--- /dev/null
+\r
+/* pngrtran.c - transforms the data in a row for PNG readers\r
+ *\r
+ * Last changed in libpng 1.2.30 [August 15, 2008]\r
+ * For conditions of distribution and use, see copyright notice in png.h\r
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson\r
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)\r
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)\r
+ *\r
+ * This file contains functions optionally called by an application\r
+ * in order to tell libpng how to handle data when reading a PNG.\r
+ * Transformations that are used in both reading and writing are\r
+ * in pngtrans.c.\r
+ */\r
+\r
+#define PNG_INTERNAL\r
+#include "png.h"\r
+#if defined(PNG_READ_SUPPORTED)\r
+\r
+/* Set the action on getting a CRC error for an ancillary or critical chunk. */\r
+void PNGAPI\r
+png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)\r
+{\r
+ png_debug(1, "in png_set_crc_action\n");\r
+ /* Tell libpng how we react to CRC errors in critical chunks */\r
+ if (png_ptr == NULL) return;\r
+ switch (crit_action)\r
+ {\r
+ case PNG_CRC_NO_CHANGE: /* leave setting as is */\r
+ break;\r
+ case PNG_CRC_WARN_USE: /* warn/use data */\r
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;\r
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;\r
+ break;\r
+ case PNG_CRC_QUIET_USE: /* quiet/use data */\r
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;\r
+ png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |\r
+ PNG_FLAG_CRC_CRITICAL_IGNORE;\r
+ break;\r
+ case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */\r
+ png_warning(png_ptr,\r
+ "Can't discard critical data on CRC error.");\r
+ case PNG_CRC_ERROR_QUIT: /* error/quit */\r
+ case PNG_CRC_DEFAULT:\r
+ default:\r
+ png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;\r
+ break;\r
+ }\r
+\r
+ switch (ancil_action)\r
+ {\r
+ case PNG_CRC_NO_CHANGE: /* leave setting as is */\r
+ break;\r
+ case PNG_CRC_WARN_USE: /* warn/use data */\r
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;\r
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;\r
+ break;\r
+ case PNG_CRC_QUIET_USE: /* quiet/use data */\r
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;\r
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |\r
+ PNG_FLAG_CRC_ANCILLARY_NOWARN;\r
+ break;\r
+ case PNG_CRC_ERROR_QUIT: /* error/quit */\r
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;\r
+ png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;\r
+ break;\r
+ case PNG_CRC_WARN_DISCARD: /* warn/discard data */\r
+ case PNG_CRC_DEFAULT:\r
+ default:\r
+ png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;\r
+ break;\r
+ }\r
+}\r
+\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \\r
+ defined(PNG_FLOATING_POINT_SUPPORTED)\r
+/* handle alpha and tRNS via a background color */\r
+void PNGAPI\r
+png_set_background(png_structp png_ptr,\r
+ png_color_16p background_color, int background_gamma_code,\r
+ int need_expand, double background_gamma)\r
+{\r
+ png_debug(1, "in png_set_background\n");\r
+ if (png_ptr == NULL) return;\r
+ if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)\r
+ {\r
+ png_warning(png_ptr, "Application must supply a known background gamma");\r
+ return;\r
+ }\r
+\r
+ png_ptr->transformations |= PNG_BACKGROUND;\r
+ png_memcpy(&(png_ptr->background), background_color,\r
+ png_sizeof(png_color_16));\r
+ png_ptr->background_gamma = (float)background_gamma;\r
+ png_ptr->background_gamma_type = (png_byte)(background_gamma_code);\r
+ png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_16_TO_8_SUPPORTED)\r
+/* strip 16 bit depth files to 8 bit depth */\r
+void PNGAPI\r
+png_set_strip_16(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_strip_16\n");\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->transformations |= PNG_16_TO_8;\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)\r
+void PNGAPI\r
+png_set_strip_alpha(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_strip_alpha\n");\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_DITHER_SUPPORTED)\r
+/* Dither file to 8 bit. Supply a palette, the current number\r
+ * of elements in the palette, the maximum number of elements\r
+ * allowed, and a histogram if possible. If the current number\r
+ * of colors is greater then the maximum number, the palette will be\r
+ * modified to fit in the maximum number. "full_dither" indicates\r
+ * whether we need a dithering cube set up for RGB images, or if we\r
+ * simply are reducing the number of colors in a paletted image.\r
+ */\r
+\r
+typedef struct png_dsort_struct\r
+{\r
+ struct png_dsort_struct FAR * next;\r
+ png_byte left;\r
+ png_byte right;\r
+} png_dsort;\r
+typedef png_dsort FAR * png_dsortp;\r
+typedef png_dsort FAR * FAR * png_dsortpp;\r
+\r
+void PNGAPI\r
+png_set_dither(png_structp png_ptr, png_colorp palette,\r
+ int num_palette, int maximum_colors, png_uint_16p histogram,\r
+ int full_dither)\r
+{\r
+ png_debug(1, "in png_set_dither\n");\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->transformations |= PNG_DITHER;\r
+\r
+ if (!full_dither)\r
+ {\r
+ int i;\r
+\r
+ png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));\r
+ for (i = 0; i < num_palette; i++)\r
+ png_ptr->dither_index[i] = (png_byte)i;\r
+ }\r
+\r
+ if (num_palette > maximum_colors)\r
+ {\r
+ if (histogram != NULL)\r
+ {\r
+ /* This is easy enough, just throw out the least used colors.\r
+ Perhaps not the best solution, but good enough. */\r
+\r
+ int i;\r
+\r
+ /* initialize an array to sort colors */\r
+ png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));\r
+\r
+ /* initialize the dither_sort array */\r
+ for (i = 0; i < num_palette; i++)\r
+ png_ptr->dither_sort[i] = (png_byte)i;\r
+\r
+ /* Find the least used palette entries by starting a\r
+ bubble sort, and running it until we have sorted\r
+ out enough colors. Note that we don't care about\r
+ sorting all the colors, just finding which are\r
+ least used. */\r
+\r
+ for (i = num_palette - 1; i >= maximum_colors; i--)\r
+ {\r
+ int done; /* to stop early if the list is pre-sorted */\r
+ int j;\r
+\r
+ done = 1;\r
+ for (j = 0; j < i; j++)\r
+ {\r
+ if (histogram[png_ptr->dither_sort[j]]\r
+ < histogram[png_ptr->dither_sort[j + 1]])\r
+ {\r
+ png_byte t;\r
+\r
+ t = png_ptr->dither_sort[j];\r
+ png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];\r
+ png_ptr->dither_sort[j + 1] = t;\r
+ done = 0;\r
+ }\r
+ }\r
+ if (done)\r
+ break;\r
+ }\r
+\r
+ /* swap the palette around, and set up a table, if necessary */\r
+ if (full_dither)\r
+ {\r
+ int j = num_palette;\r
+\r
+ /* put all the useful colors within the max, but don't\r
+ move the others */\r
+ for (i = 0; i < maximum_colors; i++)\r
+ {\r
+ if ((int)png_ptr->dither_sort[i] >= maximum_colors)\r
+ {\r
+ do\r
+ j--;\r
+ while ((int)png_ptr->dither_sort[j] >= maximum_colors);\r
+ palette[i] = palette[j];\r
+ }\r
+ }\r
+ }\r
+ else\r
+ {\r
+ int j = num_palette;\r
+\r
+ /* move all the used colors inside the max limit, and\r
+ develop a translation table */\r
+ for (i = 0; i < maximum_colors; i++)\r
+ {\r
+ /* only move the colors we need to */\r
+ if ((int)png_ptr->dither_sort[i] >= maximum_colors)\r
+ {\r
+ png_color tmp_color;\r
+\r
+ do\r
+ j--;\r
+ while ((int)png_ptr->dither_sort[j] >= maximum_colors);\r
+\r
+ tmp_color = palette[j];\r
+ palette[j] = palette[i];\r
+ palette[i] = tmp_color;\r
+ /* indicate where the color went */\r
+ png_ptr->dither_index[j] = (png_byte)i;\r
+ png_ptr->dither_index[i] = (png_byte)j;\r
+ }\r
+ }\r
+\r
+ /* find closest color for those colors we are not using */\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ if ((int)png_ptr->dither_index[i] >= maximum_colors)\r
+ {\r
+ int min_d, k, min_k, d_index;\r
+\r
+ /* find the closest color to one we threw out */\r
+ d_index = png_ptr->dither_index[i];\r
+ min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);\r
+ for (k = 1, min_k = 0; k < maximum_colors; k++)\r
+ {\r
+ int d;\r
+\r
+ d = PNG_COLOR_DIST(palette[d_index], palette[k]);\r
+\r
+ if (d < min_d)\r
+ {\r
+ min_d = d;\r
+ min_k = k;\r
+ }\r
+ }\r
+ /* point to closest color */\r
+ png_ptr->dither_index[i] = (png_byte)min_k;\r
+ }\r
+ }\r
+ }\r
+ png_free(png_ptr, png_ptr->dither_sort);\r
+ png_ptr->dither_sort = NULL;\r
+ }\r
+ else\r
+ {\r
+ /* This is much harder to do simply (and quickly). Perhaps\r
+ we need to go through a median cut routine, but those\r
+ don't always behave themselves with only a few colors\r
+ as input. So we will just find the closest two colors,\r
+ and throw out one of them (chosen somewhat randomly).\r
+ [We don't understand this at all, so if someone wants to\r
+ work on improving it, be our guest - AED, GRP]\r
+ */\r
+ int i;\r
+ int max_d;\r
+ int num_new_palette;\r
+ png_dsortp t;\r
+ png_dsortpp hash;\r
+\r
+ t = NULL;\r
+\r
+ /* initialize palette index arrays */\r
+ png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));\r
+ png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)(num_palette * png_sizeof(png_byte)));\r
+\r
+ /* initialize the sort array */\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ png_ptr->index_to_palette[i] = (png_byte)i;\r
+ png_ptr->palette_to_index[i] = (png_byte)i;\r
+ }\r
+\r
+ hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *\r
+ png_sizeof(png_dsortp)));\r
+ for (i = 0; i < 769; i++)\r
+ hash[i] = NULL;\r
+/* png_memset(hash, 0, 769 * png_sizeof(png_dsortp)); */\r
+\r
+ num_new_palette = num_palette;\r
+\r
+ /* initial wild guess at how far apart the farthest pixel\r
+ pair we will be eliminating will be. Larger\r
+ numbers mean more areas will be allocated, Smaller\r
+ numbers run the risk of not saving enough data, and\r
+ having to do this all over again.\r
+\r
+ I have not done extensive checking on this number.\r
+ */\r
+ max_d = 96;\r
+\r
+ while (num_new_palette > maximum_colors)\r
+ {\r
+ for (i = 0; i < num_new_palette - 1; i++)\r
+ {\r
+ int j;\r
+\r
+ for (j = i + 1; j < num_new_palette; j++)\r
+ {\r
+ int d;\r
+\r
+ d = PNG_COLOR_DIST(palette[i], palette[j]);\r
+\r
+ if (d <= max_d)\r
+ {\r
+\r
+ t = (png_dsortp)png_malloc_warn(png_ptr,\r
+ (png_uint_32)(png_sizeof(png_dsort)));\r
+ if (t == NULL)\r
+ break;\r
+ t->next = hash[d];\r
+ t->left = (png_byte)i;\r
+ t->right = (png_byte)j;\r
+ hash[d] = t;\r
+ }\r
+ }\r
+ if (t == NULL)\r
+ break;\r
+ }\r
+\r
+ if (t != NULL)\r
+ for (i = 0; i <= max_d; i++)\r
+ {\r
+ if (hash[i] != NULL)\r
+ {\r
+ png_dsortp p;\r
+\r
+ for (p = hash[i]; p; p = p->next)\r
+ {\r
+ if ((int)png_ptr->index_to_palette[p->left]\r
+ < num_new_palette &&\r
+ (int)png_ptr->index_to_palette[p->right]\r
+ < num_new_palette)\r
+ {\r
+ int j, next_j;\r
+\r
+ if (num_new_palette & 0x01)\r
+ {\r
+ j = p->left;\r
+ next_j = p->right;\r
+ }\r
+ else\r
+ {\r
+ j = p->right;\r
+ next_j = p->left;\r
+ }\r
+\r
+ num_new_palette--;\r
+ palette[png_ptr->index_to_palette[j]]\r
+ = palette[num_new_palette];\r
+ if (!full_dither)\r
+ {\r
+ int k;\r
+\r
+ for (k = 0; k < num_palette; k++)\r
+ {\r
+ if (png_ptr->dither_index[k] ==\r
+ png_ptr->index_to_palette[j])\r
+ png_ptr->dither_index[k] =\r
+ png_ptr->index_to_palette[next_j];\r
+ if ((int)png_ptr->dither_index[k] ==\r
+ num_new_palette)\r
+ png_ptr->dither_index[k] =\r
+ png_ptr->index_to_palette[j];\r
+ }\r
+ }\r
+\r
+ png_ptr->index_to_palette[png_ptr->palette_to_index\r
+ [num_new_palette]] = png_ptr->index_to_palette[j];\r
+ png_ptr->palette_to_index[png_ptr->index_to_palette[j]]\r
+ = png_ptr->palette_to_index[num_new_palette];\r
+\r
+ png_ptr->index_to_palette[j] = (png_byte)num_new_palette;\r
+ png_ptr->palette_to_index[num_new_palette] = (png_byte)j;\r
+ }\r
+ if (num_new_palette <= maximum_colors)\r
+ break;\r
+ }\r
+ if (num_new_palette <= maximum_colors)\r
+ break;\r
+ }\r
+ }\r
+\r
+ for (i = 0; i < 769; i++)\r
+ {\r
+ if (hash[i] != NULL)\r
+ {\r
+ png_dsortp p = hash[i];\r
+ while (p)\r
+ {\r
+ t = p->next;\r
+ png_free(png_ptr, p);\r
+ p = t;\r
+ }\r
+ }\r
+ hash[i] = 0;\r
+ }\r
+ max_d += 96;\r
+ }\r
+ png_free(png_ptr, hash);\r
+ png_free(png_ptr, png_ptr->palette_to_index);\r
+ png_free(png_ptr, png_ptr->index_to_palette);\r
+ png_ptr->palette_to_index = NULL;\r
+ png_ptr->index_to_palette = NULL;\r
+ }\r
+ num_palette = maximum_colors;\r
+ }\r
+ if (png_ptr->palette == NULL)\r
+ {\r
+ png_ptr->palette = palette;\r
+ }\r
+ png_ptr->num_palette = (png_uint_16)num_palette;\r
+\r
+ if (full_dither)\r
+ {\r
+ int i;\r
+ png_bytep distance;\r
+ int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +\r
+ PNG_DITHER_BLUE_BITS;\r
+ int num_red = (1 << PNG_DITHER_RED_BITS);\r
+ int num_green = (1 << PNG_DITHER_GREEN_BITS);\r
+ int num_blue = (1 << PNG_DITHER_BLUE_BITS);\r
+ png_size_t num_entries = ((png_size_t)1 << total_bits);\r
+\r
+ png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr,\r
+ (png_uint_32)(num_entries * png_sizeof(png_byte)));\r
+\r
+ png_memset(png_ptr->palette_lookup, 0, num_entries *\r
+ png_sizeof(png_byte));\r
+\r
+ distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *\r
+ png_sizeof(png_byte)));\r
+\r
+ png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));\r
+\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ int ir, ig, ib;\r
+ int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));\r
+ int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));\r
+ int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));\r
+\r
+ for (ir = 0; ir < num_red; ir++)\r
+ {\r
+ /* int dr = abs(ir - r); */\r
+ int dr = ((ir > r) ? ir - r : r - ir);\r
+ int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS));\r
+\r
+ for (ig = 0; ig < num_green; ig++)\r
+ {\r
+ /* int dg = abs(ig - g); */\r
+ int dg = ((ig > g) ? ig - g : g - ig);\r
+ int dt = dr + dg;\r
+ int dm = ((dr > dg) ? dr : dg);\r
+ int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS);\r
+\r
+ for (ib = 0; ib < num_blue; ib++)\r
+ {\r
+ int d_index = index_g | ib;\r
+ /* int db = abs(ib - b); */\r
