/* pngrtran.c - transforms the data in a row for PNG readers
*
- * Last changed in libpng 1.2.30 [August 15, 2008]
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * Last changed in libpng 1.4.2 [May 6, 2010]
+ * Copyright (c) 1998-2010 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
*
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
+ *
* This file contains functions optionally called by an application
* in order to tell libpng how to handle data when reading a PNG.
* Transformations that are used in both reading and writing are
* in pngtrans.c.
*/
-#define PNG_INTERNAL
+#define PNG_NO_PEDANTIC_WARNINGS
#include "png.h"
-#if defined(PNG_READ_SUPPORTED)
+#ifdef PNG_READ_SUPPORTED
+#include "pngpriv.h"
/* Set the action on getting a CRC error for an ancillary or critical chunk. */
void PNGAPI
png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
{
png_debug(1, "in png_set_crc_action");
+
+ if (png_ptr == NULL)
+ return;
+
/* Tell libpng how we react to CRC errors in critical chunks */
- if (png_ptr == NULL) return;
switch (crit_action)
{
- case PNG_CRC_NO_CHANGE: /* leave setting as is */
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
break;
- case PNG_CRC_WARN_USE: /* warn/use data */
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE;
break;
- case PNG_CRC_QUIET_USE: /* quiet/use data */
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE |
PNG_FLAG_CRC_CRITICAL_IGNORE;
break;
- case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */
+
+ case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */
png_warning(png_ptr,
- "Can't discard critical data on CRC error.");
- case PNG_CRC_ERROR_QUIT: /* error/quit */
+ "Can't discard critical data on CRC error");
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
+
case PNG_CRC_DEFAULT:
default:
png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK;
break;
}
+ /* Tell libpng how we react to CRC errors in ancillary chunks */
switch (ancil_action)
{
- case PNG_CRC_NO_CHANGE: /* leave setting as is */
+ case PNG_CRC_NO_CHANGE: /* Leave setting as is */
break;
- case PNG_CRC_WARN_USE: /* warn/use data */
+
+ case PNG_CRC_WARN_USE: /* Warn/use data */
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE;
break;
- case PNG_CRC_QUIET_USE: /* quiet/use data */
+
+ case PNG_CRC_QUIET_USE: /* Quiet/use data */
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE |
PNG_FLAG_CRC_ANCILLARY_NOWARN;
break;
- case PNG_CRC_ERROR_QUIT: /* error/quit */
+
+ case PNG_CRC_ERROR_QUIT: /* Error/quit */
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN;
break;
- case PNG_CRC_WARN_DISCARD: /* warn/discard data */
+
+ case PNG_CRC_WARN_DISCARD: /* Warn/discard data */
+
case PNG_CRC_DEFAULT:
default:
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
defined(PNG_FLOATING_POINT_SUPPORTED)
-/* handle alpha and tRNS via a background color */
+/* Handle alpha and tRNS via a background color */
void PNGAPI
png_set_background(png_structp png_ptr,
png_color_16p background_color, int background_gamma_code,
int need_expand, double background_gamma)
{
png_debug(1, "in png_set_background");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
{
png_warning(png_ptr, "Application must supply a known background gamma");
}
#endif
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
-/* strip 16 bit depth files to 8 bit depth */
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+/* Strip 16 bit depth files to 8 bit depth */
void PNGAPI
png_set_strip_16(png_structp png_ptr)
{
png_debug(1, "in png_set_strip_16");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
png_ptr->transformations |= PNG_16_TO_8;
}
#endif
-#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
void PNGAPI
png_set_strip_alpha(png_structp png_ptr)
{
png_debug(1, "in png_set_strip_alpha");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
}
#endif
-#if defined(PNG_READ_DITHER_SUPPORTED)
-/* Dither file to 8 bit. Supply a palette, the current number
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+/* Quantize file to 8 bit. Supply a palette, the current number
* of elements in the palette, the maximum number of elements
* allowed, and a histogram if possible. If the current number
* of colors is greater then the maximum number, the palette will be
- * modified to fit in the maximum number. "full_dither" indicates
- * whether we need a dithering cube set up for RGB images, or if we
+ * modified to fit in the maximum number. "full_quantize" indicates
+ * whether we need a quantizeing cube set up for RGB images, or if we
* simply are reducing the number of colors in a paletted image.
*/
typedef png_dsort FAR * FAR * png_dsortpp;
void PNGAPI
-png_set_dither(png_structp png_ptr, png_colorp palette,
+png_set_quantize(png_structp png_ptr, png_colorp palette,
int num_palette, int maximum_colors, png_uint_16p histogram,
- int full_dither)
+ int full_quantize)
{
- png_debug(1, "in png_set_dither");
- if (png_ptr == NULL) return;
- png_ptr->transformations |= PNG_DITHER;
+ png_debug(1, "in png_set_quantize");
- if (!full_dither)
+ if (png_ptr == NULL)
+ return;
+ png_ptr->transformations |= PNG_QUANTIZE;
+
+ if (!full_quantize)
{
int i;
- png_ptr->dither_index = (png_bytep)png_malloc(png_ptr,
+ png_ptr->quantize_index = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * png_sizeof(png_byte)));
for (i = 0; i < num_palette; i++)
- png_ptr->dither_index[i] = (png_byte)i;
+ png_ptr->quantize_index[i] = (png_byte)i;
}
if (num_palette > maximum_colors)
if (histogram != NULL)
{
/* This is easy enough, just throw out the least used colors.
- Perhaps not the best solution, but good enough. */
+ * Perhaps not the best solution, but good enough.
+ */
int i;
- /* initialize an array to sort colors */
- png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
+ /* Initialize an array to sort colors */
+ png_ptr->quantize_sort = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * png_sizeof(png_byte)));
- /* initialize the dither_sort array */
+ /* Initialize the quantize_sort array */
for (i = 0; i < num_palette; i++)
- png_ptr->dither_sort[i] = (png_byte)i;
+ png_ptr->quantize_sort[i] = (png_byte)i;
/* Find the least used palette entries by starting a
- bubble sort, and running it until we have sorted
- out enough colors. Note that we don't care about
- sorting all the colors, just finding which are
- least used. */
+ * bubble sort, and running it until we have sorted
+ * out enough colors. Note that we don't care about
+ * sorting all the colors, just finding which are
+ * least used.
+ */
for (i = num_palette - 1; i >= maximum_colors; i--)
{
- int done; /* to stop early if the list is pre-sorted */
+ int done; /* To stop early if the list is pre-sorted */
int j;
done = 1;
for (j = 0; j < i; j++)
{
- if (histogram[png_ptr->dither_sort[j]]
- < histogram[png_ptr->dither_sort[j + 1]])
+ if (histogram[png_ptr->quantize_sort[j]]
+ < histogram[png_ptr->quantize_sort[j + 1]])
{
png_byte t;
- t = png_ptr->dither_sort[j];
- png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
- png_ptr->dither_sort[j + 1] = t;
+ t = png_ptr->quantize_sort[j];
+ png_ptr->quantize_sort[j] = png_ptr->quantize_sort[j + 1];
+ png_ptr->quantize_sort[j + 1] = t;
done = 0;
}
}
break;
}
- /* swap the palette around, and set up a table, if necessary */
- if (full_dither)
+ /* Swap the palette around, and set up a table, if necessary */
+ if (full_quantize)
{
int j = num_palette;
- /* put all the useful colors within the max, but don't
- move the others */
+ /* Put all the useful colors within the max, but don't
+ * move the others.
+ */
for (i = 0; i < maximum_colors; i++)
{
- if ((int)png_ptr->dither_sort[i] >= maximum_colors)
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
{
do
j--;
- while ((int)png_ptr->dither_sort[j] >= maximum_colors);
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
palette[i] = palette[j];
}
}
{
int j = num_palette;
- /* move all the used colors inside the max limit, and
- develop a translation table */
+ /* Move all the used colors inside the max limit, and
+ * develop a translation table.
