMMA_SUPPORTED)
+static PNG_CONST int png_gamma_shift[] =
+ {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
+
+/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
+ * tables, we don't make a full table if we are reducing to 8-bit in
+ * the future. Note also how the gamma_16 tables are segmented so that
+ * we don't need to allocate > 64K chunks for a full 16-bit table.
+ */
+void /* PRIVATE */
+png_build_gamma_table(png_structp png_ptr)
+{
+ png_debug(1, "in png_build_gamma_table\n");
+
+ if (png_ptr->bit_depth <= 8)
+ {
+ int i;
+ double g;
+
+ if (png_ptr->screen_gamma > .000001)
+ g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+ else
+ g = 1.0;
+
+ png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)256);
+
+ for (i = 0; i < 256; i++)
+ {
+ png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,
+ g) * 255.0 + .5);
+ }
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))
+ {
+
+ g = 1.0 / (png_ptr->gamma);
+
+ png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)256);
+
+ for (i = 0; i < 256; i++)
+ {
+ png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,
+ g) * 255.0 + .5);
+ }
+
+
+ png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)256);
+
+ if(png_ptr->screen_gamma > 0.000001)
+ g = 1.0 / png_ptr->screen_gamma;
+ else
+ g = png_ptr->gamma; /* probably doing rgb_to_gray */
+
+ for (i = 0; i < 256; i++)
+ {
+ png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,
+ g) * 255.0 + .5);
+
+ }
+ }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
+ }
+ else
+ {
+ double g;
+ int i, j, shift, num;
+ int sig_bit;
+ png_uint_32 ig;
+
+ if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
+ {
+ sig_bit = (int)png_ptr->sig_bit.red;
+ if ((int)png_ptr->sig_bit.green > sig_bit)
+ sig_bit = png_ptr->sig_bit.green;
+ if ((int)png_ptr->sig_bit.blue > sig_bit)
+ sig_bit = png_ptr->sig_bit.blue;
+ }
+ else
+ {
+ sig_bit = (int)png_ptr->sig_bit.gray;
+ }
+
+ if (sig_bit > 0)
+ shift = 16 - sig_bit;
+ else
+ shift = 0;
+
+ if (png_ptr->transformations & PNG_16_TO_8)
+ {
+ if (shift < (16 - PNG_MAX_GAMMA_8))
+ shift = (16 - PNG_MAX_GAMMA_8);
+ }
+
+ if (shift > 8)
+ shift = 8;
+ if (shift < 0)
+ shift = 0;
+
+ png_ptr->gamma_shift = (png_byte)shift;
+
+ num = (1 << (8 - shift));
+
+ if (png_ptr->screen_gamma > .000001)
+ g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+ else
+ g = 1.0;
+
+ png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
+ (png_uint_32)(num * png_sizeof (png_uint_16p)));
+
+ if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
+ {
+ double fin, fout;
+ png_uint_32 last, max;
+
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof (png_uint_16)));
+ }
+
+ g = 1.0 / g;
+ last = 0;
+ for (i = 0; i < 256; i++)
+ {
+ fout = ((double)i + 0.5) / 256.0;
+ fin = pow(fout, g);
+ max = (png_uint_32)(fin * (double)((png_uint_32)num << 8));
+ while (last <= max)
+ {
+ png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
+ [(int)(last >> (8 - shift))] = (png_uint_16)(
+ (png_uint_16)i | ((png_uint_16)i << 8));
+ last++;
+ }
+ }
+ while (last < ((png_uint_32)num << 8))
+ {
+ png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]
+ [(int)(last >> (8 - shift))] = (png_uint_16)65535L;
+ last++;
+ }
+ }
+ else
+ {
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof (png_uint_16)));
+
+ ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
+ for (j = 0; j < 256; j++)
+ {
+ png_ptr->gamma_16_table[i][j] =
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
+ 65535.0, g) * 65535.0 + .5);
+ }
+ }
+ }
+
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+ if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))
+ {
+
+ g = 1.0 / (png_ptr->gamma);
+
+ png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
+ (png_uint_32)(num * png_sizeof (png_uint_16p )));
+
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof (png_uint_16)));
+
+ ig = (((png_uint_32)i *
+ (png_uint_32)png_gamma_shift[shift]) >> 4);
+ for (j = 0; j < 256; j++)
+ {
+ png_ptr->gamma_16_to_1[i][j] =
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
+ 65535.0, g) * 65535.0 + .5);
+ }
+ }
+
+ if(png_ptr->screen_gamma > 0.000001)
+ g = 1.0 / png_ptr->screen_gamma;
+ else
+ g = png_ptr->gamma; /* probably doing rgb_to_gray */
+
+ png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
+ (png_uint_32)(num * png_sizeof (png_uint_16p)));
+
+ for (i = 0; i < num; i++)
+ {
+ png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,
+ (png_uint_32)(256 * png_sizeof (png_uint_16)));
+
+ ig = (((png_uint_32)i *
+ (png_uint_32)png_gamma_shift[shift]) >> 4);
+ for (j = 0; j < 256; j++)
+ {
+ png_ptr->gamma_16_from_1[i][j] =
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /
+ 65535.0, g) * 65535.0 + .5);
+ }
+ }
+ }
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */
+ }
+}
+#endif
+/* To do: install integer version of png_build_gamma_table here */
+#endif
+
+#if defined(PNG_MNG_FEATURES_SUPPORTED)
+/* undoes intrapixel differencing */
+void /* PRIVATE */
+png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
+{
+ png_debug(1, "in png_do_read_intrapixel\n");
+ if (
+#if defined(PNG_USELESS_TESTS_SUPPORTED)
+ row != NULL && row_info != NULL &&
+#endif
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))
+ {
+ int bytes_per_pixel;
+ png_uint_32 row_width = row_info->width;
+ if (row_info->bit_depth == 8)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 3;
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 4;
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff);
+ *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff);
+ }
+ }
+ else if (row_info->bit_depth == 16)
+ {
+ png_bytep rp;
+ png_uint_32 i;
+
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)
+ bytes_per_pixel = 6;
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
+ bytes_per_pixel = 8;
+ else
+ return;
+
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
+ {
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp+1);
+ png_uint_32 s1 = (*(rp+2) << 8) | *(rp+3);
+ png_uint_32 s2 = (*(rp+4) << 8) | *(rp+5);
+ png_uint_32 red = (png_uint_32)((s0+s1+65536L) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2+s1+65536L) & 0xffffL);
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp+1) = (png_byte)(red & 0xff);
+ *(rp+4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp+5) = (png_byte)(blue & 0xff);
+ }
+ }
+ }
+}
+#endif /* PNG_MNG_FEATURES_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED */
projects / opencv / blobdiff