+ int db = ((ib > b) ? ib - b : b - ib);\r
+ int dmax = ((dm > db) ? dm : db);\r
+ int d = dmax + dt + db;\r
+\r
+ if (d < (int)distance[d_index])\r
+ {\r
+ distance[d_index] = (png_byte)d;\r
+ png_ptr->palette_lookup[d_index] = (png_byte)i;\r
+ }\r
+ }\r
+ }\r
+ }\r
+ }\r
+\r
+ png_free(png_ptr, distance);\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)\r
+/* Transform the image from the file_gamma to the screen_gamma. We\r
+ * only do transformations on images where the file_gamma and screen_gamma\r
+ * are not close reciprocals, otherwise it slows things down slightly, and\r
+ * also needlessly introduces small errors.\r
+ *\r
+ * We will turn off gamma transformation later if no semitransparent entries\r
+ * are present in the tRNS array for palette images. We can't do it here\r
+ * because we don't necessarily have the tRNS chunk yet.\r
+ */\r
+void PNGAPI\r
+png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)\r
+{\r
+ png_debug(1, "in png_set_gamma\n");\r
+ if (png_ptr == NULL) return;\r
+ if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||\r
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||\r
+ (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))\r
+ png_ptr->transformations |= PNG_GAMMA;\r
+ png_ptr->gamma = (float)file_gamma;\r
+ png_ptr->screen_gamma = (float)scrn_gamma;\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_EXPAND_SUPPORTED)\r
+/* Expand paletted images to RGB, expand grayscale images of\r
+ * less than 8-bit depth to 8-bit depth, and expand tRNS chunks\r
+ * to alpha channels.\r
+ */\r
+void PNGAPI\r
+png_set_expand(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_expand\n");\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);\r
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;\r
+}\r
+\r
+/* GRR 19990627: the following three functions currently are identical\r
+ * to png_set_expand(). However, it is entirely reasonable that someone\r
+ * might wish to expand an indexed image to RGB but *not* expand a single,\r
+ * fully transparent palette entry to a full alpha channel--perhaps instead\r
+ * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace\r
+ * the transparent color with a particular RGB value, or drop tRNS entirely.\r
+ * IOW, a future version of the library may make the transformations flag\r
+ * a bit more fine-grained, with separate bits for each of these three\r
+ * functions.\r
+ *\r
+ * More to the point, these functions make it obvious what libpng will be\r
+ * doing, whereas "expand" can (and does) mean any number of things.\r
+ *\r
+ * GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified\r
+ * to expand only the sample depth but not to expand the tRNS to alpha.\r
+ */\r
+\r
+/* Expand paletted images to RGB. */\r
+void PNGAPI\r
+png_set_palette_to_rgb(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_palette_to_rgb\n");\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);\r
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;\r
+}\r
+\r
+#if !defined(PNG_1_0_X)\r
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */\r
+void PNGAPI\r
+png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_expand_gray_1_2_4_to_8\n");\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->transformations |= PNG_EXPAND;\r
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;\r
+}\r
+#endif\r
+\r
+#if defined(PNG_1_0_X) || defined(PNG_1_2_X)\r
+/* Expand grayscale images of less than 8-bit depth to 8 bits. */\r
+/* Deprecated as of libpng-1.2.9 */\r
+void PNGAPI\r
+png_set_gray_1_2_4_to_8(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_gray_1_2_4_to_8\n");\r
+ if (png_ptr == NULL) return;\r
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);\r
+}\r
+#endif\r
+\r
+\r
+/* Expand tRNS chunks to alpha channels. */\r
+void PNGAPI\r
+png_set_tRNS_to_alpha(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_tRNS_to_alpha\n");\r
+ png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);\r
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;\r
+}\r
+#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */\r
+\r
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)\r
+void PNGAPI\r
+png_set_gray_to_rgb(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_set_gray_to_rgb\n");\r
+ png_ptr->transformations |= PNG_GRAY_TO_RGB;\r
+ png_ptr->flags &= ~PNG_FLAG_ROW_INIT;\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)\r
+#if defined(PNG_FLOATING_POINT_SUPPORTED)\r
+/* Convert a RGB image to a grayscale of the same width. This allows us,\r
+ * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.\r
+ */\r
+\r
+void PNGAPI\r
+png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,\r
+ double green)\r
+{\r
+ int red_fixed = (int)((float)red*100000.0 + 0.5);\r
+ int green_fixed = (int)((float)green*100000.0 + 0.5);\r
+ if (png_ptr == NULL) return;\r
+ png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);\r
+}\r
+#endif\r
+\r
+void PNGAPI\r
+png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,\r
+ png_fixed_point red, png_fixed_point green)\r
+{\r
+ png_debug(1, "in png_set_rgb_to_gray\n");\r
+ if (png_ptr == NULL) return;\r
+ switch(error_action)\r
+ {\r
+ case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;\r
+ break;\r
+ case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;\r
+ break;\r
+ case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;\r
+ }\r
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)\r
+#if defined(PNG_READ_EXPAND_SUPPORTED)\r
+ png_ptr->transformations |= PNG_EXPAND;\r
+#else\r
+ {\r
+ png_warning(png_ptr,\r
+ "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");\r
+ png_ptr->transformations &= ~PNG_RGB_TO_GRAY;\r
+ }\r
+#endif\r
+ {\r
+ png_uint_16 red_int, green_int;\r
+ if (red < 0 || green < 0)\r
+ {\r
+ red_int = 6968; /* .212671 * 32768 + .5 */\r
+ green_int = 23434; /* .715160 * 32768 + .5 */\r
+ }\r
+ else if (red + green < 100000L)\r
+ {\r
+ red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);\r
+ green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);\r
+ }\r
+ else\r
+ {\r
+ png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");\r
+ red_int = 6968;\r
+ green_int = 23434;\r
+ }\r
+ png_ptr->rgb_to_gray_red_coeff = red_int;\r
+ png_ptr->rgb_to_gray_green_coeff = green_int;\r
+ png_ptr->rgb_to_gray_blue_coeff = \r
+ (png_uint_16)(32768 - red_int - green_int);\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \\r
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \\r
+ defined(PNG_LEGACY_SUPPORTED)\r
+void PNGAPI\r
+png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr\r
+ read_user_transform_fn)\r
+{\r
+ png_debug(1, "in png_set_read_user_transform_fn\n");\r
+ if (png_ptr == NULL) return;\r
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)\r
+ png_ptr->transformations |= PNG_USER_TRANSFORM;\r
+ png_ptr->read_user_transform_fn = read_user_transform_fn;\r
+#endif\r
+#ifdef PNG_LEGACY_SUPPORTED\r
+ if (read_user_transform_fn)\r
+ png_warning(png_ptr,\r
+ "This version of libpng does not support user transforms");\r
+#endif\r
+}\r
+#endif\r
+\r
+/* Initialize everything needed for the read. This includes modifying\r
+ * the palette.\r
+ */\r
+void /* PRIVATE */\r
+png_init_read_transformations(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_init_read_transformations\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (png_ptr != NULL)\r
+#endif\r
+ {\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \\r
+ || defined(PNG_READ_GAMMA_SUPPORTED)\r
+ int color_type = png_ptr->color_type;\r
+#endif\r
+\r
+#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+\r
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)\r
+ /* Detect gray background and attempt to enable optimization\r
+ * for gray --> RGB case */\r
+ /* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or\r
+ * RGB_ALPHA (in which case need_expand is superfluous anyway), the\r
+ * background color might actually be gray yet not be flagged as such.\r
+ * This is not a problem for the current code, which uses\r
+ * PNG_BACKGROUND_IS_GRAY only to decide when to do the\r
+ * png_do_gray_to_rgb() transformation.\r
+ */\r
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&\r
+ !(color_type & PNG_COLOR_MASK_COLOR))\r
+ {\r
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;\r
+ } else if ((png_ptr->transformations & PNG_BACKGROUND) &&\r
+ !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&\r
+ (png_ptr->transformations & PNG_GRAY_TO_RGB) &&\r
+ png_ptr->background.red == png_ptr->background.green &&\r
+ png_ptr->background.red == png_ptr->background.blue)\r
+ {\r
+ png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;\r
+ png_ptr->background.gray = png_ptr->background.red;\r
+ }\r
+#endif\r
+\r
+ if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&\r
+ (png_ptr->transformations & PNG_EXPAND))\r
+ {\r
+ if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */\r
+ {\r
+ /* expand background and tRNS chunks */\r
+ switch (png_ptr->bit_depth)\r
+ {\r
+ case 1:\r
+ png_ptr->background.gray *= (png_uint_16)0xff;\r
+ png_ptr->background.red = png_ptr->background.green\r
+ = png_ptr->background.blue = png_ptr->background.gray;\r
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))\r
+ {\r
+ png_ptr->trans_values.gray *= (png_uint_16)0xff;\r
+ png_ptr->trans_values.red = png_ptr->trans_values.green\r
+ = png_ptr->trans_values.blue = png_ptr->trans_values.gray;\r
+ }\r
+ break;\r
+ case 2:\r
+ png_ptr->background.gray *= (png_uint_16)0x55;\r
+ png_ptr->background.red = png_ptr->background.green\r
+ = png_ptr->background.blue = png_ptr->background.gray;\r
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))\r
+ {\r
+ png_ptr->trans_values.gray *= (png_uint_16)0x55;\r
+ png_ptr->trans_values.red = png_ptr->trans_values.green\r
+ = png_ptr->trans_values.blue = png_ptr->trans_values.gray;\r
+ }\r
+ break;\r
+ case 4:\r
+ png_ptr->background.gray *= (png_uint_16)0x11;\r
+ png_ptr->background.red = png_ptr->background.green\r
+ = png_ptr->background.blue = png_ptr->background.gray;\r
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))\r
+ {\r
+ png_ptr->trans_values.gray *= (png_uint_16)0x11;\r
+ png_ptr->trans_values.red = png_ptr->trans_values.green\r
+ = png_ptr->trans_values.blue = png_ptr->trans_values.gray;\r
+ }\r
+ break;\r
+ case 8:\r
+ case 16:\r
+ png_ptr->background.red = png_ptr->background.green\r
+ = png_ptr->background.blue = png_ptr->background.gray;\r
+ break;\r
+ }\r
+ }\r
+ else if (color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ png_ptr->background.red =\r
+ png_ptr->palette[png_ptr->background.index].red;\r
+ png_ptr->background.green =\r
+ png_ptr->palette[png_ptr->background.index].green;\r
+ png_ptr->background.blue =\r
+ png_ptr->palette[png_ptr->background.index].blue;\r
+\r
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)\r
+ {\r
+#if defined(PNG_READ_EXPAND_SUPPORTED)\r
+ if (!(png_ptr->transformations & PNG_EXPAND_tRNS))\r
+#endif\r
+ {\r
+ /* invert the alpha channel (in tRNS) unless the pixels are\r
+ going to be expanded, in which case leave it for later */\r
+ int i, istop;\r
+ istop=(int)png_ptr->num_trans;\r
+ for (i=0; i<istop; i++)\r
+ png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);\r
+ }\r
+ }\r
+#endif\r
+\r
+ }\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED)\r
+ png_ptr->background_1 = png_ptr->background;\r
+#endif\r
+#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)\r
+\r
+ if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)\r
+ && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)\r
+ < PNG_GAMMA_THRESHOLD))\r
+ {\r
+ int i, k;\r
+ k=0;\r
+ for (i=0; i<png_ptr->num_trans; i++)\r
+ {\r
+ if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)\r
+ k=1; /* partial transparency is present */\r
+ }\r
+ if (k == 0)\r
+ png_ptr->transformations &= ~PNG_GAMMA;\r
+ }\r
+\r
+ if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&\r
+ png_ptr->gamma != 0.0)\r
+ {\r
+ png_build_gamma_table(png_ptr);\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_BACKGROUND)\r
+ {\r
+ if (color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ /* could skip if no transparency and\r
+ */\r
+ png_color back, back_1;\r
+ png_colorp palette = png_ptr->palette;\r
+ int num_palette = png_ptr->num_palette;\r
+ int i;\r
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)\r
+ {\r
+ back.red = png_ptr->gamma_table[png_ptr->background.red];\r
+ back.green = png_ptr->gamma_table[png_ptr->background.green];\r
+ back.blue = png_ptr->gamma_table[png_ptr->background.blue];\r
+\r
+ back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];\r
+ back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];\r
+ back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];\r
+ }\r
+ else\r
+ {\r
+ double g, gs;\r
+\r
+ switch (png_ptr->background_gamma_type)\r
+ {\r
+ case PNG_BACKGROUND_GAMMA_SCREEN:\r
+ g = (png_ptr->screen_gamma);\r
+ gs = 1.0;\r
+ break;\r
+ case PNG_BACKGROUND_GAMMA_FILE:\r
+ g = 1.0 / (png_ptr->gamma);\r
+ gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);\r
+ break;\r
+ case PNG_BACKGROUND_GAMMA_UNIQUE:\r
+ g = 1.0 / (png_ptr->background_gamma);\r
+ gs = 1.0 / (png_ptr->background_gamma *\r
+ png_ptr->screen_gamma);\r
+ break;\r
+ default:\r
+ g = 1.0; /* back_1 */\r
+ gs = 1.0; /* back */\r
+ }\r
+\r
+ if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD)\r
+ {\r
+ back.red = (png_byte)png_ptr->background.red;\r
+ back.green = (png_byte)png_ptr->background.green;\r
+ back.blue = (png_byte)png_ptr->background.blue;\r
+ }\r
+ else\r
+ {\r
+ back.red = (png_byte)(pow(\r
+ (double)png_ptr->background.red/255, gs) * 255.0 + .5);\r
+ back.green = (png_byte)(pow(\r
+ (double)png_ptr->background.green/255, gs) * 255.0 + .5);\r
+ back.blue = (png_byte)(pow(\r
+ (double)png_ptr->background.blue/255, gs) * 255.0 + .5);\r
+ }\r
+\r
+ back_1.red = (png_byte)(pow(\r