+ */
for (i = 0; i < maximum_colors; i++)
{
- /* only move the colors we need to */
- if ((int)png_ptr->dither_sort[i] >= maximum_colors)
+ /* Only move the colors we need to */
+ if ((int)png_ptr->quantize_sort[i] >= maximum_colors)
{
png_color tmp_color;
do
j--;
- while ((int)png_ptr->dither_sort[j] >= maximum_colors);
+ while ((int)png_ptr->quantize_sort[j] >= maximum_colors);
tmp_color = palette[j];
palette[j] = palette[i];
palette[i] = tmp_color;
- /* indicate where the color went */
- png_ptr->dither_index[j] = (png_byte)i;
- png_ptr->dither_index[i] = (png_byte)j;
+ /* Indicate where the color went */
+ png_ptr->quantize_index[j] = (png_byte)i;
+ png_ptr->quantize_index[i] = (png_byte)j;
}
}
- /* find closest color for those colors we are not using */
+ /* Find closest color for those colors we are not using */
for (i = 0; i < num_palette; i++)
{
- if ((int)png_ptr->dither_index[i] >= maximum_colors)
+ if ((int)png_ptr->quantize_index[i] >= maximum_colors)
{
int min_d, k, min_k, d_index;
- /* find the closest color to one we threw out */
- d_index = png_ptr->dither_index[i];
+ /* Find the closest color to one we threw out */
+ d_index = png_ptr->quantize_index[i];
min_d = PNG_COLOR_DIST(palette[d_index], palette[0]);
for (k = 1, min_k = 0; k < maximum_colors; k++)
{
min_k = k;
}
}
- /* point to closest color */
- png_ptr->dither_index[i] = (png_byte)min_k;
+ /* Point to closest color */
+ png_ptr->quantize_index[i] = (png_byte)min_k;
}
}
}
- png_free(png_ptr, png_ptr->dither_sort);
- png_ptr->dither_sort = NULL;
+ png_free(png_ptr, png_ptr->quantize_sort);
+ png_ptr->quantize_sort = NULL;
}
else
{
/* This is much harder to do simply (and quickly). Perhaps
- we need to go through a median cut routine, but those
- don't always behave themselves with only a few colors
- as input. So we will just find the closest two colors,
- and throw out one of them (chosen somewhat randomly).
- [We don't understand this at all, so if someone wants to
- work on improving it, be our guest - AED, GRP]
- */
+ * we need to go through a median cut routine, but those
+ * don't always behave themselves with only a few colors
+ * as input. So we will just find the closest two colors,
+ * and throw out one of them (chosen somewhat randomly).
+ * [We don't understand this at all, so if someone wants to
+ * work on improving it, be our guest - AED, GRP]
+ */
int i;
int max_d;
int num_new_palette;
t = NULL;
- /* initialize palette index arrays */
+ /* Initialize palette index arrays */
png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * png_sizeof(png_byte)));
png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * png_sizeof(png_byte)));
- /* initialize the sort array */
+ /* Initialize the sort array */
for (i = 0; i < num_palette; i++)
{
png_ptr->index_to_palette[i] = (png_byte)i;
png_ptr->palette_to_index[i] = (png_byte)i;
}
- hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 *
+ hash = (png_dsortpp)png_calloc(png_ptr, (png_uint_32)(769 *
png_sizeof(png_dsortp)));
- for (i = 0; i < 769; i++)
- hash[i] = NULL;
-/* png_memset(hash, 0, 769 * png_sizeof(png_dsortp)); */
num_new_palette = num_palette;
- /* initial wild guess at how far apart the farthest pixel
- pair we will be eliminating will be. Larger
- numbers mean more areas will be allocated, Smaller
- numbers run the risk of not saving enough data, and
- having to do this all over again.
-
- I have not done extensive checking on this number.
- */
+ /* Initial wild guess at how far apart the farthest pixel
+ * pair we will be eliminating will be. Larger
+ * numbers mean more areas will be allocated, Smaller
+ * numbers run the risk of not saving enough data, and
+ * having to do this all over again.
+ *
+ * I have not done extensive checking on this number.
+ */
max_d = 96;
while (num_new_palette > maximum_colors)
num_new_palette--;
palette[png_ptr->index_to_palette[j]]
= palette[num_new_palette];
- if (!full_dither)
+ if (!full_quantize)
{
int k;
for (k = 0; k < num_palette; k++)
{
- if (png_ptr->dither_index[k] ==
+ if (png_ptr->quantize_index[k] ==
png_ptr->index_to_palette[j])
- png_ptr->dither_index[k] =
+ png_ptr->quantize_index[k] =
png_ptr->index_to_palette[next_j];
- if ((int)png_ptr->dither_index[k] ==
+ if ((int)png_ptr->quantize_index[k] ==
num_new_palette)
- png_ptr->dither_index[k] =
+ png_ptr->quantize_index[k] =
png_ptr->index_to_palette[j];
}
}
png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
= png_ptr->palette_to_index[num_new_palette];
- png_ptr->index_to_palette[j] = (png_byte)num_new_palette;
- png_ptr->palette_to_index[num_new_palette] = (png_byte)j;
+ png_ptr->index_to_palette[j] =
+ (png_byte)num_new_palette;
+ png_ptr->palette_to_index[num_new_palette] =
+ (png_byte)j;
}
if (num_new_palette <= maximum_colors)
break;
}
png_ptr->num_palette = (png_uint_16)num_palette;
- if (full_dither)
+ if (full_quantize)
{
int i;
png_bytep distance;
- int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS +
- PNG_DITHER_BLUE_BITS;
- int num_red = (1 << PNG_DITHER_RED_BITS);
- int num_green = (1 << PNG_DITHER_GREEN_BITS);
- int num_blue = (1 << PNG_DITHER_BLUE_BITS);
+ int total_bits = PNG_QUANTIZE_RED_BITS + PNG_QUANTIZE_GREEN_BITS +
+ PNG_QUANTIZE_BLUE_BITS;
+ int num_red = (1 << PNG_QUANTIZE_RED_BITS);
+ int num_green = (1 << PNG_QUANTIZE_GREEN_BITS);
+ int num_blue = (1 << PNG_QUANTIZE_BLUE_BITS);
png_size_t num_entries = ((png_size_t)1 << total_bits);
- png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr,
+ png_ptr->palette_lookup = (png_bytep )png_calloc(png_ptr,
(png_uint_32)(num_entries * png_sizeof(png_byte)));
- png_memset(png_ptr->palette_lookup, 0, num_entries *
- png_sizeof(png_byte));
-
distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries *
png_sizeof(png_byte)));
-
png_memset(distance, 0xff, num_entries * png_sizeof(png_byte));
for (i = 0; i < num_palette; i++)
{
int ir, ig, ib;
- int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS));
- int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS));
- int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS));
+ int r = (palette[i].red >> (8 - PNG_QUANTIZE_RED_BITS));
+ int g = (palette[i].green >> (8 - PNG_QUANTIZE_GREEN_BITS));
+ int b = (palette[i].blue >> (8 - PNG_QUANTIZE_BLUE_BITS));
for (ir = 0; ir < num_red; ir++)
{
/* int dr = abs(ir - r); */
int dr = ((ir > r) ? ir - r : r - ir);
- int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS));
+ int index_r = (ir << (PNG_QUANTIZE_BLUE_BITS +
+ PNG_QUANTIZE_GREEN_BITS));
for (ig = 0; ig < num_green; ig++)
{
int dg = ((ig > g) ? ig - g : g - ig);
int dt = dr + dg;
int dm = ((dr > dg) ? dr : dg);
- int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS);
+ int index_g = index_r | (ig << PNG_QUANTIZE_BLUE_BITS);
for (ib = 0; ib < num_blue; ib++)
{
png_free(png_ptr, distance);
}
}
-#endif
+#endif /* PNG_READ_QUANTIZE_SUPPORTED */
#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
/* Transform the image from the file_gamma to the screen_gamma. We
png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
{
png_debug(1, "in png_set_gamma");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
+
if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
}
#endif
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+#ifdef PNG_READ_EXPAND_SUPPORTED
/* Expand paletted images to RGB, expand grayscale images of
* less than 8-bit depth to 8-bit depth, and expand tRNS chunks
* to alpha channels.
png_set_expand(png_structp png_ptr)
{
png_debug(1, "in png_set_expand");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
+
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
}
* More to the point, these functions make it obvious what libpng will be
* doing, whereas "expand" can (and does) mean any number of things.
*
- * GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified
- * to expand only the sample depth but not to expand the tRNS to alpha.
+ * GRP 20060307: In libpng-1.2.9, png_set_gray_1_2_4_to_8() was modified
+ * to expand only the sample depth but not to expand the tRNS to alpha
+ * and its name was changed to png_set_expand_gray_1_2_4_to_8().