+ (double)png_ptr->background.red/255, g) * 255.0 + .5);\r
+ back_1.green = (png_byte)(pow(\r
+ (double)png_ptr->background.green/255, g) * 255.0 + .5);\r
+ back_1.blue = (png_byte)(pow(\r
+ (double)png_ptr->background.blue/255, g) * 255.0 + .5);\r
+ }\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)\r
+ {\r
+ if (png_ptr->trans[i] == 0)\r
+ {\r
+ palette[i] = back;\r
+ }\r
+ else /* if (png_ptr->trans[i] != 0xff) */\r
+ {\r
+ png_byte v, w;\r
+\r
+ v = png_ptr->gamma_to_1[palette[i].red];\r
+ png_composite(w, v, png_ptr->trans[i], back_1.red);\r
+ palette[i].red = png_ptr->gamma_from_1[w];\r
+\r
+ v = png_ptr->gamma_to_1[palette[i].green];\r
+ png_composite(w, v, png_ptr->trans[i], back_1.green);\r
+ palette[i].green = png_ptr->gamma_from_1[w];\r
+\r
+ v = png_ptr->gamma_to_1[palette[i].blue];\r
+ png_composite(w, v, png_ptr->trans[i], back_1.blue);\r
+ palette[i].blue = png_ptr->gamma_from_1[w];\r
+ }\r
+ }\r
+ else\r
+ {\r
+ palette[i].red = png_ptr->gamma_table[palette[i].red];\r
+ palette[i].green = png_ptr->gamma_table[palette[i].green];\r
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];\r
+ }\r
+ }\r
+ /* Prevent the transformations being done again, and make sure\r
+ * that the now spurious alpha channel is stripped - the code\r
+ * has just reduced background composition and gamma correction\r
+ * to a simple alpha channel strip.\r
+ */\r
+ png_ptr->transformations &= ~PNG_BACKGROUND;\r
+ png_ptr->transformations &= ~PNG_GAMMA;\r
+ png_ptr->transformations |= PNG_STRIP_ALPHA;\r
+ }\r
+ /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */\r
+ else\r
+ /* color_type != PNG_COLOR_TYPE_PALETTE */\r
+ {\r
+ double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1);\r
+ double g = 1.0;\r
+ double gs = 1.0;\r
+\r
+ switch (png_ptr->background_gamma_type)\r
+ {\r
+ case PNG_BACKGROUND_GAMMA_SCREEN:\r
+ g = (png_ptr->screen_gamma);\r
+ gs = 1.0;\r
+ break;\r
+ case PNG_BACKGROUND_GAMMA_FILE:\r
+ g = 1.0 / (png_ptr->gamma);\r
+ gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);\r
+ break;\r
+ case PNG_BACKGROUND_GAMMA_UNIQUE:\r
+ g = 1.0 / (png_ptr->background_gamma);\r
+ gs = 1.0 / (png_ptr->background_gamma *\r
+ png_ptr->screen_gamma);\r
+ break;\r
+ }\r
+\r
+ png_ptr->background_1.gray = (png_uint_16)(pow(\r
+ (double)png_ptr->background.gray / m, g) * m + .5);\r
+ png_ptr->background.gray = (png_uint_16)(pow(\r
+ (double)png_ptr->background.gray / m, gs) * m + .5);\r
+\r
+ if ((png_ptr->background.red != png_ptr->background.green) ||\r
+ (png_ptr->background.red != png_ptr->background.blue) ||\r
+ (png_ptr->background.red != png_ptr->background.gray))\r
+ {\r
+ /* RGB or RGBA with color background */\r
+ png_ptr->background_1.red = (png_uint_16)(pow(\r
+ (double)png_ptr->background.red / m, g) * m + .5);\r
+ png_ptr->background_1.green = (png_uint_16)(pow(\r
+ (double)png_ptr->background.green / m, g) * m + .5);\r
+ png_ptr->background_1.blue = (png_uint_16)(pow(\r
+ (double)png_ptr->background.blue / m, g) * m + .5);\r
+ png_ptr->background.red = (png_uint_16)(pow(\r
+ (double)png_ptr->background.red / m, gs) * m + .5);\r
+ png_ptr->background.green = (png_uint_16)(pow(\r
+ (double)png_ptr->background.green / m, gs) * m + .5);\r
+ png_ptr->background.blue = (png_uint_16)(pow(\r
+ (double)png_ptr->background.blue / m, gs) * m + .5);\r
+ }\r
+ else\r
+ {\r
+ /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */\r
+ png_ptr->background_1.red = png_ptr->background_1.green\r
+ = png_ptr->background_1.blue = png_ptr->background_1.gray;\r
+ png_ptr->background.red = png_ptr->background.green\r
+ = png_ptr->background.blue = png_ptr->background.gray;\r
+ }\r
+ }\r
+ }\r
+ else\r
+ /* transformation does not include PNG_BACKGROUND */\r
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */\r
+ if (color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ png_colorp palette = png_ptr->palette;\r
+ int num_palette = png_ptr->num_palette;\r
+ int i;\r
+\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ palette[i].red = png_ptr->gamma_table[palette[i].red];\r
+ palette[i].green = png_ptr->gamma_table[palette[i].green];\r
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];\r
+ }\r
+\r
+ /* Done the gamma correction. */\r
+ png_ptr->transformations &= ~PNG_GAMMA;\r
+ }\r
+ }\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ else\r
+#endif\r
+#endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ /* No GAMMA transformation */\r
+ if ((png_ptr->transformations & PNG_BACKGROUND) &&\r
+ (color_type == PNG_COLOR_TYPE_PALETTE))\r
+ {\r
+ int i;\r
+ int istop = (int)png_ptr->num_trans;\r
+ png_color back;\r
+ png_colorp palette = png_ptr->palette;\r
+\r
+ back.red = (png_byte)png_ptr->background.red;\r
+ back.green = (png_byte)png_ptr->background.green;\r
+ back.blue = (png_byte)png_ptr->background.blue;\r
+\r
+ for (i = 0; i < istop; i++)\r
+ {\r
+ if (png_ptr->trans[i] == 0)\r
+ {\r
+ palette[i] = back;\r
+ }\r
+ else if (png_ptr->trans[i] != 0xff)\r
+ {\r
+ /* The png_composite() macro is defined in png.h */\r
+ png_composite(palette[i].red, palette[i].red,\r
+ png_ptr->trans[i], back.red);\r
+ png_composite(palette[i].green, palette[i].green,\r
+ png_ptr->trans[i], back.green);\r
+ png_composite(palette[i].blue, palette[i].blue,\r
+ png_ptr->trans[i], back.blue);\r
+ }\r
+ }\r
+\r
+ /* Handled alpha, still need to strip the channel. */\r
+ png_ptr->transformations &= ~PNG_BACKGROUND;\r
+ png_ptr->transformations |= PNG_STRIP_ALPHA;\r
+ }\r
+#endif /* PNG_READ_BACKGROUND_SUPPORTED */\r
+\r
+#if defined(PNG_READ_SHIFT_SUPPORTED)\r
+ if ((png_ptr->transformations & PNG_SHIFT) &&\r
+ (color_type == PNG_COLOR_TYPE_PALETTE))\r
+ {\r
+ png_uint_16 i;\r
+ png_uint_16 istop = png_ptr->num_palette;\r
+ int sr = 8 - png_ptr->sig_bit.red;\r
+ int sg = 8 - png_ptr->sig_bit.green;\r
+ int sb = 8 - png_ptr->sig_bit.blue;\r
+\r
+ if (sr < 0 || sr > 8)\r
+ sr = 0;\r
+ if (sg < 0 || sg > 8)\r
+ sg = 0;\r
+ if (sb < 0 || sb > 8)\r
+ sb = 0;\r
+ for (i = 0; i < istop; i++)\r
+ {\r
+ png_ptr->palette[i].red >>= sr;\r
+ png_ptr->palette[i].green >>= sg;\r
+ png_ptr->palette[i].blue >>= sb;\r
+ }\r
+ }\r
+#endif /* PNG_READ_SHIFT_SUPPORTED */\r
+ }\r
+#if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \\r
+ && !defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr)\r
+ return;\r
+#endif\r
+}\r
+\r
+/* Modify the info structure to reflect the transformations. The\r
+ * info should be updated so a PNG file could be written with it,\r
+ * assuming the transformations result in valid PNG data.\r
+ */\r
+void /* PRIVATE */\r
+png_read_transform_info(png_structp png_ptr, png_infop info_ptr)\r
+{\r
+ png_debug(1, "in png_read_transform_info\n");\r
+#if defined(PNG_READ_EXPAND_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_EXPAND)\r
+ {\r
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ if (png_ptr->num_trans &&\r
+ (png_ptr->transformations & PNG_EXPAND_tRNS))\r
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;\r
+ else\r
+ info_ptr->color_type = PNG_COLOR_TYPE_RGB;\r
+ info_ptr->bit_depth = 8;\r
+ info_ptr->num_trans = 0;\r
+ }\r
+ else\r
+ {\r
+ if (png_ptr->num_trans)\r
+ {\r
+ if (png_ptr->transformations & PNG_EXPAND_tRNS)\r
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;\r
+#if 0 /* Removed from libpng-1.2.27 */\r
+ else\r
+ info_ptr->color_type |= PNG_COLOR_MASK_COLOR;\r
+#endif\r
+ }\r
+ if (info_ptr->bit_depth < 8)\r
+ info_ptr->bit_depth = 8;\r
+ info_ptr->num_trans = 0;\r
+ }\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_BACKGROUND)\r
+ {\r
+ info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;\r
+ info_ptr->num_trans = 0;\r
+ info_ptr->background = png_ptr->background;\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_GAMMA)\r
+ {\r
+#ifdef PNG_FLOATING_POINT_SUPPORTED\r
+ info_ptr->gamma = png_ptr->gamma;\r
+#endif\r
+#ifdef PNG_FIXED_POINT_SUPPORTED\r
+ info_ptr->int_gamma = png_ptr->int_gamma;\r
+#endif\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_READ_16_TO_8_SUPPORTED)\r
+ if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))\r
+ info_ptr->bit_depth = 8;\r
+#endif\r
+\r
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_GRAY_TO_RGB)\r
+ info_ptr->color_type |= PNG_COLOR_MASK_COLOR;\r
+#endif\r
+\r
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_RGB_TO_GRAY)\r
+ info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;\r
+#endif\r
+\r
+#if defined(PNG_READ_DITHER_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_DITHER)\r
+ {\r
+ if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||\r
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&\r
+ png_ptr->palette_lookup && info_ptr->bit_depth == 8)\r
+ {\r
+ info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;\r
+ }\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_READ_PACK_SUPPORTED)\r
+ if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))\r
+ info_ptr->bit_depth = 8;\r
+#endif\r
+\r
+ if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)\r
+ info_ptr->channels = 1;\r
+ else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR)\r
+ info_ptr->channels = 3;\r
+ else\r
+ info_ptr->channels = 1;\r
+\r
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)\r
+ if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)\r
+ info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;\r
+#endif\r
+\r
+ if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)\r
+ info_ptr->channels++;\r
+\r
+#if defined(PNG_READ_FILLER_SUPPORTED)\r
+ /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */\r
+ if ((png_ptr->transformations & PNG_FILLER) &&\r
+ ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||\r
+ (info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))\r
+ {\r
+ info_ptr->channels++;\r
+ /* if adding a true alpha channel not just filler */\r
+#if !defined(PNG_1_0_X)\r
+ if (png_ptr->transformations & PNG_ADD_ALPHA)\r
+ info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;\r
+#endif\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \\r
+defined(PNG_READ_USER_TRANSFORM_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)\r
+ {\r
+ if (info_ptr->bit_depth < png_ptr->user_transform_depth)\r
+ info_ptr->bit_depth = png_ptr->user_transform_depth;\r
+ if (info_ptr->channels < png_ptr->user_transform_channels)\r
+ info_ptr->channels = png_ptr->user_transform_channels;\r
+ }\r
+#endif\r
+\r
+ info_ptr->pixel_depth = (png_byte)(info_ptr->channels *\r
+ info_ptr->bit_depth);\r
+\r
+ info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);\r
+\r
+#if !defined(PNG_READ_EXPAND_SUPPORTED)\r
+ if (png_ptr)\r
+ return;\r
+#endif\r
+}\r
+\r
+/* Transform the row. The order of transformations is significant,\r
+ * and is very touchy. If you add a transformation, take care to\r
+ * decide how it fits in with the other transformations here.\r
+ */\r
+void /* PRIVATE */\r
+png_do_read_transformations(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_do_read_transformations\n");\r
+ if (png_ptr->row_buf == NULL)\r
+ {\r
+#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)\r
+ char msg[50];\r
+\r
+ png_snprintf2(msg, 50,\r
+ "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number,\r
+ png_ptr->pass);\r
+ png_error(png_ptr, msg);\r
+#else\r
+ png_error(png_ptr, "NULL row buffer");\r
+#endif\r
+ }\r
+#ifdef PNG_WARN_UNINITIALIZED_ROW\r
+ if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))\r
+ /* Application has failed to call either png_read_start_image()\r
+ * or png_read_update_info() after setting transforms that expand\r
+ * pixels. This check added to libpng-1.2.19 */\r
+#if (PNG_WARN_UNINITIALIZED_ROW==1)\r
+ png_error(png_ptr, "Uninitialized row");\r
+#else\r
+ png_warning(png_ptr, "Uninitialized row");\r
+#endif\r
+#endif\r
+\r
+#if defined(PNG_READ_EXPAND_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_EXPAND)\r
+ {\r
+ if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ png_ptr->palette, png_ptr->trans, png_ptr->num_trans);\r
+ }\r
+ else\r
+ {\r
+ if (png_ptr->num_trans &&\r
+ (png_ptr->transformations & PNG_EXPAND_tRNS))\r
+ png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ &(png_ptr->trans_values));\r
+ else\r
+ png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ NULL);\r
+ }\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)\r
+ if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)\r
+ png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));\r
+#endif\r
+\r
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_RGB_TO_GRAY)\r
+ {\r
+ int rgb_error =\r
+ png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);\r
+ if (rgb_error)\r
+ {\r
+ png_ptr->rgb_to_gray_status=1;\r
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == \r
+ PNG_RGB_TO_GRAY_WARN)\r
+ png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");\r
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==\r
+ PNG_RGB_TO_GRAY_ERR)\r
+ png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");\r
+ }\r
+ }\r
+#endif\r
+\r
+/*\r
+From Andreas Dilger e-mail to png-implement, 26 March 1998:\r
+\r
+ In most cases, the "simple transparency" should be done prior to doing\r
+ gray-to-RGB, or you will have to test 3x as many bytes to check if a\r
+ pixel is transparent. You would also need to make sure that the\r
+ transparency information is upgraded to RGB.\r
+\r
+ To summarize, the current flow is:\r
+ - Gray + simple transparency -> compare 1 or 2 gray bytes and composite\r
+ with background "in place" if transparent,\r
+ convert to RGB if necessary\r
+ - Gray + alpha -> composite with gray background and remove alpha bytes,\r
+ convert to RGB if necessary\r
+\r
+ To support RGB backgrounds for gray images we need:\r
+ - Gray + simple transparency -> convert to RGB + simple transparency, compare\r
+ 3 or 6 bytes and composite with background\r
+ "in place" if transparent (3x compare/pixel\r
+ compared to doing composite with gray bkgrnd)\r
+ - Gray + alpha -> convert to RGB + alpha, composite with background and\r
+ remove alpha bytes (3x float operations/pixel\r
+ compared with composite on gray background)\r
+\r
+ Greg's change will do this. The reason it wasn't done before is for\r
+ performance, as this increases the per-pixel operations. If we would check\r
+ in advance if the background was gray or RGB, and position the gray-to-RGB\r
+ transform appropriately, then it would save a lot of work/time.\r
+ */\r
+\r
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)\r
+ /* if gray -> RGB, do so now only if background is non-gray; else do later\r
+ * for performance reasons */\r
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&\r
+ !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))\r
+ png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if ((png_ptr->transformations & PNG_BACKGROUND) &&\r
+ ((png_ptr->num_trans != 0 ) ||\r
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))\r
+ png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ &(png_ptr->trans_values), &(png_ptr->background)\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ , &(png_ptr->background_1),\r
+ png_ptr->gamma_table, png_ptr->gamma_from_1,\r
+ png_ptr->gamma_to_1, png_ptr->gamma_16_table,\r
+ png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1,\r
+ png_ptr->gamma_shift\r
+#endif\r
+);\r
+#endif\r
+\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if ((png_ptr->transformations & PNG_GAMMA) &&\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ !((png_ptr->transformations & PNG_BACKGROUND) &&\r
+ ((png_ptr->num_trans != 0) ||\r
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&\r
+#endif\r
+ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))\r
+ png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ png_ptr->gamma_table, png_ptr->gamma_16_table,\r
+ png_ptr->gamma_shift);\r
+#endif\r
+\r
+#if defined(PNG_READ_16_TO_8_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_16_TO_8)\r
+ png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_DITHER_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_DITHER)\r
+ {\r
+ png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ png_ptr->palette_lookup, png_ptr->dither_index);\r
+ if (png_ptr->row_info.rowbytes == (png_uint_32)0)\r
+ png_error(png_ptr, "png_do_dither returned rowbytes=0");\r
+ }\r
+#endif\r
+\r
+#if defined(PNG_READ_INVERT_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_INVERT_MONO)\r
+ png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_SHIFT_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_SHIFT)\r
+ png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ &(png_ptr->shift));\r
+#endif\r
+\r
+#if defined(PNG_READ_PACK_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_PACK)\r
+ png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_BGR_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_BGR)\r
+ png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_PACKSWAP_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_PACKSWAP)\r
+ png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)\r
+ /* if gray -> RGB, do so now only if we did not do so above */\r
+ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&\r
+ (png_ptr->mode & PNG_BACKGROUND_IS_GRAY))\r
+ png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_FILLER_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_FILLER)\r
+ png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,\r
+ (png_uint_32)png_ptr->filler, png_ptr->flags);\r
+#endif\r
+\r
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_INVERT_ALPHA)\r
+ png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_SWAP_ALPHA)\r
+ png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_SWAP_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_SWAP_BYTES)\r
+ png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);\r
+#endif\r
+\r
+#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_USER_TRANSFORM)\r
+ {\r
+ if (png_ptr->read_user_transform_fn != NULL)\r
+ (*(png_ptr->read_user_transform_fn)) /* user read transform function */\r
+ (png_ptr, /* png_ptr */\r
+ &(png_ptr->row_info), /* row_info: */\r
+ /* png_uint_32 width; width of row */\r
+ /* png_uint_32 rowbytes; number of bytes in row */\r
+ /* png_byte color_type; color type of pixels */\r
+ /* png_byte bit_depth; bit depth of samples */\r
+ /* png_byte channels; number of channels (1-4) */\r
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */\r
+ png_ptr->row_buf + 1); /* start of pixel data for row */\r
+#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)\r
+ if (png_ptr->user_transform_depth)\r
+ png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;\r
+ if (png_ptr->user_transform_channels)\r
+ png_ptr->row_info.channels = png_ptr->user_transform_channels;\r
+#endif\r
+ png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth *\r
+ png_ptr->row_info.channels);\r
+ png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth,\r
+ png_ptr->row_info.width);\r
+ }\r
+#endif\r
+\r
+}\r
+\r
+#if defined(PNG_READ_PACK_SUPPORTED)\r
+/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,\r
+ * without changing the actual values. Thus, if you had a row with\r
+ * a bit depth of 1, you would end up with bytes that only contained\r
+ * the numbers 0 or 1. If you would rather they contain 0 and 255, use\r
+ * png_do_shift() after this.\r
+ */\r
+void /* PRIVATE */\r
+png_do_unpack(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_unpack\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL && row_info->bit_depth < 8)\r
+#else\r
+ if (row_info->bit_depth < 8)\r
+#endif\r
+ {\r
+ png_uint_32 i;\r
+ png_uint_32 row_width=row_info->width;\r
+\r
+ switch (row_info->bit_depth)\r
+ {\r
+ case 1:\r
+ {\r
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 3);\r
+ png_bytep dp = row + (png_size_t)row_width - 1;\r
+ png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *dp = (png_byte)((*sp >> shift) & 0x01);\r
+ if (shift == 7)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift++;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ case 2:\r
+ {\r
+\r
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 2);\r
+ png_bytep dp = row + (png_size_t)row_width - 1;\r
+ png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *dp = (png_byte)((*sp >> shift) & 0x03);\r
+ if (shift == 6)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift += 2;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+ png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);\r
+ png_bytep dp = row + (png_size_t)row_width - 1;\r
+ png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *dp = (png_byte)((*sp >> shift) & 0x0f);\r
+ if (shift == 4)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift = 4;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ row_info->bit_depth = 8;\r
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);\r
+ row_info->rowbytes = row_width * row_info->channels;\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_SHIFT_SUPPORTED)\r
+/* Reverse the effects of png_do_shift. This routine merely shifts the\r
+ * pixels back to their significant bits values. Thus, if you have\r
+ * a row of bit depth 8, but only 5 are significant, this will shift\r
+ * the values back to 0 through 31.\r
+ */\r
+void /* PRIVATE */\r
+png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)\r
+{\r
+ png_debug(1, "in png_do_unshift\n");\r
+ if (\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL && sig_bits != NULL &&\r
+#endif\r
+ row_info->color_type != PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ int shift[4];\r
+ int channels = 0;\r
+ int c;\r
+ png_uint_16 value = 0;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ if (row_info->color_type & PNG_COLOR_MASK_COLOR)\r
+ {\r
+ shift[channels++] = row_info->bit_depth - sig_bits->red;\r
+ shift[channels++] = row_info->bit_depth - sig_bits->green;\r
+ shift[channels++] = row_info->bit_depth - sig_bits->blue;\r
+ }\r
+ else\r
+ {\r
+ shift[channels++] = row_info->bit_depth - sig_bits->gray;\r
+ }\r
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)\r
+ {\r
+ shift[channels++] = row_info->bit_depth - sig_bits->alpha;\r
+ }\r
+\r
+ for (c = 0; c < channels; c++)\r
+ {\r
+ if (shift[c] <= 0)\r
+ shift[c] = 0;\r
+ else\r
+ value = 1;\r
+ }\r
+\r
+ if (!value)\r
+ return;\r
+\r
+ switch (row_info->bit_depth)\r
+ {\r
+ case 2:\r
+ {\r
+ png_bytep bp;\r
+ png_uint_32 i;\r
+ png_uint_32 istop = row_info->rowbytes;\r
+\r
+ for (bp = row, i = 0; i < istop; i++)\r
+ {\r
+ *bp >>= 1;\r
+ *bp++ &= 0x55;\r
+ }\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+ png_bytep bp = row;\r
+ png_uint_32 i;\r
+ png_uint_32 istop = row_info->rowbytes;\r
+ png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) |\r
+ (png_byte)((int)0xf >> shift[0]));\r
+\r
+ for (i = 0; i < istop; i++)\r
+ {\r
+ *bp >>= shift[0];\r
+ *bp++ &= mask;\r
+ }\r
+ break;\r
+ }\r
+ case 8:\r
+ {\r
+ png_bytep bp = row;\r
+ png_uint_32 i;\r
+ png_uint_32 istop = row_width * channels;\r
+\r
+ for (i = 0; i < istop; i++)\r
+ {\r
+ *bp++ >>= shift[i%channels];\r
+ }\r
+ break;\r
+ }\r
+ case 16:\r
+ {\r
+ png_bytep bp = row;\r
+ png_uint_32 i;\r
+ png_uint_32 istop = channels * row_width;\r
+\r
+ for (i = 0; i < istop; i++)\r
+ {\r
+ value = (png_uint_16)((*bp << 8) + *(bp + 1));\r
+ value >>= shift[i%channels];\r
+ *bp++ = (png_byte)(value >> 8);\r
+ *bp++ = (png_byte)(value & 0xff);\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_16_TO_8_SUPPORTED)\r
+/* chop rows of bit depth 16 down to 8 */\r
+void /* PRIVATE */\r
+png_do_chop(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_chop\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL && row_info->bit_depth == 16)\r
+#else\r
+ if (row_info->bit_depth == 16)\r
+#endif\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ png_uint_32 i;\r
+ png_uint_32 istop = row_info->width * row_info->channels;\r
+\r
+ for (i = 0; i<istop; i++, sp += 2, dp++)\r
+ {\r
+#if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED)\r
+ /* This does a more accurate scaling of the 16-bit color\r
+ * value, rather than a simple low-byte truncation.\r
+ *\r
+ * What the ideal calculation should be:\r
+ * *dp = (((((png_uint_32)(*sp) << 8) |\r
+ * (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L;\r
+ *\r
+ * GRR: no, I think this is what it really should be:\r
+ * *dp = (((((png_uint_32)(*sp) << 8) |\r
+ * (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L;\r
+ *\r
+ * GRR: here's the exact calculation with shifts:\r
+ * temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L;\r
+ * *dp = (temp - (temp >> 8)) >> 8;\r
+ *\r
+ * Approximate calculation with shift/add instead of multiply/divide:\r
+ * *dp = ((((png_uint_32)(*sp) << 8) |\r
+ * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8;\r
+ *\r
+ * What we actually do to avoid extra shifting and conversion:\r
+ */\r
+\r
+ *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);\r
+#else\r
+ /* Simply discard the low order byte */\r
+ *dp = *sp;\r
+#endif\r
+ }\r
+ row_info->bit_depth = 8;\r
+ row_info->pixel_depth = (png_byte)(8 * row_info->channels);\r
+ row_info->rowbytes = row_info->width * row_info->channels;\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)\r
+void /* PRIVATE */\r
+png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_read_swap_alpha\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL)\r
+#endif\r
+ {\r
+ png_uint_32 row_width = row_info->width;\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ {\r
+ /* This converts from RGBA to ARGB */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_byte save;\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ save = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = save;\r
+ }\r
+ }\r
+ /* This converts from RRGGBBAA to AARRGGBB */\r
+ else\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_byte save[2];\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ save[0] = *(--sp);\r
+ save[1] = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = save[0];\r
+ *(--dp) = save[1];\r
+ }\r
+ }\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)\r
+ {\r
+ /* This converts from GA to AG */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_byte save;\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ save = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = save;\r
+ }\r
+ }\r
+ /* This converts from GGAA to AAGG */\r
+ else\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_byte save[2];\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ save[0] = *(--sp);\r
+ save[1] = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = save[0];\r
+ *(--dp) = save[1];\r
+ }\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)\r
+void /* PRIVATE */\r
+png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_read_invert_alpha\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL)\r
+#endif\r
+ {\r
+ png_uint_32 row_width = row_info->width;\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ {\r
+ /* This inverts the alpha channel in RGBA */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = (png_byte)(255 - *(--sp));\r
+\r
+/* This does nothing:\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ We can replace it with:\r
+*/\r
+ sp-=3;\r
+ dp=sp;\r
+ }\r
+ }\r
+ /* This inverts the alpha channel in RRGGBBAA */\r
+ else\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = (png_byte)(255 - *(--sp));\r
+ *(--dp) = (png_byte)(255 - *(--sp));\r
+\r
+/* This does nothing:\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ We can replace it with:\r
+*/\r
+ sp-=6;\r
+ dp=sp;\r
+ }\r
+ }\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)\r
+ {\r
+ /* This inverts the alpha channel in GA */\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = (png_byte)(255 - *(--sp));\r
+ *(--dp) = *(--sp);\r
+ }\r
+ }\r
+ /* This inverts the alpha channel in GGAA */\r
+ else\r
+ {\r