*/
/* Expand paletted images to RGB. */
png_set_palette_to_rgb(png_structp png_ptr)
{
png_debug(1, "in png_set_palette_to_rgb");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
+
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
}
-#if !defined(PNG_1_0_X)
/* Expand grayscale images of less than 8-bit depth to 8 bits. */
void PNGAPI
png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
{
png_debug(1, "in png_set_expand_gray_1_2_4_to_8");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
+
png_ptr->transformations |= PNG_EXPAND;
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
}
-#endif
-#if defined(PNG_1_0_X) || defined(PNG_1_2_X)
-/* Expand grayscale images of less than 8-bit depth to 8 bits. */
-/* Deprecated as of libpng-1.2.9 */
-void PNGAPI
-png_set_gray_1_2_4_to_8(png_structp png_ptr)
-{
- png_debug(1, "in png_set_gray_1_2_4_to_8");
- if (png_ptr == NULL) return;
- png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
-}
-#endif
/* Expand tRNS chunks to alpha channels. */
png_set_tRNS_to_alpha(png_structp png_ptr)
{
png_debug(1, "in png_set_tRNS_to_alpha");
+
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
}
#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
void PNGAPI
png_set_gray_to_rgb(png_structp png_ptr)
{
png_debug(1, "in png_set_gray_to_rgb");
+
png_ptr->transformations |= PNG_GRAY_TO_RGB;
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
}
#endif
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-#if defined(PNG_FLOATING_POINT_SUPPORTED)
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+#ifdef PNG_FLOATING_POINT_SUPPORTED
/* Convert a RGB image to a grayscale of the same width. This allows us,
* for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
*/
png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
double green)
{
- int red_fixed = (int)((float)red*100000.0 + 0.5);
- int green_fixed = (int)((float)green*100000.0 + 0.5);
- if (png_ptr == NULL) return;
- png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
+ int red_fixed = (int)((float)red*100000.0 + 0.5);
+ int green_fixed = (int)((float)green*100000.0 + 0.5);
+ if (png_ptr == NULL)
+ return;
+ png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
}
#endif
png_fixed_point red, png_fixed_point green)
{
png_debug(1, "in png_set_rgb_to_gray");
- if (png_ptr == NULL) return;
+
+ if (png_ptr == NULL)
+ return;
+
switch(error_action)
{
case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
break;
+
case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN;
break;
+
case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR;
}
if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+#ifdef PNG_READ_EXPAND_SUPPORTED
png_ptr->transformations |= PNG_EXPAND;
#else
{
png_warning(png_ptr,
- "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED.");
+ "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED");
png_ptr->transformations &= ~PNG_RGB_TO_GRAY;
}
#endif
}
else if (red + green < 100000L)
{
- red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
- green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
+ red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
+ green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
}
else
{
}
png_ptr->rgb_to_gray_red_coeff = red_int;
png_ptr->rgb_to_gray_green_coeff = green_int;
- png_ptr->rgb_to_gray_blue_coeff =
+ png_ptr->rgb_to_gray_blue_coeff =
(png_uint_16)(32768 - red_int - green_int);
}
}
#endif
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \
- defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \
- defined(PNG_LEGACY_SUPPORTED)
+ defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
void PNGAPI
png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
read_user_transform_fn)
{
png_debug(1, "in png_set_read_user_transform_fn");
- if (png_ptr == NULL) return;
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+
+ if (png_ptr == NULL)
+ return;
+
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
png_ptr->transformations |= PNG_USER_TRANSFORM;
png_ptr->read_user_transform_fn = read_user_transform_fn;
#endif
-#ifdef PNG_LEGACY_SUPPORTED
- if (read_user_transform_fn)
- png_warning(png_ptr,
- "This version of libpng does not support user transforms");
-#endif
}
#endif
png_init_read_transformations(png_structp png_ptr)
{
png_debug(1, "in png_init_read_transformations");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (png_ptr != NULL)
-#endif
+
{
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \
- || defined(PNG_READ_GAMMA_SUPPORTED)
+#if defined(PNG_READ_BACKGROUND_SUPPORTED) || \
+ defined(PNG_READ_SHIFT_SUPPORTED) || \
+ defined(PNG_READ_GAMMA_SUPPORTED)
int color_type = png_ptr->color_type;
#endif
#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
/* Detect gray background and attempt to enable optimization
- * for gray --> RGB case */
- /* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
+ * for gray --> RGB case
+ *
+ * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
* RGB_ALPHA (in which case need_expand is superfluous anyway), the
* background color might actually be gray yet not be flagged as such.
* This is not a problem for the current code, which uses
{
if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */
{
- /* expand background and tRNS chunks */
+ /* Expand background and tRNS chunks */
switch (png_ptr->bit_depth)
{
case 1:
= png_ptr->background.blue = png_ptr->background.gray;
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
{
- png_ptr->trans_values.gray *= (png_uint_16)0xff;
- png_ptr->trans_values.red = png_ptr->trans_values.green
- = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
+ png_ptr->trans_color.gray *= (png_uint_16)0xff;
+ png_ptr->trans_color.red = png_ptr->trans_color.green
+ = png_ptr->trans_color.blue = png_ptr->trans_color.gray;
}
break;
+
case 2:
png_ptr->background.gray *= (png_uint_16)0x55;
png_ptr->background.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.gray;
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
{
- png_ptr->trans_values.gray *= (png_uint_16)0x55;
- png_ptr->trans_values.red = png_ptr->trans_values.green
- = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
+ png_ptr->trans_color.gray *= (png_uint_16)0x55;
+ png_ptr->trans_color.red = png_ptr->trans_color.green
+ = png_ptr->trans_color.blue = png_ptr->trans_color.gray;
}
break;
+
case 4:
png_ptr->background.gray *= (png_uint_16)0x11;
png_ptr->background.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.gray;
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
{
- png_ptr->trans_values.gray *= (png_uint_16)0x11;
- png_ptr->trans_values.red = png_ptr->trans_values.green
- = png_ptr->trans_values.blue = png_ptr->trans_values.gray;
+ png_ptr->trans_color.gray *= (png_uint_16)0x11;
+ png_ptr->trans_color.red = png_ptr->trans_color.green
+ = png_ptr->trans_color.blue = png_ptr->trans_color.gray;
}
break;
+
case 8:
+
case 16:
png_ptr->background.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.gray;
png_ptr->background.blue =
png_ptr->palette[png_ptr->background.index].blue;
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
if (png_ptr->transformations & PNG_INVERT_ALPHA)
{
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+#ifdef PNG_READ_EXPAND_SUPPORTED
if (!(png_ptr->transformations & PNG_EXPAND_tRNS))
#endif
{
- /* invert the alpha channel (in tRNS) unless the pixels are
- going to be expanded, in which case leave it for later */
+ /* Invert the alpha channel (in tRNS) unless the pixels are
+ * going to be expanded, in which case leave it for later
+ */
int i, istop;
istop=(int)png_ptr->num_trans;
for (i=0; i<istop; i++)
- png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]);
+ png_ptr->trans_alpha[i] = (png_byte)(255 - png_ptr->trans_alpha[i]);
}
}
#endif
k=0;
for (i=0; i<png_ptr->num_trans; i++)
{
- if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
- k=1; /* partial transparency is present */
+ if (png_ptr->trans_alpha[i] != 0 && png_ptr->trans_alpha[i] != 0xff)
+ k=1; /* Partial transparency is present */
}
if (k == 0)
png_ptr->transformations &= ~PNG_GAMMA;
if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
png_ptr->gamma != 0.0)
{
- png_build_gamma_table(png_ptr);
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+ png_build_gamma_table(png_ptr, png_ptr->bit_depth);
+
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
if (png_ptr->transformations & PNG_BACKGROUND)
{
if (color_type == PNG_COLOR_TYPE_PALETTE)
{
- /* could skip if no transparency and
- */
+ /* Could skip if no transparency */
png_color back, back_1;
png_colorp palette = png_ptr->palette;
int num_palette = png_ptr->num_palette;
g = (png_ptr->screen_gamma);
gs = 1.0;
break;
+
case PNG_BACKGROUND_GAMMA_FILE:
g = 1.0 / (png_ptr->gamma);
gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
break;
+
case PNG_BACKGROUND_GAMMA_UNIQUE:
g = 1.0 / (png_ptr->background_gamma);
gs = 1.0 / (png_ptr->background_gamma *
else
{
back.red = (png_byte)(pow(
- (double)png_ptr->background.red/255, gs) * 255.0 + .5);
+ (double)png_ptr->background.red/255.0, gs) * 255.0 + .5);
back.green = (png_byte)(pow(
- (double)png_ptr->background.green/255, gs) * 255.0 + .5);
+ (double)png_ptr->background.green/255.0, gs) * 255.0
+ + .5);
back.blue = (png_byte)(pow(
- (double)png_ptr->background.blue/255, gs) * 255.0 + .5);
+ (double)png_ptr->background.blue/255.0, gs) * 255.0 + .5);
}
back_1.red = (png_byte)(pow(
- (double)png_ptr->background.red/255, g) * 255.0 + .5);
+ (double)png_ptr->background.red/255.0, g) * 255.0 + .5);
back_1.green = (png_byte)(pow(
- (double)png_ptr->background.green/255, g) * 255.0 + .5);
+ (double)png_ptr->background.green/255.0, g) * 255.0 + .5);
back_1.blue = (png_byte)(pow(
- (double)png_ptr->background.blue/255, g) * 255.0 + .5);
+ (double)png_ptr->background.blue/255.0, g) * 255.0 + .5);
}
for (i = 0; i < num_palette; i++)
{
- if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff)
+ if (i < (int)png_ptr->num_trans && png_ptr->trans_alpha[i] != 0xff)
{
- if (png_ptr->trans[i] == 0)
+ if (png_ptr->trans_alpha[i] == 0)
{
palette[i] = back;
}
- else /* if (png_ptr->trans[i] != 0xff) */
+ else /* if (png_ptr->trans_alpha[i] != 0xff) */
{
png_byte v, w;
v = png_ptr->gamma_to_1[palette[i].red];
- png_composite(w, v, png_ptr->trans[i], back_1.red);
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.red);
palette[i].red = png_ptr->gamma_from_1[w];
v = png_ptr->gamma_to_1[palette[i].green];
- png_composite(w, v, png_ptr->trans[i], back_1.green);
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.green);
palette[i].green = png_ptr->gamma_from_1[w];
v = png_ptr->gamma_to_1[palette[i].blue];
- png_composite(w, v, png_ptr->trans[i], back_1.blue);
+ png_composite(w, v, png_ptr->trans_alpha[i], back_1.blue);
palette[i].blue = png_ptr->gamma_from_1[w];
}
}
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
}
}
- /* Prevent the transformations being done again, and make sure
- * that the now spurious alpha channel is stripped - the code
- * has just reduced background composition and gamma correction
- * to a simple alpha channel strip.