+ png_bytep sp = row + row_info->rowbytes;\r
+ png_bytep dp = sp;\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = (png_byte)(255 - *(--sp));\r
+ *(--dp) = (png_byte)(255 - *(--sp));\r
+/*\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+*/\r
+ sp-=2;\r
+ dp=sp;\r
+ }\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_FILLER_SUPPORTED)\r
+/* Add filler channel if we have RGB color */\r
+void /* PRIVATE */\r
+png_do_read_filler(png_row_infop row_info, png_bytep row,\r
+ png_uint_32 filler, png_uint_32 flags)\r
+{\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ png_byte hi_filler = (png_byte)((filler>>8) & 0xff);\r
+ png_byte lo_filler = (png_byte)(filler & 0xff);\r
+\r
+ png_debug(1, "in png_do_read_filler\n");\r
+ if (\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ row_info->color_type == PNG_COLOR_TYPE_GRAY)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ /* This changes the data from G to GX */\r
+ if (flags & PNG_FLAG_FILLER_AFTER)\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width;\r
+ png_bytep dp = sp + (png_size_t)row_width;\r
+ for (i = 1; i < row_width; i++)\r
+ {\r
+ *(--dp) = lo_filler;\r
+ *(--dp) = *(--sp);\r
+ }\r
+ *(--dp) = lo_filler;\r
+ row_info->channels = 2;\r
+ row_info->pixel_depth = 16;\r
+ row_info->rowbytes = row_width * 2;\r
+ }\r
+ /* This changes the data from G to XG */\r
+ else\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width;\r
+ png_bytep dp = sp + (png_size_t)row_width;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = lo_filler;\r
+ }\r
+ row_info->channels = 2;\r
+ row_info->pixel_depth = 16;\r
+ row_info->rowbytes = row_width * 2;\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 16)\r
+ {\r
+ /* This changes the data from GG to GGXX */\r
+ if (flags & PNG_FLAG_FILLER_AFTER)\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 2;\r
+ png_bytep dp = sp + (png_size_t)row_width * 2;\r
+ for (i = 1; i < row_width; i++)\r
+ {\r
+ *(--dp) = hi_filler;\r
+ *(--dp) = lo_filler;\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ }\r
+ *(--dp) = hi_filler;\r
+ *(--dp) = lo_filler;\r
+ row_info->channels = 2;\r
+ row_info->pixel_depth = 32;\r
+ row_info->rowbytes = row_width * 4;\r
+ }\r
+ /* This changes the data from GG to XXGG */\r
+ else\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 2;\r
+ png_bytep dp = sp + (png_size_t)row_width * 2;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = hi_filler;\r
+ *(--dp) = lo_filler;\r
+ }\r
+ row_info->channels = 2;\r
+ row_info->pixel_depth = 32;\r
+ row_info->rowbytes = row_width * 4;\r
+ }\r
+ }\r
+ } /* COLOR_TYPE == GRAY */\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ /* This changes the data from RGB to RGBX */\r
+ if (flags & PNG_FLAG_FILLER_AFTER)\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 3;\r
+ png_bytep dp = sp + (png_size_t)row_width;\r
+ for (i = 1; i < row_width; i++)\r
+ {\r
+ *(--dp) = lo_filler;\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ }\r
+ *(--dp) = lo_filler;\r
+ row_info->channels = 4;\r
+ row_info->pixel_depth = 32;\r
+ row_info->rowbytes = row_width * 4;\r
+ }\r
+ /* This changes the data from RGB to XRGB */\r
+ else\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 3;\r
+ png_bytep dp = sp + (png_size_t)row_width;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = lo_filler;\r
+ }\r
+ row_info->channels = 4;\r
+ row_info->pixel_depth = 32;\r
+ row_info->rowbytes = row_width * 4;\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 16)\r
+ {\r
+ /* This changes the data from RRGGBB to RRGGBBXX */\r
+ if (flags & PNG_FLAG_FILLER_AFTER)\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 6;\r
+ png_bytep dp = sp + (png_size_t)row_width * 2;\r
+ for (i = 1; i < row_width; i++)\r
+ {\r
+ *(--dp) = hi_filler;\r
+ *(--dp) = lo_filler;\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ }\r
+ *(--dp) = hi_filler;\r
+ *(--dp) = lo_filler;\r
+ row_info->channels = 4;\r
+ row_info->pixel_depth = 64;\r
+ row_info->rowbytes = row_width * 8;\r
+ }\r
+ /* This changes the data from RRGGBB to XXRRGGBB */\r
+ else\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 6;\r
+ png_bytep dp = sp + (png_size_t)row_width * 2;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = *(--sp);\r
+ *(--dp) = hi_filler;\r
+ *(--dp) = lo_filler;\r
+ }\r
+ row_info->channels = 4;\r
+ row_info->pixel_depth = 64;\r
+ row_info->rowbytes = row_width * 8;\r
+ }\r
+ }\r
+ } /* COLOR_TYPE == RGB */\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)\r
+/* expand grayscale files to RGB, with or without alpha */\r
+void /* PRIVATE */\r
+png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_uint_32 i;\r
+ png_uint_32 row_width = row_info->width;\r
+\r
+ png_debug(1, "in png_do_gray_to_rgb\n");\r
+ if (row_info->bit_depth >= 8 &&\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ !(row_info->color_type & PNG_COLOR_MASK_COLOR))\r
+ {\r
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width - 1;\r
+ png_bytep dp = sp + (png_size_t)row_width * 2;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(dp--) = *sp;\r
+ *(dp--) = *sp;\r
+ *(dp--) = *(sp--);\r
+ }\r
+ }\r
+ else\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;\r
+ png_bytep dp = sp + (png_size_t)row_width * 4;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(dp--) = *sp;\r
+ *(dp--) = *(sp - 1);\r
+ *(dp--) = *sp;\r
+ *(dp--) = *(sp - 1);\r
+ *(dp--) = *(sp--);\r
+ *(dp--) = *(sp--);\r
+ }\r
+ }\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 2 - 1;\r
+ png_bytep dp = sp + (png_size_t)row_width * 2;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(dp--) = *(sp--);\r
+ *(dp--) = *sp;\r
+ *(dp--) = *sp;\r
+ *(dp--) = *(sp--);\r
+ }\r
+ }\r
+ else\r
+ {\r
+ png_bytep sp = row + (png_size_t)row_width * 4 - 1;\r
+ png_bytep dp = sp + (png_size_t)row_width * 4;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *(dp--) = *(sp--);\r
+ *(dp--) = *(sp--);\r
+ *(dp--) = *sp;\r
+ *(dp--) = *(sp - 1);\r
+ *(dp--) = *sp;\r
+ *(dp--) = *(sp - 1);\r
+ *(dp--) = *(sp--);\r
+ *(dp--) = *(sp--);\r
+ }\r
+ }\r
+ }\r
+ row_info->channels += (png_byte)2;\r
+ row_info->color_type |= PNG_COLOR_MASK_COLOR;\r
+ row_info->pixel_depth = (png_byte)(row_info->channels *\r
+ row_info->bit_depth);\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)\r
+/* reduce RGB files to grayscale, with or without alpha\r
+ * using the equation given in Poynton's ColorFAQ at\r
+ * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008)\r
+ * New link:\r
+ * <http://www.poynton.com/notes/colour_and_gamma/>\r
+ * Charles Poynton poynton at poynton.com\r
+ *\r
+ * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B\r
+ *\r
+ * We approximate this with\r
+ *\r
+ * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B\r
+ *\r
+ * which can be expressed with integers as\r
+ *\r
+ * Y = (6969 * R + 23434 * G + 2365 * B)/32768\r
+ *\r
+ * The calculation is to be done in a linear colorspace.\r
+ *\r
+ * Other integer coefficents can be used via png_set_rgb_to_gray().\r
+ */\r
+int /* PRIVATE */\r
+png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)\r
+\r
+{\r
+ png_uint_32 i;\r
+\r
+ png_uint_32 row_width = row_info->width;\r
+ int rgb_error = 0;\r
+\r
+ png_debug(1, "in png_do_rgb_to_gray\n");\r
+ if (\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))\r
+ {\r
+ png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;\r
+ png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;\r
+ png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;\r
+\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_byte red = png_ptr->gamma_to_1[*(sp++)];\r
+ png_byte green = png_ptr->gamma_to_1[*(sp++)];\r
+ png_byte blue = png_ptr->gamma_to_1[*(sp++)];\r
+ if (red != green || red != blue)\r
+ {\r
+ rgb_error |= 1;\r
+ *(dp++) = png_ptr->gamma_from_1[\r
+ (rc*red + gc*green + bc*blue)>>15];\r
+ }\r
+ else\r
+ *(dp++) = *(sp - 1);\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_byte red = *(sp++);\r
+ png_byte green = *(sp++);\r
+ png_byte blue = *(sp++);\r
+ if (red != green || red != blue)\r
+ {\r
+ rgb_error |= 1;\r
+ *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);\r
+ }\r
+ else\r
+ *(dp++) = *(sp - 1);\r
+ }\r
+ }\r
+ }\r
+\r
+ else /* RGB bit_depth == 16 */\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr->gamma_16_to_1 != NULL &&\r
+ png_ptr->gamma_16_from_1 != NULL)\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 red, green, blue, w;\r
+\r
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+\r
+ if (red == green && red == blue)\r
+ w = red;\r
+ else\r
+ {\r
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>\r
+ png_ptr->gamma_shift][red>>8];\r
+ png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>\r
+ png_ptr->gamma_shift][green>>8];\r
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>\r
+ png_ptr->gamma_shift][blue>>8];\r
+ png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1\r
+ + bc*blue_1)>>15);\r
+ w = png_ptr->gamma_16_from_1[(gray16&0xff) >>\r
+ png_ptr->gamma_shift][gray16 >> 8];\r
+ rgb_error |= 1;\r
+ }\r
+\r
+ *(dp++) = (png_byte)((w>>8) & 0xff);\r
+ *(dp++) = (png_byte)(w & 0xff);\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 red, green, blue, gray16;\r
+\r
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+\r
+ if (red != green || red != blue)\r
+ rgb_error |= 1;\r
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);\r
+ *(dp++) = (png_byte)((gray16>>8) & 0xff);\r
+ *(dp++) = (png_byte)(gray16 & 0xff);\r
+ }\r
+ }\r
+ }\r
+ }\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL)\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_byte red = png_ptr->gamma_to_1[*(sp++)];\r
+ png_byte green = png_ptr->gamma_to_1[*(sp++)];\r
+ png_byte blue = png_ptr->gamma_to_1[*(sp++)];\r
+ if (red != green || red != blue)\r
+ rgb_error |= 1;\r
+ *(dp++) = png_ptr->gamma_from_1\r
+ [(rc*red + gc*green + bc*blue)>>15];\r
+ *(dp++) = *(sp++); /* alpha */\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_byte red = *(sp++);\r
+ png_byte green = *(sp++);\r
+ png_byte blue = *(sp++);\r
+ if (red != green || red != blue)\r
+ rgb_error |= 1;\r
+ *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15);\r
+ *(dp++) = *(sp++); /* alpha */\r
+ }\r
+ }\r
+ }\r
+ else /* RGBA bit_depth == 16 */\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr->gamma_16_to_1 != NULL &&\r
+ png_ptr->gamma_16_from_1 != NULL)\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 red, green, blue, w;\r
+\r
+ red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+ green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+ blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2;\r
+\r
+ if (red == green && red == blue)\r
+ w = red;\r
+ else\r
+ {\r
+ png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>\r
+ png_ptr->gamma_shift][red>>8];\r
+ png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>\r
+ png_ptr->gamma_shift][green>>8];\r
+ png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>\r
+ png_ptr->gamma_shift][blue>>8];\r
+ png_uint_16 gray16 = (png_uint_16)((rc * red_1\r
+ + gc * green_1 + bc * blue_1)>>15);\r
+ w = png_ptr->gamma_16_from_1[(gray16&0xff) >>\r
+ png_ptr->gamma_shift][gray16 >> 8];\r
+ rgb_error |= 1;\r
+ }\r
+\r
+ *(dp++) = (png_byte)((w>>8) & 0xff);\r
+ *(dp++) = (png_byte)(w & 0xff);\r
+ *(dp++) = *(sp++); /* alpha */\r
+ *(dp++) = *(sp++);\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ png_bytep sp = row;\r
+ png_bytep dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 red, green, blue, gray16;\r
+ red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;\r
+ green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;\r
+ blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;\r
+ if (red != green || red != blue)\r
+ rgb_error |= 1;\r
+ gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);\r
+ *(dp++) = (png_byte)((gray16>>8) & 0xff);\r
+ *(dp++) = (png_byte)(gray16 & 0xff);\r
+ *(dp++) = *(sp++); /* alpha */\r
+ *(dp++) = *(sp++);\r
+ }\r
+ }\r
+ }\r
+ }\r
+ row_info->channels -= (png_byte)2;\r
+ row_info->color_type &= ~PNG_COLOR_MASK_COLOR;\r
+ row_info->pixel_depth = (png_byte)(row_info->channels *\r
+ row_info->bit_depth);\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);\r
+ }\r
+ return rgb_error;\r
+}\r
+#endif\r
+\r
+/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth\r
+ * large of png_color. This lets grayscale images be treated as\r
+ * paletted. Most useful for gamma correction and simplification\r
+ * of code.\r
+ */\r
+void PNGAPI\r
+png_build_grayscale_palette(int bit_depth, png_colorp palette)\r
+{\r
+ int num_palette;\r
+ int color_inc;\r
+ int i;\r
+ int v;\r
+\r
+ png_debug(1, "in png_do_build_grayscale_palette\n");\r
+ if (palette == NULL)\r
+ return;\r
+\r
+ switch (bit_depth)\r
+ {\r
+ case 1:\r
+ num_palette = 2;\r
+ color_inc = 0xff;\r
+ break;\r
+ case 2:\r
+ num_palette = 4;\r
+ color_inc = 0x55;\r
+ break;\r
+ case 4:\r
+ num_palette = 16;\r
+ color_inc = 0x11;\r
+ break;\r
+ case 8:\r
+ num_palette = 256;\r
+ color_inc = 1;\r
+ break;\r
+ default:\r
+ num_palette = 0;\r
+ color_inc = 0;\r
+ break;\r
+ }\r
+\r
+ for (i = 0, v = 0; i < num_palette; i++, v += color_inc)\r
+ {\r
+ palette[i].red = (png_byte)v;\r
+ palette[i].green = (png_byte)v;\r
+ palette[i].blue = (png_byte)v;\r
+ }\r
+}\r
+\r
+/* This function is currently unused. Do we really need it? */\r
+#if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED)\r
+void /* PRIVATE */\r
+png_correct_palette(png_structp png_ptr, png_colorp palette,\r
+ int num_palette)\r
+{\r
+ png_debug(1, "in png_correct_palette\n");\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \\r
+ defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)\r
+ if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))\r
+ {\r
+ png_color back, back_1;\r
+\r
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)\r
+ {\r
+ back.red = png_ptr->gamma_table[png_ptr->background.red];\r