- */
- png_ptr->transformations &= ~PNG_BACKGROUND;
- png_ptr->transformations &= ~PNG_GAMMA;
- png_ptr->transformations |= PNG_STRIP_ALPHA;
+ /* Prevent the transformations being done again, and make sure
+ * that the now spurious alpha channel is stripped - the code
+ * has just reduced background composition and gamma correction
+ * to a simple alpha channel strip.
+ */
+ png_ptr->transformations &= ~PNG_BACKGROUND;
+ png_ptr->transformations &= ~PNG_GAMMA;
+ png_ptr->transformations |= PNG_STRIP_ALPHA;
}
/* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
else
g = (png_ptr->screen_gamma);
gs = 1.0;
break;
+
case PNG_BACKGROUND_GAMMA_FILE:
g = 1.0 / (png_ptr->gamma);
gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
break;
+
case PNG_BACKGROUND_GAMMA_UNIQUE:
g = 1.0 / (png_ptr->background_gamma);
gs = 1.0 / (png_ptr->background_gamma *
}
}
else
- /* transformation does not include PNG_BACKGROUND */
+ /* Transformation does not include PNG_BACKGROUND */
#endif /* PNG_READ_BACKGROUND_SUPPORTED */
if (color_type == PNG_COLOR_TYPE_PALETTE)
{
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
}
- /* Done the gamma correction. */
- png_ptr->transformations &= ~PNG_GAMMA;
+ /* Done the gamma correction. */
+ png_ptr->transformations &= ~PNG_GAMMA;
}
}
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
else
#endif
#endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
/* No GAMMA transformation */
if ((png_ptr->transformations & PNG_BACKGROUND) &&
(color_type == PNG_COLOR_TYPE_PALETTE))
for (i = 0; i < istop; i++)
{
- if (png_ptr->trans[i] == 0)
+ if (png_ptr->trans_alpha[i] == 0)
{
palette[i] = back;
}
- else if (png_ptr->trans[i] != 0xff)
+ else if (png_ptr->trans_alpha[i] != 0xff)
{
/* The png_composite() macro is defined in png.h */
png_composite(palette[i].red, palette[i].red,
- png_ptr->trans[i], back.red);
+ png_ptr->trans_alpha[i], back.red);
png_composite(palette[i].green, palette[i].green,
- png_ptr->trans[i], back.green);
+ png_ptr->trans_alpha[i], back.green);
png_composite(palette[i].blue, palette[i].blue,
- png_ptr->trans[i], back.blue);
+ png_ptr->trans_alpha[i], back.blue);
}
}
}
#endif /* PNG_READ_BACKGROUND_SUPPORTED */
-#if defined(PNG_READ_SHIFT_SUPPORTED)
+#ifdef PNG_READ_SHIFT_SUPPORTED
if ((png_ptr->transformations & PNG_SHIFT) &&
(color_type == PNG_COLOR_TYPE_PALETTE))
{
png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
{
png_debug(1, "in png_read_transform_info");
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+
+#ifdef PNG_READ_EXPAND_SUPPORTED
if (png_ptr->transformations & PNG_EXPAND)
{
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (png_ptr->transformations & PNG_EXPAND_tRNS)
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
-#if 0 /* Removed from libpng-1.2.27 */
- else
- info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
-#endif
}
if (info_ptr->bit_depth < 8)
info_ptr->bit_depth = 8;
}
#endif
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
if (png_ptr->transformations & PNG_BACKGROUND)
{
info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
}
#endif
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (png_ptr->transformations & PNG_GAMMA)
{
#ifdef PNG_FLOATING_POINT_SUPPORTED
}
#endif
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
+#ifdef PNG_READ_16_TO_8_SUPPORTED
if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16))
info_ptr->bit_depth = 8;
#endif
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
if (png_ptr->transformations & PNG_GRAY_TO_RGB)
info_ptr->color_type |= PNG_COLOR_MASK_COLOR;
#endif
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
if (png_ptr->transformations & PNG_RGB_TO_GRAY)
info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR;
#endif
-#if defined(PNG_READ_DITHER_SUPPORTED)
- if (png_ptr->transformations & PNG_DITHER)
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if (png_ptr->transformations & PNG_QUANTIZE)
{
if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
- (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
- png_ptr->palette_lookup && info_ptr->bit_depth == 8)
+ (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) &&
+ png_ptr->palette_lookup && info_ptr->bit_depth == 8)
{
info_ptr->color_type = PNG_COLOR_TYPE_PALETTE;
}
}
#endif
-#if defined(PNG_READ_PACK_SUPPORTED)
+#ifdef PNG_READ_PACK_SUPPORTED
if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8))
info_ptr->bit_depth = 8;
#endif
else
info_ptr->channels = 1;
-#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA;
#endif
if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
info_ptr->channels++;
-#if defined(PNG_READ_FILLER_SUPPORTED)
+#ifdef PNG_READ_FILLER_SUPPORTED
/* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */
if ((png_ptr->transformations & PNG_FILLER) &&
((info_ptr->color_type == PNG_COLOR_TYPE_RGB) ||
(info_ptr->color_type == PNG_COLOR_TYPE_GRAY)))
{
info_ptr->channels++;
- /* if adding a true alpha channel not just filler */
-#if !defined(PNG_1_0_X)
+ /* If adding a true alpha channel not just filler */
if (png_ptr->transformations & PNG_ADD_ALPHA)
info_ptr->color_type |= PNG_COLOR_MASK_ALPHA;
-#endif
}
#endif
info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width);
-#if !defined(PNG_READ_EXPAND_SUPPORTED)
+#ifndef PNG_READ_EXPAND_SUPPORTED
if (png_ptr)
return;
#endif
png_do_read_transformations(png_structp png_ptr)
{
png_debug(1, "in png_do_read_transformations");
+
if (png_ptr->row_buf == NULL)
{
-#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
+#ifdef PNG_STDIO_SUPPORTED
char msg[50];
png_snprintf2(msg, 50,
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
/* Application has failed to call either png_read_start_image()
* or png_read_update_info() after setting transforms that expand
- * pixels. This check added to libpng-1.2.19 */
+ * pixels. This check added to libpng-1.2.19
+ */
#if (PNG_WARN_UNINITIALIZED_ROW==1)
png_error(png_ptr, "Uninitialized row");
#else
#endif
#endif
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+#ifdef PNG_READ_EXPAND_SUPPORTED
if (png_ptr->transformations & PNG_EXPAND)
{
if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE)
{
png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->palette, png_ptr->trans, png_ptr->num_trans);
+ png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans);
}
else
{
if (png_ptr->num_trans &&
(png_ptr->transformations & PNG_EXPAND_tRNS))
png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
- &(png_ptr->trans_values));
+ &(png_ptr->trans_color));
else
png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
NULL);
}
#endif
-#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
+#ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)
png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA));
#endif
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
if (png_ptr->transformations & PNG_RGB_TO_GRAY)
{
int rgb_error =
- png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1);
+ png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info),
+ png_ptr->row_buf + 1);
if (rgb_error)
{
png_ptr->rgb_to_gray_status=1;
- if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
+ if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
PNG_RGB_TO_GRAY_WARN)
png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel");
if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
}
#endif
-/*
-From Andreas Dilger e-mail to png-implement, 26 March 1998:
-
- In most cases, the "simple transparency" should be done prior to doing
- gray-to-RGB, or you will have to test 3x as many bytes to check if a
- pixel is transparent. You would also need to make sure that the
- transparency information is upgraded to RGB.