+ back.green = png_ptr->gamma_table[png_ptr->background.green];\r
+ back.blue = png_ptr->gamma_table[png_ptr->background.blue];\r
+\r
+ back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];\r
+ back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];\r
+ back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];\r
+ }\r
+ else\r
+ {\r
+ double g;\r
+\r
+ g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);\r
+\r
+ if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN ||\r
+ fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)\r
+ {\r
+ back.red = png_ptr->background.red;\r
+ back.green = png_ptr->background.green;\r
+ back.blue = png_ptr->background.blue;\r
+ }\r
+ else\r
+ {\r
+ back.red =\r
+ (png_byte)(pow((double)png_ptr->background.red/255, g) *\r
+ 255.0 + 0.5);\r
+ back.green =\r
+ (png_byte)(pow((double)png_ptr->background.green/255, g) *\r
+ 255.0 + 0.5);\r
+ back.blue =\r
+ (png_byte)(pow((double)png_ptr->background.blue/255, g) *\r
+ 255.0 + 0.5);\r
+ }\r
+\r
+ g = 1.0 / png_ptr->background_gamma;\r
+\r
+ back_1.red =\r
+ (png_byte)(pow((double)png_ptr->background.red/255, g) *\r
+ 255.0 + 0.5);\r
+ back_1.green =\r
+ (png_byte)(pow((double)png_ptr->background.green/255, g) *\r
+ 255.0 + 0.5);\r
+ back_1.blue =\r
+ (png_byte)(pow((double)png_ptr->background.blue/255, g) *\r
+ 255.0 + 0.5);\r
+ }\r
+\r
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ png_uint_32 i;\r
+\r
+ for (i = 0; i < (png_uint_32)num_palette; i++)\r
+ {\r
+ if (i < png_ptr->num_trans && png_ptr->trans[i] == 0)\r
+ {\r
+ palette[i] = back;\r
+ }\r
+ else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff)\r
+ {\r
+ png_byte v, w;\r
+\r
+ v = png_ptr->gamma_to_1[png_ptr->palette[i].red];\r
+ png_composite(w, v, png_ptr->trans[i], back_1.red);\r
+ palette[i].red = png_ptr->gamma_from_1[w];\r
+\r
+ v = png_ptr->gamma_to_1[png_ptr->palette[i].green];\r
+ png_composite(w, v, png_ptr->trans[i], back_1.green);\r
+ palette[i].green = png_ptr->gamma_from_1[w];\r
+\r
+ v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];\r
+ png_composite(w, v, png_ptr->trans[i], back_1.blue);\r
+ palette[i].blue = png_ptr->gamma_from_1[w];\r
+ }\r
+ else\r
+ {\r
+ palette[i].red = png_ptr->gamma_table[palette[i].red];\r
+ palette[i].green = png_ptr->gamma_table[palette[i].green];\r
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];\r
+ }\r
+ }\r
+ }\r
+ else\r
+ {\r
+ int i;\r
+\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ if (palette[i].red == (png_byte)png_ptr->trans_values.gray)\r
+ {\r
+ palette[i] = back;\r
+ }\r
+ else\r
+ {\r
+ palette[i].red = png_ptr->gamma_table[palette[i].red];\r
+ palette[i].green = png_ptr->gamma_table[palette[i].green];\r
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];\r
+ }\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_GAMMA)\r
+ {\r
+ int i;\r
+\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ palette[i].red = png_ptr->gamma_table[palette[i].red];\r
+ palette[i].green = png_ptr->gamma_table[palette[i].green];\r
+ palette[i].blue = png_ptr->gamma_table[palette[i].blue];\r
+ }\r
+ }\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ else\r
+#endif\r
+#endif\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+ if (png_ptr->transformations & PNG_BACKGROUND)\r
+ {\r
+ if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ png_color back;\r
+\r
+ back.red = (png_byte)png_ptr->background.red;\r
+ back.green = (png_byte)png_ptr->background.green;\r
+ back.blue = (png_byte)png_ptr->background.blue;\r
+\r
+ for (i = 0; i < (int)png_ptr->num_trans; i++)\r
+ {\r
+ if (png_ptr->trans[i] == 0)\r
+ {\r
+ palette[i].red = back.red;\r
+ palette[i].green = back.green;\r
+ palette[i].blue = back.blue;\r
+ }\r
+ else if (png_ptr->trans[i] != 0xff)\r
+ {\r
+ png_composite(palette[i].red, png_ptr->palette[i].red,\r
+ png_ptr->trans[i], back.red);\r
+ png_composite(palette[i].green, png_ptr->palette[i].green,\r
+ png_ptr->trans[i], back.green);\r
+ png_composite(palette[i].blue, png_ptr->palette[i].blue,\r
+ png_ptr->trans[i], back.blue);\r
+ }\r
+ }\r
+ }\r
+ else /* assume grayscale palette (what else could it be?) */\r
+ {\r
+ int i;\r
+\r
+ for (i = 0; i < num_palette; i++)\r
+ {\r
+ if (i == (png_byte)png_ptr->trans_values.gray)\r
+ {\r
+ palette[i].red = (png_byte)png_ptr->background.red;\r
+ palette[i].green = (png_byte)png_ptr->background.green;\r
+ palette[i].blue = (png_byte)png_ptr->background.blue;\r
+ }\r
+ }\r
+ }\r
+ }\r
+#endif\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED)\r
+/* Replace any alpha or transparency with the supplied background color.\r
+ * "background" is already in the screen gamma, while "background_1" is\r
+ * at a gamma of 1.0. Paletted files have already been taken care of.\r
+ */\r
+void /* PRIVATE */\r
+png_do_background(png_row_infop row_info, png_bytep row,\r
+ png_color_16p trans_values, png_color_16p background\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ , png_color_16p background_1,\r
+ png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,\r
+ png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,\r
+ png_uint_16pp gamma_16_to_1, int gamma_shift\r
+#endif\r
+ )\r
+{\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width=row_info->width;\r
+ int shift;\r
+\r
+ png_debug(1, "in png_do_background\n");\r
+ if (background != NULL &&\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||\r
+ (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values)))\r
+ {\r
+ switch (row_info->color_type)\r
+ {\r
+ case PNG_COLOR_TYPE_GRAY:\r
+ {\r
+ switch (row_info->bit_depth)\r
+ {\r
+ case 1:\r
+ {\r
+ sp = row;\r
+ shift = 7;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((png_uint_16)((*sp >> shift) & 0x01)\r
+ == trans_values->gray)\r
+ {\r
+ *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);\r
+ *sp |= (png_byte)(background->gray << shift);\r
+ }\r
+ if (!shift)\r
+ {\r
+ shift = 7;\r
+ sp++;\r
+ }\r
+ else\r
+ shift--;\r
+ }\r
+ break;\r
+ }\r
+ case 2:\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_table != NULL)\r
+ {\r
+ sp = row;\r
+ shift = 6;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((png_uint_16)((*sp >> shift) & 0x03)\r
+ == trans_values->gray)\r
+ {\r
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);\r
+ *sp |= (png_byte)(background->gray << shift);\r
+ }\r
+ else\r
+ {\r
+ png_byte p = (png_byte)((*sp >> shift) & 0x03);\r
+ png_byte g = (png_byte)((gamma_table [p | (p << 2) |\r
+ (p << 4) | (p << 6)] >> 6) & 0x03);\r
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);\r
+ *sp |= (png_byte)(g << shift);\r
+ }\r
+ if (!shift)\r
+ {\r
+ shift = 6;\r
+ sp++;\r
+ }\r
+ else\r
+ shift -= 2;\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ shift = 6;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((png_uint_16)((*sp >> shift) & 0x03)\r
+ == trans_values->gray)\r
+ {\r
+ *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);\r
+ *sp |= (png_byte)(background->gray << shift);\r
+ }\r
+ if (!shift)\r
+ {\r
+ shift = 6;\r
+ sp++;\r
+ }\r
+ else\r
+ shift -= 2;\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_table != NULL)\r
+ {\r
+ sp = row;\r
+ shift = 4;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((png_uint_16)((*sp >> shift) & 0x0f)\r
+ == trans_values->gray)\r
+ {\r
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);\r
+ *sp |= (png_byte)(background->gray << shift);\r
+ }\r
+ else\r
+ {\r
+ png_byte p = (png_byte)((*sp >> shift) & 0x0f);\r
+ png_byte g = (png_byte)((gamma_table[p |\r
+ (p << 4)] >> 4) & 0x0f);\r
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);\r
+ *sp |= (png_byte)(g << shift);\r
+ }\r
+ if (!shift)\r
+ {\r
+ shift = 4;\r
+ sp++;\r
+ }\r
+ else\r
+ shift -= 4;\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ shift = 4;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((png_uint_16)((*sp >> shift) & 0x0f)\r
+ == trans_values->gray)\r
+ {\r
+ *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);\r
+ *sp |= (png_byte)(background->gray << shift);\r
+ }\r
+ if (!shift)\r
+ {\r
+ shift = 4;\r
+ sp++;\r
+ }\r
+ else\r
+ shift -= 4;\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case 8:\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_table != NULL)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp++)\r
+ {\r
+ if (*sp == trans_values->gray)\r
+ {\r
+ *sp = (png_byte)background->gray;\r
+ }\r
+ else\r
+ {\r
+ *sp = gamma_table[*sp];\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp++)\r
+ {\r
+ if (*sp == trans_values->gray)\r
+ {\r
+ *sp = (png_byte)background->gray;\r
+ }\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case 16:\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_16 != NULL)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp += 2)\r
+ {\r
+ png_uint_16 v;\r
+\r
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));\r
+ if (v == trans_values->gray)\r
+ {\r
+ /* background is already in screen gamma */\r
+ *sp = (png_byte)((background->gray >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(background->gray & 0xff);\r
+ }\r
+ else\r
+ {\r
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp += 2)\r
+ {\r
+ png_uint_16 v;\r
+\r
+ v = (png_uint_16)(((*sp) << 8) + *(sp + 1));\r
+ if (v == trans_values->gray)\r
+ {\r
+ *sp = (png_byte)((background->gray >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(background->gray & 0xff);\r
+ }\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case PNG_COLOR_TYPE_RGB:\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_table != NULL)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp += 3)\r
+ {\r
+ if (*sp == trans_values->red &&\r
+ *(sp + 1) == trans_values->green &&\r
+ *(sp + 2) == trans_values->blue)\r
+ {\r
+ *sp = (png_byte)background->red;\r
+ *(sp + 1) = (png_byte)background->green;\r
+ *(sp + 2) = (png_byte)background->blue;\r
+ }\r
+ else\r
+ {\r
+ *sp = gamma_table[*sp];\r
+ *(sp + 1) = gamma_table[*(sp + 1)];\r
+ *(sp + 2) = gamma_table[*(sp + 2)];\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp += 3)\r
+ {\r
+ if (*sp == trans_values->red &&\r
+ *(sp + 1) == trans_values->green &&\r
+ *(sp + 2) == trans_values->blue)\r
+ {\r
+ *sp = (png_byte)background->red;\r
+ *(sp + 1) = (png_byte)background->green;\r
+ *(sp + 2) = (png_byte)background->blue;\r
+ }\r
+ }\r
+ }\r
+ }\r
+ else /* if (row_info->bit_depth == 16) */\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_16 != NULL)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp += 6)\r
+ {\r
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));\r
+ png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));\r
+ png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));\r
+ if (r == trans_values->red && g == trans_values->green &&\r
+ b == trans_values->blue)\r
+ {\r
+ /* background is already in screen gamma */\r
+ *sp = (png_byte)((background->red >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(background->red & 0xff);\r
+ *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);\r
+ *(sp + 3) = (png_byte)(background->green & 0xff);\r
+ *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);\r
+ *(sp + 5) = (png_byte)(background->blue & 0xff);\r
+ }\r
+ else\r
+ {\r
+ png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];\r
+ *(sp + 2) = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 3) = (png_byte)(v & 0xff);\r
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];\r
+ *(sp + 4) = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 5) = (png_byte)(v & 0xff);\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp += 6)\r
+ {\r
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1));\r
+ png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));\r
+ png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));\r
+\r
+ if (r == trans_values->red && g == trans_values->green &&\r
+ b == trans_values->blue)\r
+ {\r
+ *sp = (png_byte)((background->red >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(background->red & 0xff);\r
+ *(sp + 2) = (png_byte)((background->green >> 8) & 0xff);\r
+ *(sp + 3) = (png_byte)(background->green & 0xff);\r
+ *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff);\r
+ *(sp + 5) = (png_byte)(background->blue & 0xff);\r
+ }\r
+ }\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case PNG_COLOR_TYPE_GRAY_ALPHA:\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&\r
+ gamma_table != NULL)\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 2, dp++)\r
+ {\r
+ png_uint_16 a = *(sp + 1);\r
+\r
+ if (a == 0xff)\r
+ {\r
+ *dp = gamma_table[*sp];\r
+ }\r
+ else if (a == 0)\r
+ {\r
+ /* background is already in screen gamma */\r
+ *dp = (png_byte)background->gray;\r
+ }\r
+ else\r
+ {\r
+ png_byte v, w;\r
+\r
+ v = gamma_to_1[*sp];\r
+ png_composite(w, v, a, background_1->gray);\r
+ *dp = gamma_from_1[w];\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 2, dp++)\r
+ {\r
+ png_byte a = *(sp + 1);\r
+\r
+ if (a == 0xff)\r
+ {\r
+ *dp = *sp;\r
+ }\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ else if (a == 0)\r
+ {\r
+ *dp = (png_byte)background->gray;\r
+ }\r
+ else\r
+ {\r
+ png_composite(*dp, *sp, a, background_1->gray);\r
+ }\r
+#else\r
+ *dp = (png_byte)background->gray;\r
+#endif\r
+ }\r
+ }\r
+ }\r
+ else /* if (png_ptr->bit_depth == 16) */\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&\r
+ gamma_16_to_1 != NULL)\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 4, dp += 2)\r
+ {\r
+ png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));\r
+\r
+ if (a == (png_uint_16)0xffff)\r
+ {\r
+ png_uint_16 v;\r
+\r
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];\r
+ *dp = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(v & 0xff);\r
+ }\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ else if (a == 0)\r
+#else\r
+ else\r
+#endif\r
+ {\r
+ /* background is already in screen gamma */\r
+ *dp = (png_byte)((background->gray >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(background->gray & 0xff);\r