-
- To summarize, the current flow is:
- - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
- with background "in place" if transparent,
- convert to RGB if necessary
- - Gray + alpha -> composite with gray background and remove alpha bytes,
- convert to RGB if necessary
-
- To support RGB backgrounds for gray images we need:
- - Gray + simple transparency -> convert to RGB + simple transparency, compare
- 3 or 6 bytes and composite with background
- "in place" if transparent (3x compare/pixel
- compared to doing composite with gray bkgrnd)
- - Gray + alpha -> convert to RGB + alpha, composite with background and
- remove alpha bytes (3x float operations/pixel
- compared with composite on gray background)
-
- Greg's change will do this. The reason it wasn't done before is for
- performance, as this increases the per-pixel operations. If we would check
- in advance if the background was gray or RGB, and position the gray-to-RGB
- transform appropriately, then it would save a lot of work/time.
+/* From Andreas Dilger e-mail to png-implement, 26 March 1998:
+ *
+ * In most cases, the "simple transparency" should be done prior to doing
+ * gray-to-RGB, or you will have to test 3x as many bytes to check if a
+ * pixel is transparent. You would also need to make sure that the
+ * transparency information is upgraded to RGB.
+ *
+ * To summarize, the current flow is:
+ * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite
+ * with background "in place" if transparent,
+ * convert to RGB if necessary
+ * - Gray + alpha -> composite with gray background and remove alpha bytes,
+ * convert to RGB if necessary
+ *
+ * To support RGB backgrounds for gray images we need:
+ * - Gray + simple transparency -> convert to RGB + simple transparency,
+ * compare 3 or 6 bytes and composite with
+ * background "in place" if transparent
+ * (3x compare/pixel compared to doing
+ * composite with gray bkgrnd)
+ * - Gray + alpha -> convert to RGB + alpha, composite with background and
+ * remove alpha bytes (3x float
+ * operations/pixel compared with composite
+ * on gray background)
+ *
+ * Greg's change will do this. The reason it wasn't done before is for
+ * performance, as this increases the per-pixel operations. If we would check
+ * in advance if the background was gray or RGB, and position the gray-to-RGB
+ * transform appropriately, then it would save a lot of work/time.
*/
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
- /* if gray -> RGB, do so now only if background is non-gray; else do later
- * for performance reasons */
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* If gray -> RGB, do so now only if background is non-gray; else do later
+ * for performance reasons
+ */
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
!(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
if ((png_ptr->transformations & PNG_BACKGROUND) &&
((png_ptr->num_trans != 0 ) ||
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA)))
png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1,
- &(png_ptr->trans_values), &(png_ptr->background)
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+ &(png_ptr->trans_color), &(png_ptr->background)
+#ifdef PNG_READ_GAMMA_SUPPORTED
, &(png_ptr->background_1),
png_ptr->gamma_table, png_ptr->gamma_from_1,
png_ptr->gamma_to_1, png_ptr->gamma_16_table,
);
#endif
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if ((png_ptr->transformations & PNG_GAMMA) &&
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- !((png_ptr->transformations & PNG_BACKGROUND) &&
- ((png_ptr->num_trans != 0) ||
- (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
+ !((png_ptr->transformations & PNG_BACKGROUND) &&
+ ((png_ptr->num_trans != 0) ||
+ (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) &&
#endif
- (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
+ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE))
png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->gamma_table, png_ptr->gamma_16_table,
- png_ptr->gamma_shift);
+ png_ptr->gamma_table, png_ptr->gamma_16_table,
+ png_ptr->gamma_shift);
#endif
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
+#ifdef PNG_READ_16_TO_8_SUPPORTED
if (png_ptr->transformations & PNG_16_TO_8)
png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_DITHER_SUPPORTED)
- if (png_ptr->transformations & PNG_DITHER)
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
+ if (png_ptr->transformations & PNG_QUANTIZE)
{
- png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->palette_lookup, png_ptr->dither_index);
+ png_do_quantize((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1,
+ png_ptr->palette_lookup, png_ptr->quantize_index);
if (png_ptr->row_info.rowbytes == (png_uint_32)0)
- png_error(png_ptr, "png_do_dither returned rowbytes=0");
+ png_error(png_ptr, "png_do_quantize returned rowbytes=0");
}
#endif
-#if defined(PNG_READ_INVERT_SUPPORTED)
+#ifdef PNG_READ_INVERT_SUPPORTED
if (png_ptr->transformations & PNG_INVERT_MONO)
png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_SHIFT_SUPPORTED)
+#ifdef PNG_READ_SHIFT_SUPPORTED
if (png_ptr->transformations & PNG_SHIFT)
png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1,
&(png_ptr->shift));
#endif
-#if defined(PNG_READ_PACK_SUPPORTED)
+#ifdef PNG_READ_PACK_SUPPORTED
if (png_ptr->transformations & PNG_PACK)
png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_BGR_SUPPORTED)
+#ifdef PNG_READ_BGR_SUPPORTED
if (png_ptr->transformations & PNG_BGR)
png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_PACKSWAP_SUPPORTED)
+#ifdef PNG_READ_PACKSWAP_SUPPORTED
if (png_ptr->transformations & PNG_PACKSWAP)
png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
- /* if gray -> RGB, do so now only if we did not do so above */
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+ /* If gray -> RGB, do so now only if we did not do so above */
if ((png_ptr->transformations & PNG_GRAY_TO_RGB) &&
(png_ptr->mode & PNG_BACKGROUND_IS_GRAY))
png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_FILLER_SUPPORTED)
+#ifdef PNG_READ_FILLER_SUPPORTED
if (png_ptr->transformations & PNG_FILLER)
png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
(png_uint_32)png_ptr->filler, png_ptr->flags);
#endif
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
if (png_ptr->transformations & PNG_INVERT_ALPHA)
png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
if (png_ptr->transformations & PNG_SWAP_ALPHA)
png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_SWAP_SUPPORTED)
+#ifdef PNG_READ_SWAP_SUPPORTED
if (png_ptr->transformations & PNG_SWAP_BYTES)
png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
#endif
-#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
+#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED
if (png_ptr->transformations & PNG_USER_TRANSFORM)
{
if (png_ptr->read_user_transform_fn != NULL)
- (*(png_ptr->read_user_transform_fn)) /* user read transform function */
- (png_ptr, /* png_ptr */
- &(png_ptr->row_info), /* row_info: */
- /* png_uint_32 width; width of row */
- /* png_uint_32 rowbytes; number of bytes in row */
- /* png_byte color_type; color type of pixels */
- /* png_byte bit_depth; bit depth of samples */
- /* png_byte channels; number of channels (1-4) */
- /* png_byte pixel_depth; bits per pixel (depth*channels) */
- png_ptr->row_buf + 1); /* start of pixel data for row */
-#if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED)
+ (*(png_ptr->read_user_transform_fn)) /* User read transform function */
+ (png_ptr, /* png_ptr */
+ &(png_ptr->row_info), /* row_info: */
+ /* png_uint_32 width; width of row */
+ /* png_uint_32 rowbytes; number of bytes in row */
+ /* png_byte color_type; color type of pixels */
+ /* png_byte bit_depth; bit depth of samples */
+ /* png_byte channels; number of channels (1-4) */
+ /* png_byte pixel_depth; bits per pixel (depth*channels) */
+ png_ptr->row_buf + 1); /* start of pixel data for row */
+#ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED
if (png_ptr->user_transform_depth)
png_ptr->row_info.bit_depth = png_ptr->user_transform_depth;
if (png_ptr->user_transform_channels)
}
-#if defined(PNG_READ_PACK_SUPPORTED)
+#ifdef PNG_READ_PACK_SUPPORTED
/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel,
* without changing the actual values. Thus, if you had a row with
* a bit depth of 1, you would end up with bytes that only contained
png_do_unpack(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_unpack");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL && row_info->bit_depth < 8)
-#else
+
if (row_info->bit_depth < 8)
-#endif
{
png_uint_32 i;
png_uint_32 row_width=row_info->width;
}
break;
}
+
case 2:
{
}
break;
}
+
case 4:
{
png_bytep sp = row + (png_size_t)((row_width - 1) >> 1);
}
#endif
-#if defined(PNG_READ_SHIFT_SUPPORTED)
+#ifdef PNG_READ_SHIFT_SUPPORTED
/* Reverse the effects of png_do_shift. This routine merely shifts the
* pixels back to their significant bits values. Thus, if you have
* a row of bit depth 8, but only 5 are significant, this will shift
png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits)
{
png_debug(1, "in png_do_unshift");
+
if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL && sig_bits != NULL &&
-#endif
row_info->color_type != PNG_COLOR_TYPE_PALETTE)
{
int shift[4];
}
break;
}
+
case 4:
{
png_bytep bp = row;
}
break;
}
+
case 8:
{
png_bytep bp = row;
}
break;
}
+
case 16:
{
png_bytep bp = row;
}
#endif
-#if defined(PNG_READ_16_TO_8_SUPPORTED)
-/* chop rows of bit depth 16 down to 8 */
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+/* Chop rows of bit depth 16 down to 8 */
void /* PRIVATE */
png_do_chop(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_chop");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL && row_info->bit_depth == 16)
-#else
+
if (row_info->bit_depth == 16)
-#endif
{
png_bytep sp = row;
png_bytep dp = row;
for (i = 0; i<istop; i++, sp += 2, dp++)
{
-#if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED)
+#ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
/* This does a more accurate scaling of the 16-bit color
* value, rather than a simple low-byte truncation.
*
* What the ideal calculation should be:
* *dp = (((((png_uint_32)(*sp) << 8) |
- * (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L;
+ * (png_uint_32)(*(sp + 1))) * 255 + 127)
+ * / (png_uint_32)65535L;
*
* GRR: no, I think this is what it really should be:
* *dp = (((((png_uint_32)(*sp) << 8) |
- * (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L;
+ * (png_uint_32)(*(sp + 1))) + 128L)
+ * / (png_uint_32)257L;
*
* GRR: here's the exact calculation with shifts:
- * temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L;
+ * temp = (((png_uint_32)(*sp) << 8) |
+ * (png_uint_32)(*(sp + 1))) + 128L;
* *dp = (temp - (temp >> 8)) >> 8;
*
* Approximate calculation with shift/add instead of multiply/divide:
}
#endif
-#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED)
+#ifdef PNG_READ_SWAP_ALPHA_SUPPORTED
void /* PRIVATE */
png_do_read_swap_alpha(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_swap_alpha");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
+
{
png_uint_32 row_width = row_info->width;
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
}
#endif
-#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED)
+#ifdef PNG_READ_INVERT_ALPHA_SUPPORTED
void /* PRIVATE */
png_do_read_invert_alpha(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_invert_alpha");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
+
{
png_uint_32 row_width = row_info->width;
if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
}
#endif
-#if defined(PNG_READ_FILLER_SUPPORTED)
+#ifdef PNG_READ_FILLER_SUPPORTED
/* Add filler channel if we have RGB color */
void /* PRIVATE */
png_do_read_filler(png_row_infop row_info, png_bytep row,
png_byte lo_filler = (png_byte)(filler & 0xff);
png_debug(1, "in png_do_read_filler");
+
if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
row_info->color_type == PNG_COLOR_TYPE_GRAY)
{
if (row_info->bit_depth == 8)
}
#endif
-#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
-/* expand grayscale files to RGB, with or without alpha */
+#ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
+/* Expand grayscale files to RGB, with or without alpha */
void /* PRIVATE */
png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
{
png_uint_32 row_width = row_info->width;
png_debug(1, "in png_do_gray_to_rgb");
+
if (row_info->bit_depth >= 8 &&
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
!(row_info->color_type & PNG_COLOR_MASK_COLOR))
{
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
}
#endif
-#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
-/* reduce RGB files to grayscale, with or without alpha
+#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED
+/* Reduce RGB files to grayscale, with or without alpha
* using the equation given in Poynton's ColorFAQ at
* <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008)
* New link:
int rgb_error = 0;
png_debug(1, "in png_do_rgb_to_gray");
+
if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
(row_info->color_type & PNG_COLOR_MASK_COLOR))
{
png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
{
png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
png_ptr->gamma_shift][red>>8];
- png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
+ png_uint_16 green_1 =
+ png_ptr->gamma_16_to_1[(green&0xff) >>
png_ptr->gamma_shift][green>>8];
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
png_ptr->gamma_shift][blue>>8];
else
{
png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >>
- png_ptr->gamma_shift][red>>8];
- png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >>
- png_ptr->gamma_shift][green>>8];
+ png_ptr->gamma_shift][red>>8];
+ png_uint_16 green_1 =
+ png_ptr->gamma_16_to_1[(green&0xff) >>
+ png_ptr->gamma_shift][green>>8];
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
- png_ptr->gamma_shift][blue>>8];
+ png_ptr->gamma_shift][blue>>8];
png_uint_16 gray16 = (png_uint_16)((rc * red_1
- + gc * green_1 + bc * blue_1)>>15);
+ + gc * green_1 + bc * blue_1)>>15);
w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
png_ptr->gamma_shift][gray16 >> 8];
rgb_error |= 1;
int v;
png_debug(1, "in png_do_build_grayscale_palette");
+
if (palette == NULL)
return;
num_palette = 2;
color_inc = 0xff;
break;
+
case 2:
num_palette = 4;
color_inc = 0x55;
break;
+
case 4:
num_palette = 16;
color_inc = 0x11;
break;
+
case 8:
num_palette = 256;
color_inc = 1;
break;
+
default:
num_palette = 0;
color_inc = 0;
}
}
-/* This function is currently unused. Do we really need it? */
-#if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED)
-void /* PRIVATE */
-png_correct_palette(png_structp png_ptr, png_colorp palette,
- int num_palette)
-{
- png_debug(1, "in png_correct_palette");
-#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
- defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
- if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND))
- {
- png_color back, back_1;
-
- if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE)
- {
- back.red = png_ptr->gamma_table[png_ptr->background.red];
- back.green = png_ptr->gamma_table[png_ptr->background.green];
- back.blue = png_ptr->gamma_table[png_ptr->background.blue];
-
- back_1.red = png_ptr->gamma_to_1[png_ptr->background.red];
- back_1.green = png_ptr->gamma_to_1[png_ptr->background.green];
- back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue];
- }
- else
- {
- double g;
-
- g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma);
- if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN ||
- fabs(g - 1.0) < PNG_GAMMA_THRESHOLD)
- {
- back.red = png_ptr->background.red;
- back.green = png_ptr->background.green;
- back.blue = png_ptr->background.blue;
- }
- else
- {
- back.red =
- (png_byte)(pow((double)png_ptr->background.red/255, g) *
- 255.0 + 0.5);
- back.green =
- (png_byte)(pow((double)png_ptr->background.green/255, g) *
- 255.0 + 0.5);
- back.blue =
- (png_byte)(pow((double)png_ptr->background.blue/255, g) *
- 255.0 + 0.5);
- }
-
- g = 1.0 / png_ptr->background_gamma;
-
- back_1.red =
- (png_byte)(pow((double)png_ptr->background.red/255, g) *
- 255.0 + 0.5);
- back_1.green =
- (png_byte)(pow((double)png_ptr->background.green/255, g) *
- 255.0 + 0.5);
- back_1.blue =
- (png_byte)(pow((double)png_ptr->background.blue/255, g) *
- 255.0 + 0.5);
- }
-
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_uint_32 i;
-
- for (i = 0; i < (png_uint_32)num_palette; i++)
- {
- if (i < png_ptr->num_trans && png_ptr->trans[i] == 0)
- {
- palette[i] = back;
- }
- else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff)
- {
- png_byte v, w;
-
- v = png_ptr->gamma_to_1[png_ptr->palette[i].red];
- png_composite(w, v, png_ptr->trans[i], back_1.red);
- palette[i].red = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[png_ptr->palette[i].green];
- png_composite(w, v, png_ptr->trans[i], back_1.green);
- palette[i].green = png_ptr->gamma_from_1[w];
-
- v = png_ptr->gamma_to_1[png_ptr->palette[i].blue];
- png_composite(w, v, png_ptr->trans[i], back_1.blue);
- palette[i].blue = png_ptr->gamma_from_1[w];
- }
- else
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
- }
- else
- {
- int i;
-
- for (i = 0; i < num_palette; i++)
- {
- if (palette[i].red == (png_byte)png_ptr->trans_values.gray)
- {
- palette[i] = back;
- }
- else
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
- }
- }
- else
-#endif
-#if defined(PNG_READ_GAMMA_SUPPORTED)
- if (png_ptr->transformations & PNG_GAMMA)
- {
- int i;
-
- for (i = 0; i < num_palette; i++)
- {
- palette[i].red = png_ptr->gamma_table[palette[i].red];
- palette[i].green = png_ptr->gamma_table[palette[i].green];
- palette[i].blue = png_ptr->gamma_table[palette[i].blue];
- }
- }
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- else
-#endif
-#endif
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
- if (png_ptr->transformations & PNG_BACKGROUND)
- {
- if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
- {
- png_color back;
-
- back.red = (png_byte)png_ptr->background.red;
- back.green = (png_byte)png_ptr->background.green;
- back.blue = (png_byte)png_ptr->background.blue;
-
- for (i = 0; i < (int)png_ptr->num_trans; i++)
- {
- if (png_ptr->trans[i] == 0)
- {
- palette[i].red = back.red;
- palette[i].green = back.green;
- palette[i].blue = back.blue;
- }
- else if (png_ptr->trans[i] != 0xff)
- {
- png_composite(palette[i].red, png_ptr->palette[i].red,
- png_ptr->trans[i], back.red);
- png_composite(palette[i].green, png_ptr->palette[i].green,
- png_ptr->trans[i], back.green);
- png_composite(palette[i].blue, png_ptr->palette[i].blue,
- png_ptr->trans[i], back.blue);
- }
- }
- }
- else /* assume grayscale palette (what else could it be?) */
- {
- int i;
-
- for (i = 0; i < num_palette; i++)
- {
- if (i == (png_byte)png_ptr->trans_values.gray)
- {
- palette[i].red = (png_byte)png_ptr->background.red;
- palette[i].green = (png_byte)png_ptr->background.green;
- palette[i].blue = (png_byte)png_ptr->background.blue;
- }
- }
- }
- }
-#endif
-}
-#endif
-
-#if defined(PNG_READ_BACKGROUND_SUPPORTED)
+#ifdef PNG_READ_BACKGROUND_SUPPORTED
/* Replace any alpha or transparency with the supplied background color.