+ }\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ else\r
+ {\r
+ png_uint_16 g, v, w;\r
+\r
+ g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];\r
+ png_composite_16(v, g, a, background_1->gray);\r
+ w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];\r
+ *dp = (png_byte)((w >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(w & 0xff);\r
+ }\r
+#endif\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 4, dp += 2)\r
+ {\r
+ png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));\r
+ if (a == (png_uint_16)0xffff)\r
+ {\r
+ png_memcpy(dp, sp, 2);\r
+ }\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ else if (a == 0)\r
+#else\r
+ else\r
+#endif\r
+ {\r
+ *dp = (png_byte)((background->gray >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(background->gray & 0xff);\r
+ }\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ else\r
+ {\r
+ png_uint_16 g, v;\r
+\r
+ g = (png_uint_16)(((*sp) << 8) + *(sp + 1));\r
+ png_composite_16(v, g, a, background_1->gray);\r
+ *dp = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(v & 0xff);\r
+ }\r
+#endif\r
+ }\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case PNG_COLOR_TYPE_RGB_ALPHA:\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_to_1 != NULL && gamma_from_1 != NULL &&\r
+ gamma_table != NULL)\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 4, dp += 3)\r
+ {\r
+ png_byte a = *(sp + 3);\r
+\r
+ if (a == 0xff)\r
+ {\r
+ *dp = gamma_table[*sp];\r
+ *(dp + 1) = gamma_table[*(sp + 1)];\r
+ *(dp + 2) = gamma_table[*(sp + 2)];\r
+ }\r
+ else if (a == 0)\r
+ {\r
+ /* background is already in screen gamma */\r
+ *dp = (png_byte)background->red;\r
+ *(dp + 1) = (png_byte)background->green;\r
+ *(dp + 2) = (png_byte)background->blue;\r
+ }\r
+ else\r
+ {\r
+ png_byte v, w;\r
+\r
+ v = gamma_to_1[*sp];\r
+ png_composite(w, v, a, background_1->red);\r
+ *dp = gamma_from_1[w];\r
+ v = gamma_to_1[*(sp + 1)];\r
+ png_composite(w, v, a, background_1->green);\r
+ *(dp + 1) = gamma_from_1[w];\r
+ v = gamma_to_1[*(sp + 2)];\r
+ png_composite(w, v, a, background_1->blue);\r
+ *(dp + 2) = gamma_from_1[w];\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 4, dp += 3)\r
+ {\r
+ png_byte a = *(sp + 3);\r
+\r
+ if (a == 0xff)\r
+ {\r
+ *dp = *sp;\r
+ *(dp + 1) = *(sp + 1);\r
+ *(dp + 2) = *(sp + 2);\r
+ }\r
+ else if (a == 0)\r
+ {\r
+ *dp = (png_byte)background->red;\r
+ *(dp + 1) = (png_byte)background->green;\r
+ *(dp + 2) = (png_byte)background->blue;\r
+ }\r
+ else\r
+ {\r
+ png_composite(*dp, *sp, a, background->red);\r
+ png_composite(*(dp + 1), *(sp + 1), a,\r
+ background->green);\r
+ png_composite(*(dp + 2), *(sp + 2), a,\r
+ background->blue);\r
+ }\r
+ }\r
+ }\r
+ }\r
+ else /* if (row_info->bit_depth == 16) */\r
+ {\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+ if (gamma_16 != NULL && gamma_16_from_1 != NULL &&\r
+ gamma_16_to_1 != NULL)\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 8, dp += 6)\r
+ {\r
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))\r
+ << 8) + (png_uint_16)(*(sp + 7)));\r
+ if (a == (png_uint_16)0xffff)\r
+ {\r
+ png_uint_16 v;\r
+\r
+ v = gamma_16[*(sp + 1) >> gamma_shift][*sp];\r
+ *dp = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(v & 0xff);\r
+ v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)];\r
+ *(dp + 2) = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 3) = (png_byte)(v & 0xff);\r
+ v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)];\r
+ *(dp + 4) = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 5) = (png_byte)(v & 0xff);\r
+ }\r
+ else if (a == 0)\r
+ {\r
+ /* background is already in screen gamma */\r
+ *dp = (png_byte)((background->red >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(background->red & 0xff);\r
+ *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);\r
+ *(dp + 3) = (png_byte)(background->green & 0xff);\r
+ *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);\r
+ *(dp + 5) = (png_byte)(background->blue & 0xff);\r
+ }\r
+ else\r
+ {\r
+ png_uint_16 v, w, x;\r
+\r
+ v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];\r
+ png_composite_16(w, v, a, background_1->red);\r
+ x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];\r
+ *dp = (png_byte)((x >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(x & 0xff);\r
+ v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];\r
+ png_composite_16(w, v, a, background_1->green);\r
+ x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];\r
+ *(dp + 2) = (png_byte)((x >> 8) & 0xff);\r
+ *(dp + 3) = (png_byte)(x & 0xff);\r
+ v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];\r
+ png_composite_16(w, v, a, background_1->blue);\r
+ x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];\r
+ *(dp + 4) = (png_byte)((x >> 8) & 0xff);\r
+ *(dp + 5) = (png_byte)(x & 0xff);\r
+ }\r
+ }\r
+ }\r
+ else\r
+#endif\r
+ {\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++, sp += 8, dp += 6)\r
+ {\r
+ png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6))\r
+ << 8) + (png_uint_16)(*(sp + 7)));\r
+ if (a == (png_uint_16)0xffff)\r
+ {\r
+ png_memcpy(dp, sp, 6);\r
+ }\r
+ else if (a == 0)\r
+ {\r
+ *dp = (png_byte)((background->red >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(background->red & 0xff);\r
+ *(dp + 2) = (png_byte)((background->green >> 8) & 0xff);\r
+ *(dp + 3) = (png_byte)(background->green & 0xff);\r
+ *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff);\r
+ *(dp + 5) = (png_byte)(background->blue & 0xff);\r
+ }\r
+ else\r
+ {\r
+ png_uint_16 v;\r
+\r
+ png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));\r
+ png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8)\r
+ + *(sp + 3));\r
+ png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8)\r
+ + *(sp + 5));\r
+\r
+ png_composite_16(v, r, a, background->red);\r
+ *dp = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 1) = (png_byte)(v & 0xff);\r
+ png_composite_16(v, g, a, background->green);\r
+ *(dp + 2) = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 3) = (png_byte)(v & 0xff);\r
+ png_composite_16(v, b, a, background->blue);\r
+ *(dp + 4) = (png_byte)((v >> 8) & 0xff);\r
+ *(dp + 5) = (png_byte)(v & 0xff);\r
+ }\r
+ }\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ }\r
+\r
+ if (row_info->color_type & PNG_COLOR_MASK_ALPHA)\r
+ {\r
+ row_info->color_type &= ~PNG_COLOR_MASK_ALPHA;\r
+ row_info->channels--;\r
+ row_info->pixel_depth = (png_byte)(row_info->channels *\r
+ row_info->bit_depth);\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+/* Gamma correct the image, avoiding the alpha channel. Make sure\r
+ * you do this after you deal with the transparency issue on grayscale\r
+ * or RGB images. If your bit depth is 8, use gamma_table, if it\r
+ * is 16, use gamma_16_table and gamma_shift. Build these with\r
+ * build_gamma_table().\r
+ */\r
+void /* PRIVATE */\r
+png_do_gamma(png_row_infop row_info, png_bytep row,\r
+ png_bytep gamma_table, png_uint_16pp gamma_16_table,\r
+ int gamma_shift)\r
+{\r
+ png_bytep sp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width=row_info->width;\r
+\r
+ png_debug(1, "in png_do_gamma\n");\r
+ if (\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ ((row_info->bit_depth <= 8 && gamma_table != NULL) ||\r
+ (row_info->bit_depth == 16 && gamma_16_table != NULL)))\r
+ {\r
+ switch (row_info->color_type)\r
+ {\r
+ case PNG_COLOR_TYPE_RGB:\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *sp = gamma_table[*sp];\r
+ sp++;\r
+ *sp = gamma_table[*sp];\r
+ sp++;\r
+ *sp = gamma_table[*sp];\r
+ sp++;\r
+ }\r
+ }\r
+ else /* if (row_info->bit_depth == 16) */\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 v;\r
+\r
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 2;\r
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 2;\r
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 2;\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case PNG_COLOR_TYPE_RGB_ALPHA:\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *sp = gamma_table[*sp];\r
+ sp++;\r
+ *sp = gamma_table[*sp];\r
+ sp++;\r
+ *sp = gamma_table[*sp];\r
+ sp++;\r
+ sp++;\r
+ }\r
+ }\r
+ else /* if (row_info->bit_depth == 16) */\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 2;\r
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 2;\r
+ v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 4;\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case PNG_COLOR_TYPE_GRAY_ALPHA:\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *sp = gamma_table[*sp];\r
+ sp += 2;\r
+ }\r
+ }\r
+ else /* if (row_info->bit_depth == 16) */\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 4;\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ case PNG_COLOR_TYPE_GRAY:\r
+ {\r
+ if (row_info->bit_depth == 2)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i += 4)\r
+ {\r
+ int a = *sp & 0xc0;\r
+ int b = *sp & 0x30;\r
+ int c = *sp & 0x0c;\r
+ int d = *sp & 0x03;\r
+\r
+ *sp = (png_byte)(\r
+ ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|\r
+ ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|\r
+ ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|\r
+ ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));\r
+ sp++;\r
+ }\r
+ }\r
+ if (row_info->bit_depth == 4)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i += 2)\r
+ {\r
+ int msb = *sp & 0xf0;\r
+ int lsb = *sp & 0x0f;\r
+\r
+ *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)\r
+ | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));\r
+ sp++;\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 8)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *sp = gamma_table[*sp];\r
+ sp++;\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 16)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp];\r
+ *sp = (png_byte)((v >> 8) & 0xff);\r
+ *(sp + 1) = (png_byte)(v & 0xff);\r
+ sp += 2;\r
+ }\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_EXPAND_SUPPORTED)\r
+/* Expands a palette row to an RGB or RGBA row depending\r
+ * upon whether you supply trans and num_trans.\r
+ */\r
+void /* PRIVATE */\r
+png_do_expand_palette(png_row_infop row_info, png_bytep row,\r
+ png_colorp palette, png_bytep trans, int num_trans)\r
+{\r
+ int shift, value;\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width=row_info->width;\r
+\r
+ png_debug(1, "in png_do_expand_palette\n");\r
+ if (\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ row_info->color_type == PNG_COLOR_TYPE_PALETTE)\r
+ {\r
+ if (row_info->bit_depth < 8)\r
+ {\r
+ switch (row_info->bit_depth)\r
+ {\r
+ case 1:\r
+ {\r
+ sp = row + (png_size_t)((row_width - 1) >> 3);\r
+ dp = row + (png_size_t)row_width - 1;\r
+ shift = 7 - (int)((row_width + 7) & 0x07);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((*sp >> shift) & 0x01)\r
+ *dp = 1;\r
+ else\r
+ *dp = 0;\r
+ if (shift == 7)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift++;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ case 2:\r
+ {\r
+ sp = row + (png_size_t)((row_width - 1) >> 2);\r
+ dp = row + (png_size_t)row_width - 1;\r
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ value = (*sp >> shift) & 0x03;\r
+ *dp = (png_byte)value;\r
+ if (shift == 6)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift += 2;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+ sp = row + (png_size_t)((row_width - 1) >> 1);\r
+ dp = row + (png_size_t)row_width - 1;\r
+ shift = (int)((row_width & 0x01) << 2);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ value = (*sp >> shift) & 0x0f;\r
+ *dp = (png_byte)value;\r
+ if (shift == 4)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift += 4;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ row_info->bit_depth = 8;\r
+ row_info->pixel_depth = 8;\r
+ row_info->rowbytes = row_width;\r
+ }\r
+ switch (row_info->bit_depth)\r
+ {\r
+ case 8:\r
+ {\r
+ if (trans != NULL)\r
+ {\r
+ sp = row + (png_size_t)row_width - 1;\r
+ dp = row + (png_size_t)(row_width << 2) - 1;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((int)(*sp) >= num_trans)\r
+ *dp-- = 0xff;\r
+ else\r
+ *dp-- = trans[*sp];\r
+ *dp-- = palette[*sp].blue;\r
+ *dp-- = palette[*sp].green;\r
+ *dp-- = palette[*sp].red;\r
+ sp--;\r
+ }\r
+ row_info->bit_depth = 8;\r
+ row_info->pixel_depth = 32;\r
+ row_info->rowbytes = row_width * 4;\r
+ row_info->color_type = 6;\r
+ row_info->channels = 4;\r
+ }\r
+ else\r
+ {\r
+ sp = row + (png_size_t)row_width - 1;\r
+ dp = row + (png_size_t)(row_width * 3) - 1;\r
+\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ *dp-- = palette[*sp].blue;\r
+ *dp-- = palette[*sp].green;\r
+ *dp-- = palette[*sp].red;\r
+ sp--;\r
+ }\r
+ row_info->bit_depth = 8;\r
+ row_info->pixel_depth = 24;\r
+ row_info->rowbytes = row_width * 3;\r
+ row_info->color_type = 2;\r
+ row_info->channels = 3;\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ }\r
+}\r
+\r
+/* If the bit depth < 8, it is expanded to 8. Also, if the already\r
+ * expanded transparency value is supplied, an alpha channel is built.\r
+ */\r
+void /* PRIVATE */\r
+png_do_expand(png_row_infop row_info, png_bytep row,\r
+ png_color_16p trans_value)\r
+{\r
+ int shift, value;\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width=row_info->width;\r
+\r
+ png_debug(1, "in png_do_expand\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL)\r
+#endif\r
+ {\r
+ if (row_info->color_type == PNG_COLOR_TYPE_GRAY)\r
+ {\r
+ png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0);\r
+\r
+ if (row_info->bit_depth < 8)\r
+ {\r
+ switch (row_info->bit_depth)\r
+ {\r
+ case 1:\r
+ {\r
+ gray = (png_uint_16)((gray&0x01)*0xff);\r
+ sp = row + (png_size_t)((row_width - 1) >> 3);\r
+ dp = row + (png_size_t)row_width - 1;\r
+ shift = 7 - (int)((row_width + 7) & 0x07);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if ((*sp >> shift) & 0x01)\r
+ *dp = 0xff;\r
+ else\r
+ *dp = 0;\r