* "background" is already in the screen gamma, while "background_1" is
* at a gamma of 1.0. Paletted files have already been taken care of.
*/
void /* PRIVATE */
png_do_background(png_row_infop row_info, png_bytep row,
- png_color_16p trans_values, png_color_16p background
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+ png_color_16p trans_color, png_color_16p background
+#ifdef PNG_READ_GAMMA_SUPPORTED
, png_color_16p background_1,
png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1,
png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1,
int shift;
png_debug(1, "in png_do_background");
+
if (background != NULL &&
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
(!(row_info->color_type & PNG_COLOR_MASK_ALPHA) ||
- (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values)))
+ (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_color)))
{
switch (row_info->color_type)
{
for (i = 0; i < row_width; i++)
{
if ((png_uint_16)((*sp >> shift) & 0x01)
- == trans_values->gray)
+ == trans_color->gray)
{
*sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff);
*sp |= (png_byte)(background->gray << shift);
}
break;
}
+
case 2:
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_table != NULL)
{
sp = row;
for (i = 0; i < row_width; i++)
{
if ((png_uint_16)((*sp >> shift) & 0x03)
- == trans_values->gray)
+ == trans_color->gray)
{
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
*sp |= (png_byte)(background->gray << shift);
for (i = 0; i < row_width; i++)
{
if ((png_uint_16)((*sp >> shift) & 0x03)
- == trans_values->gray)
+ == trans_color->gray)
{
*sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff);
*sp |= (png_byte)(background->gray << shift);
}
break;
}
+
case 4:
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_table != NULL)
{
sp = row;
for (i = 0; i < row_width; i++)
{
if ((png_uint_16)((*sp >> shift) & 0x0f)
- == trans_values->gray)
+ == trans_color->gray)
{
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
*sp |= (png_byte)(background->gray << shift);
for (i = 0; i < row_width; i++)
{
if ((png_uint_16)((*sp >> shift) & 0x0f)
- == trans_values->gray)
+ == trans_color->gray)
{
*sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff);
*sp |= (png_byte)(background->gray << shift);
}
break;
}
+
case 8:
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_table != NULL)
{
sp = row;
for (i = 0; i < row_width; i++, sp++)
{
- if (*sp == trans_values->gray)
+ if (*sp == trans_color->gray)
{
*sp = (png_byte)background->gray;
}
sp = row;
for (i = 0; i < row_width; i++, sp++)
{
- if (*sp == trans_values->gray)
+ if (*sp == trans_color->gray)
{
*sp = (png_byte)background->gray;
}
}
break;
}
+
case 16:
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_16 != NULL)
{
sp = row;
png_uint_16 v;
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- if (v == trans_values->gray)
+ if (v == trans_color->gray)
{
- /* background is already in screen gamma */
+ /* Background is already in screen gamma */
*sp = (png_byte)((background->gray >> 8) & 0xff);
*(sp + 1) = (png_byte)(background->gray & 0xff);
}
png_uint_16 v;
v = (png_uint_16)(((*sp) << 8) + *(sp + 1));
- if (v == trans_values->gray)
+ if (v == trans_color->gray)
{
*sp = (png_byte)((background->gray >> 8) & 0xff);
*(sp + 1) = (png_byte)(background->gray & 0xff);
}
break;
}
+
case PNG_COLOR_TYPE_RGB:
{
if (row_info->bit_depth == 8)
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_table != NULL)
{
sp = row;
for (i = 0; i < row_width; i++, sp += 3)
{
- if (*sp == trans_values->red &&
- *(sp + 1) == trans_values->green &&
- *(sp + 2) == trans_values->blue)
+ if (*sp == trans_color->red &&
+ *(sp + 1) == trans_color->green &&
+ *(sp + 2) == trans_color->blue)
{
*sp = (png_byte)background->red;
*(sp + 1) = (png_byte)background->green;
sp = row;
for (i = 0; i < row_width; i++, sp += 3)
{
- if (*sp == trans_values->red &&
- *(sp + 1) == trans_values->green &&
- *(sp + 2) == trans_values->blue)
+ if (*sp == trans_color->red &&
+ *(sp + 1) == trans_color->green &&
+ *(sp + 2) == trans_color->blue)
{
*sp = (png_byte)background->red;
*(sp + 1) = (png_byte)background->green;
}
else /* if (row_info->bit_depth == 16) */
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_16 != NULL)
{
sp = row;
png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1));
png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
- if (r == trans_values->red && g == trans_values->green &&
- b == trans_values->blue)
+ if (r == trans_color->red && g == trans_color->green &&
+ b == trans_color->blue)
{
- /* background is already in screen gamma */
+ /* Background is already in screen gamma */
*sp = (png_byte)((background->red >> 8) & 0xff);
*(sp + 1) = (png_byte)(background->red & 0xff);
*(sp + 2) = (png_byte)((background->green >> 8) & 0xff);
png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3));
png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5));
- if (r == trans_values->red && g == trans_values->green &&
- b == trans_values->blue)
+ if (r == trans_color->red && g == trans_color->green &&
+ b == trans_color->blue)
{
*sp = (png_byte)((background->red >> 8) & 0xff);
*(sp + 1) = (png_byte)(background->red & 0xff);
}
break;
}
+
case PNG_COLOR_TYPE_GRAY_ALPHA:
{
if (row_info->bit_depth == 8)
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
gamma_table != NULL)
{
}
else if (a == 0)
{
- /* background is already in screen gamma */
+ /* Background is already in screen gamma */
*dp = (png_byte)background->gray;
}
else
{
*dp = *sp;
}
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
else if (a == 0)
{
*dp = (png_byte)background->gray;
}
else /* if (png_ptr->bit_depth == 16) */
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
gamma_16_to_1 != NULL)
{
*dp = (png_byte)((v >> 8) & 0xff);
*(dp + 1) = (png_byte)(v & 0xff);
}
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
else if (a == 0)
#else
else
#endif
{
- /* background is already in screen gamma */
+ /* Background is already in screen gamma */
*dp = (png_byte)((background->gray >> 8) & 0xff);
*(dp + 1) = (png_byte)(background->gray & 0xff);
}
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
else
{
png_uint_16 g, v, w;
{
png_memcpy(dp, sp, 2);
}
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
else if (a == 0)
#else
else
*dp = (png_byte)((background->gray >> 8) & 0xff);
*(dp + 1) = (png_byte)(background->gray & 0xff);
}
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
else
{
png_uint_16 g, v;
}
break;
}
+
case PNG_COLOR_TYPE_RGB_ALPHA:
{
if (row_info->bit_depth == 8)
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_to_1 != NULL && gamma_from_1 != NULL &&
gamma_table != NULL)
{
}
else if (a == 0)
{
- /* background is already in screen gamma */
+ /* Background is already in screen gamma */
*dp = (png_byte)background->red;
*(dp + 1) = (png_byte)background->green;
*(dp + 2) = (png_byte)background->blue;
}
else /* if (row_info->bit_depth == 16) */
{
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
if (gamma_16 != NULL && gamma_16_from_1 != NULL &&
gamma_16_to_1 != NULL)
{
}
else if (a == 0)
{
- /* background is already in screen gamma */
+ /* Background is already in screen gamma */
*dp = (png_byte)((background->red >> 8) & 0xff);
*(dp + 1) = (png_byte)(background->red & 0xff);
*(dp + 2) = (png_byte)((background->green >> 8) & 0xff);
}
#endif
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
/* Gamma correct the image, avoiding the alpha channel. Make sure
* you do this after you deal with the transparency issue on grayscale
* or RGB images. If your bit depth is 8, use gamma_table, if it
png_uint_32 row_width=row_info->width;
png_debug(1, "in png_do_gamma");
+
if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
((row_info->bit_depth <= 8 && gamma_table != NULL) ||
(row_info->bit_depth == 16 && gamma_16_table != NULL)))
{
}
break;
}
+
case PNG_COLOR_TYPE_RGB_ALPHA:
{
if (row_info->bit_depth == 8)
}
break;
}
+
case PNG_COLOR_TYPE_GRAY_ALPHA:
{
if (row_info->bit_depth == 8)
}
break;
}
+
case PNG_COLOR_TYPE_GRAY:
{
if (row_info->bit_depth == 2)
int d = *sp & 0x03;
*sp = (png_byte)(
- ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
- ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
- ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
- ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
+ ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)|
+ ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)|
+ ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)|
+ ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ));
sp++;
}
}
+
if (row_info->bit_depth == 4)
{
sp = row;
int lsb = *sp & 0x0f;
*sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0)
- | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
+ | (((int)gamma_table[(lsb << 4) | lsb]) >> 4));
sp++;
}
}
+
else if (row_info->bit_depth == 8)
{
sp = row;
sp++;
}
}
+
else if (row_info->bit_depth == 16)
{
sp = row;
}
#endif
-#if defined(PNG_READ_EXPAND_SUPPORTED)
+#ifdef PNG_READ_EXPAND_SUPPORTED
/* Expands a palette row to an RGB or RGBA row depending
* upon whether you supply trans and num_trans.