+ if (shift == 7)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift++;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ case 2:\r
+ {\r
+ gray = (png_uint_16)((gray&0x03)*0x55);\r
+ sp = row + (png_size_t)((row_width - 1) >> 2);\r
+ dp = row + (png_size_t)row_width - 1;\r
+ shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ value = (*sp >> shift) & 0x03;\r
+ *dp = (png_byte)(value | (value << 2) | (value << 4) |\r
+ (value << 6));\r
+ if (shift == 6)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift += 2;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ case 4:\r
+ {\r
+ gray = (png_uint_16)((gray&0x0f)*0x11);\r
+ sp = row + (png_size_t)((row_width - 1) >> 1);\r
+ dp = row + (png_size_t)row_width - 1;\r
+ shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ value = (*sp >> shift) & 0x0f;\r
+ *dp = (png_byte)(value | (value << 4));\r
+ if (shift == 4)\r
+ {\r
+ shift = 0;\r
+ sp--;\r
+ }\r
+ else\r
+ shift = 4;\r
+\r
+ dp--;\r
+ }\r
+ break;\r
+ }\r
+ }\r
+ row_info->bit_depth = 8;\r
+ row_info->pixel_depth = 8;\r
+ row_info->rowbytes = row_width;\r
+ }\r
+\r
+ if (trans_value != NULL)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ gray = gray & 0xff;\r
+ sp = row + (png_size_t)row_width - 1;\r
+ dp = row + (png_size_t)(row_width << 1) - 1;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if (*sp == gray)\r
+ *dp-- = 0;\r
+ else\r
+ *dp-- = 0xff;\r
+ *dp-- = *sp--;\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 16)\r
+ {\r
+ png_byte gray_high = (gray >> 8) & 0xff;\r
+ png_byte gray_low = gray & 0xff;\r
+ sp = row + row_info->rowbytes - 1;\r
+ dp = row + (row_info->rowbytes << 1) - 1;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if (*(sp - 1) == gray_high && *(sp) == gray_low) \r
+ {\r
+ *dp-- = 0;\r
+ *dp-- = 0;\r
+ }\r
+ else\r
+ {\r
+ *dp-- = 0xff;\r
+ *dp-- = 0xff;\r
+ }\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ }\r
+ }\r
+ row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;\r
+ row_info->channels = 2;\r
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,\r
+ row_width);\r
+ }\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value)\r
+ {\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_byte red = trans_value->red & 0xff;\r
+ png_byte green = trans_value->green & 0xff;\r
+ png_byte blue = trans_value->blue & 0xff;\r
+ sp = row + (png_size_t)row_info->rowbytes - 1;\r
+ dp = row + (png_size_t)(row_width << 2) - 1;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)\r
+ *dp-- = 0;\r
+ else\r
+ *dp-- = 0xff;\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 16)\r
+ {\r
+ png_byte red_high = (trans_value->red >> 8) & 0xff;\r
+ png_byte green_high = (trans_value->green >> 8) & 0xff;\r
+ png_byte blue_high = (trans_value->blue >> 8) & 0xff;\r
+ png_byte red_low = trans_value->red & 0xff;\r
+ png_byte green_low = trans_value->green & 0xff;\r
+ png_byte blue_low = trans_value->blue & 0xff;\r
+ sp = row + row_info->rowbytes - 1;\r
+ dp = row + (png_size_t)(row_width << 3) - 1;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ if (*(sp - 5) == red_high &&\r
+ *(sp - 4) == red_low &&\r
+ *(sp - 3) == green_high &&\r
+ *(sp - 2) == green_low &&\r
+ *(sp - 1) == blue_high &&\r
+ *(sp ) == blue_low)\r
+ {\r
+ *dp-- = 0;\r
+ *dp-- = 0;\r
+ }\r
+ else\r
+ {\r
+ *dp-- = 0xff;\r
+ *dp-- = 0xff;\r
+ }\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ *dp-- = *sp--;\r
+ }\r
+ }\r
+ row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA;\r
+ row_info->channels = 4;\r
+ row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2);\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#if defined(PNG_READ_DITHER_SUPPORTED)\r
+void /* PRIVATE */\r
+png_do_dither(png_row_infop row_info, png_bytep row,\r
+ png_bytep palette_lookup, png_bytep dither_lookup)\r
+{\r
+ png_bytep sp, dp;\r
+ png_uint_32 i;\r
+ png_uint_32 row_width=row_info->width;\r
+\r
+ png_debug(1, "in png_do_dither\n");\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ if (row != NULL && row_info != NULL)\r
+#endif\r
+ {\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB &&\r
+ palette_lookup && row_info->bit_depth == 8)\r
+ {\r
+ int r, g, b, p;\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ r = *sp++;\r
+ g = *sp++;\r
+ b = *sp++;\r
+\r
+ /* this looks real messy, but the compiler will reduce\r
+ it down to a reasonable formula. For example, with\r
+ 5 bits per color, we get:\r
+ p = (((r >> 3) & 0x1f) << 10) |\r
+ (((g >> 3) & 0x1f) << 5) |\r
+ ((b >> 3) & 0x1f);\r
+ */\r
+ p = (((r >> (8 - PNG_DITHER_RED_BITS)) &\r
+ ((1 << PNG_DITHER_RED_BITS) - 1)) <<\r
+ (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |\r
+ (((g >> (8 - PNG_DITHER_GREEN_BITS)) &\r
+ ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<\r
+ (PNG_DITHER_BLUE_BITS)) |\r
+ ((b >> (8 - PNG_DITHER_BLUE_BITS)) &\r
+ ((1 << PNG_DITHER_BLUE_BITS) - 1));\r
+\r
+ *dp++ = palette_lookup[p];\r
+ }\r
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;\r
+ row_info->channels = 1;\r
+ row_info->pixel_depth = row_info->bit_depth;\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA &&\r
+ palette_lookup != NULL && row_info->bit_depth == 8)\r
+ {\r
+ int r, g, b, p;\r
+ sp = row;\r
+ dp = row;\r
+ for (i = 0; i < row_width; i++)\r
+ {\r
+ r = *sp++;\r
+ g = *sp++;\r
+ b = *sp++;\r
+ sp++;\r
+\r
+ p = (((r >> (8 - PNG_DITHER_RED_BITS)) &\r
+ ((1 << PNG_DITHER_RED_BITS) - 1)) <<\r
+ (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |\r
+ (((g >> (8 - PNG_DITHER_GREEN_BITS)) &\r
+ ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<\r
+ (PNG_DITHER_BLUE_BITS)) |\r
+ ((b >> (8 - PNG_DITHER_BLUE_BITS)) &\r
+ ((1 << PNG_DITHER_BLUE_BITS) - 1));\r
+\r
+ *dp++ = palette_lookup[p];\r
+ }\r
+ row_info->color_type = PNG_COLOR_TYPE_PALETTE;\r
+ row_info->channels = 1;\r
+ row_info->pixel_depth = row_info->bit_depth;\r
+ row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);\r
+ }\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&\r
+ dither_lookup && row_info->bit_depth == 8)\r
+ {\r
+ sp = row;\r
+ for (i = 0; i < row_width; i++, sp++)\r
+ {\r
+ *sp = dither_lookup[*sp];\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif\r
+\r
+#ifdef PNG_FLOATING_POINT_SUPPORTED\r
+#if defined(PNG_READ_GAMMA_SUPPORTED)\r
+static PNG_CONST int png_gamma_shift[] =\r
+ {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};\r
+\r
+/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit\r
+ * tables, we don't make a full table if we are reducing to 8-bit in\r
+ * the future. Note also how the gamma_16 tables are segmented so that\r
+ * we don't need to allocate > 64K chunks for a full 16-bit table.\r
+ */\r
+void /* PRIVATE */\r
+png_build_gamma_table(png_structp png_ptr)\r
+{\r
+ png_debug(1, "in png_build_gamma_table\n");\r
+\r
+ if (png_ptr->bit_depth <= 8)\r
+ {\r
+ int i;\r
+ double g;\r
+\r
+ if (png_ptr->screen_gamma > .000001)\r
+ g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);\r
+ else\r
+ g = 1.0;\r
+\r
+ png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)256);\r
+\r
+ for (i = 0; i < 256; i++)\r
+ {\r
+ png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0,\r
+ g) * 255.0 + .5);\r
+ }\r
+\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \\r
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)\r
+ if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY))\r
+ {\r
+\r
+ g = 1.0 / (png_ptr->gamma);\r
+\r
+ png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)256);\r
+\r
+ for (i = 0; i < 256; i++)\r
+ {\r
+ png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0,\r
+ g) * 255.0 + .5);\r
+ }\r
+\r
+\r
+ png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr,\r
+ (png_uint_32)256);\r
+\r
+ if (png_ptr->screen_gamma > 0.000001)\r
+ g = 1.0 / png_ptr->screen_gamma;\r
+ else\r
+ g = png_ptr->gamma; /* probably doing rgb_to_gray */\r
+\r
+ for (i = 0; i < 256; i++)\r
+ {\r
+ png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0,\r
+ g) * 255.0 + .5);\r
+\r
+ }\r
+ }\r
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */\r
+ }\r
+ else\r
+ {\r
+ double g;\r
+ int i, j, shift, num;\r
+ int sig_bit;\r
+ png_uint_32 ig;\r
+\r
+ if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)\r
+ {\r
+ sig_bit = (int)png_ptr->sig_bit.red;\r
+ if ((int)png_ptr->sig_bit.green > sig_bit)\r
+ sig_bit = png_ptr->sig_bit.green;\r
+ if ((int)png_ptr->sig_bit.blue > sig_bit)\r
+ sig_bit = png_ptr->sig_bit.blue;\r
+ }\r
+ else\r
+ {\r
+ sig_bit = (int)png_ptr->sig_bit.gray;\r
+ }\r
+\r
+ if (sig_bit > 0)\r
+ shift = 16 - sig_bit;\r
+ else\r
+ shift = 0;\r
+\r
+ if (png_ptr->transformations & PNG_16_TO_8)\r
+ {\r
+ if (shift < (16 - PNG_MAX_GAMMA_8))\r
+ shift = (16 - PNG_MAX_GAMMA_8);\r
+ }\r
+\r
+ if (shift > 8)\r
+ shift = 8;\r
+ if (shift < 0)\r
+ shift = 0;\r
+\r
+ png_ptr->gamma_shift = (png_byte)shift;\r
+\r
+ num = (1 << (8 - shift));\r
+\r
+ if (png_ptr->screen_gamma > .000001)\r
+ g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);\r
+ else\r
+ g = 1.0;\r
+\r
+ png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,\r
+ (png_uint_32)(num * png_sizeof(png_uint_16p)));\r
+\r
+ if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))\r
+ {\r
+ double fin, fout;\r
+ png_uint_32 last, max;\r
+\r
+ for (i = 0; i < num; i++)\r
+ {\r
+ png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,\r
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));\r
+ }\r
+\r
+ g = 1.0 / g;\r
+ last = 0;\r
+ for (i = 0; i < 256; i++)\r
+ {\r
+ fout = ((double)i + 0.5) / 256.0;\r
+ fin = pow(fout, g);\r
+ max = (png_uint_32)(fin * (double)((png_uint_32)num << 8));\r
+ while (last <= max)\r
+ {\r
+ png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]\r
+ [(int)(last >> (8 - shift))] = (png_uint_16)(\r
+ (png_uint_16)i | ((png_uint_16)i << 8));\r
+ last++;\r
+ }\r
+ }\r
+ while (last < ((png_uint_32)num << 8))\r
+ {\r
+ png_ptr->gamma_16_table[(int)(last & (0xff >> shift))]\r
+ [(int)(last >> (8 - shift))] = (png_uint_16)65535L;\r
+ last++;\r
+ }\r
+ }\r
+ else\r
+ {\r
+ for (i = 0; i < num; i++)\r
+ {\r
+ png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr,\r
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));\r
+\r
+ ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);\r
+ for (j = 0; j < 256; j++)\r
+ {\r
+ png_ptr->gamma_16_table[i][j] =\r
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /\r
+ 65535.0, g) * 65535.0 + .5);\r
+ }\r
+ }\r
+ }\r
+\r
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \\r
+ defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)\r
+ if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY))\r
+ {\r
+\r
+ g = 1.0 / (png_ptr->gamma);\r
+\r
+ png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,\r
+ (png_uint_32)(num * png_sizeof(png_uint_16p )));\r
+\r
+ for (i = 0; i < num; i++)\r
+ {\r
+ png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr,\r
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));\r
+\r
+ ig = (((png_uint_32)i *\r
+ (png_uint_32)png_gamma_shift[shift]) >> 4);\r
+ for (j = 0; j < 256; j++)\r
+ {\r
+ png_ptr->gamma_16_to_1[i][j] =\r
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /\r
+ 65535.0, g) * 65535.0 + .5);\r
+ }\r
+ }\r
+\r
+ if (png_ptr->screen_gamma > 0.000001)\r
+ g = 1.0 / png_ptr->screen_gamma;\r
+ else\r
+ g = png_ptr->gamma; /* probably doing rgb_to_gray */\r
+\r
+ png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,\r
+ (png_uint_32)(num * png_sizeof(png_uint_16p)));\r
+\r
+ for (i = 0; i < num; i++)\r
+ {\r
+ png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr,\r
+ (png_uint_32)(256 * png_sizeof(png_uint_16)));\r
+\r
+ ig = (((png_uint_32)i *\r
+ (png_uint_32)png_gamma_shift[shift]) >> 4);\r
+ for (j = 0; j < 256; j++)\r
+ {\r
+ png_ptr->gamma_16_from_1[i][j] =\r
+ (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) /\r
+ 65535.0, g) * 65535.0 + .5);\r
+ }\r
+ }\r
+ }\r
+#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */\r
+ }\r
+}\r
+#endif\r
+/* To do: install integer version of png_build_gamma_table here */\r
+#endif\r
+\r
+#if defined(PNG_MNG_FEATURES_SUPPORTED)\r
+/* undoes intrapixel differencing */\r
+void /* PRIVATE */\r
+png_do_read_intrapixel(png_row_infop row_info, png_bytep row)\r
+{\r
+ png_debug(1, "in png_do_read_intrapixel\n");\r
+ if (\r
+#if defined(PNG_USELESS_TESTS_SUPPORTED)\r
+ row != NULL && row_info != NULL &&\r
+#endif\r
+ (row_info->color_type & PNG_COLOR_MASK_COLOR))\r
+ {\r
+ int bytes_per_pixel;\r
+ png_uint_32 row_width = row_info->width;\r
+ if (row_info->bit_depth == 8)\r
+ {\r
+ png_bytep rp;\r
+ png_uint_32 i;\r
+\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)\r
+ bytes_per_pixel = 3;\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ bytes_per_pixel = 4;\r
+ else\r
+ return;\r
+\r
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)\r
+ {\r
+ *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff);\r
+ *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff);\r
+ }\r
+ }\r
+ else if (row_info->bit_depth == 16)\r
+ {\r
+ png_bytep rp;\r
+ png_uint_32 i;\r
+\r
+ if (row_info->color_type == PNG_COLOR_TYPE_RGB)\r
+ bytes_per_pixel = 6;\r
+ else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)\r
+ bytes_per_pixel = 8;\r
+ else\r
+ return;\r
+\r
+ for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)\r
+ {\r
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1);\r
+ png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3);\r
+ png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5);\r
+ png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL);\r
+ png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL);\r
+ *(rp ) = (png_byte)((red >> 8) & 0xff);\r
+ *(rp+1) = (png_byte)(red & 0xff);\r
+ *(rp+4) = (png_byte)((blue >> 8) & 0xff);\r
+ *(rp+5) = (png_byte)(blue & 0xff);\r
+ }\r
+ }\r
+ }\r
+}\r
+#endif /* PNG_MNG_FEATURES_SUPPORTED */\r
+#endif /* PNG_READ_SUPPORTED */\r
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