*/
void /* PRIVATE */
png_do_expand_palette(png_row_infop row_info, png_bytep row,
- png_colorp palette, png_bytep trans, int num_trans)
+ png_colorp palette, png_bytep trans_alpha, int num_trans)
{
int shift, value;
png_bytep sp, dp;
png_uint_32 row_width=row_info->width;
png_debug(1, "in png_do_expand_palette");
+
if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
row_info->color_type == PNG_COLOR_TYPE_PALETTE)
{
if (row_info->bit_depth < 8)
}
break;
}
+
case 2:
{
sp = row + (png_size_t)((row_width - 1) >> 2);
}
break;
}
+
case 4:
{
sp = row + (png_size_t)((row_width - 1) >> 1);
{
case 8:
{
- if (trans != NULL)
+ if (trans_alpha != NULL)
{
sp = row + (png_size_t)row_width - 1;
dp = row + (png_size_t)(row_width << 2) - 1;
if ((int)(*sp) >= num_trans)
*dp-- = 0xff;
else
- *dp-- = trans[*sp];
+ *dp-- = trans_alpha[*sp];
*dp-- = palette[*sp].blue;
*dp-- = palette[*sp].green;
*dp-- = palette[*sp].red;
*dp-- = palette[*sp].red;
sp--;
}
+
row_info->bit_depth = 8;
row_info->pixel_depth = 24;
row_info->rowbytes = row_width * 3;
png_uint_32 row_width=row_info->width;
png_debug(1, "in png_do_expand");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
+
{
if (row_info->color_type == PNG_COLOR_TYPE_GRAY)
{
}
break;
}
+
case 2:
{
gray = (png_uint_16)((gray&0x03)*0x55);
}
break;
}
+
case 4:
{
gray = (png_uint_16)((gray&0x0f)*0x11);
break;
}
}
+
row_info->bit_depth = 8;
row_info->pixel_depth = 8;
row_info->rowbytes = row_width;
*dp-- = *sp--;
}
}
+
else if (row_info->bit_depth == 16)
{
png_byte gray_high = (gray >> 8) & 0xff;
dp = row + (row_info->rowbytes << 1) - 1;
for (i = 0; i < row_width; i++)
{
- if (*(sp - 1) == gray_high && *(sp) == gray_low)
+ if (*(sp - 1) == gray_high && *(sp) == gray_low)
{
*dp-- = 0;
*dp-- = 0;
*dp-- = *sp--;
}
}
+
row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
row_info->channels = 2;
row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1);
}
#endif
-#if defined(PNG_READ_DITHER_SUPPORTED)
+#ifdef PNG_READ_QUANTIZE_SUPPORTED
void /* PRIVATE */
-png_do_dither(png_row_infop row_info, png_bytep row,
- png_bytep palette_lookup, png_bytep dither_lookup)
+png_do_quantize(png_row_infop row_info, png_bytep row,
+ png_bytep palette_lookup, png_bytep quantize_lookup)
{
png_bytep sp, dp;
png_uint_32 i;
png_uint_32 row_width=row_info->width;
- png_debug(1, "in png_do_dither");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
+ png_debug(1, "in png_do_quantize");
+
{
if (row_info->color_type == PNG_COLOR_TYPE_RGB &&
palette_lookup && row_info->bit_depth == 8)
g = *sp++;
b = *sp++;
- /* this looks real messy, but the compiler will reduce
- it down to a reasonable formula. For example, with
- 5 bits per color, we get:
- p = (((r >> 3) & 0x1f) << 10) |
- (((g >> 3) & 0x1f) << 5) |
- ((b >> 3) & 0x1f);
- */
- p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
- ((1 << PNG_DITHER_RED_BITS) - 1)) <<
- (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
- (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
- ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
- (PNG_DITHER_BLUE_BITS)) |
- ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
- ((1 << PNG_DITHER_BLUE_BITS) - 1));
+ /* This looks real messy, but the compiler will reduce
+ * it down to a reasonable formula. For example, with
+ * 5 bits per color, we get:
+ * p = (((r >> 3) & 0x1f) << 10) |
+ * (((g >> 3) & 0x1f) << 5) |
+ * ((b >> 3) & 0x1f);
+ */
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
*dp++ = palette_lookup[p];
}
b = *sp++;
sp++;
- p = (((r >> (8 - PNG_DITHER_RED_BITS)) &
- ((1 << PNG_DITHER_RED_BITS) - 1)) <<
- (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) |
- (((g >> (8 - PNG_DITHER_GREEN_BITS)) &
- ((1 << PNG_DITHER_GREEN_BITS) - 1)) <<
- (PNG_DITHER_BLUE_BITS)) |
- ((b >> (8 - PNG_DITHER_BLUE_BITS)) &
- ((1 << PNG_DITHER_BLUE_BITS) - 1));
+ p = (((r >> (8 - PNG_QUANTIZE_RED_BITS)) &
+ ((1 << PNG_QUANTIZE_RED_BITS) - 1)) <<
+ (PNG_QUANTIZE_GREEN_BITS + PNG_QUANTIZE_BLUE_BITS)) |
+ (((g >> (8 - PNG_QUANTIZE_GREEN_BITS)) &
+ ((1 << PNG_QUANTIZE_GREEN_BITS) - 1)) <<
+ (PNG_QUANTIZE_BLUE_BITS)) |
+ ((b >> (8 - PNG_QUANTIZE_BLUE_BITS)) &
+ ((1 << PNG_QUANTIZE_BLUE_BITS) - 1));
*dp++ = palette_lookup[p];
}
row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width);
}
else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE &&
- dither_lookup && row_info->bit_depth == 8)
+ quantize_lookup && row_info->bit_depth == 8)
{
sp = row;
for (i = 0; i < row_width; i++, sp++)
{
- *sp = dither_lookup[*sp];
+ *sp = quantize_lookup[*sp];
}
}
}
#endif
#ifdef PNG_FLOATING_POINT_SUPPORTED
-#if defined(PNG_READ_GAMMA_SUPPORTED)
+#ifdef PNG_READ_GAMMA_SUPPORTED
static PNG_CONST int png_gamma_shift[] =
{0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
* tables, we don't make a full table if we are reducing to 8-bit in
* the future. Note also how the gamma_16 tables are segmented so that
* we don't need to allocate > 64K chunks for a full 16-bit table.
+ *
+ * See the PNG extensions document for an integer algorithm for creating
+ * the gamma tables. Maybe we will implement that here someday.
+ *
+ * We should only reach this point if
+ *
+ * the file_gamma is known (i.e., the gAMA or sRGB chunk is present,
+ * or the application has provided a file_gamma)
+ *
+ * AND
+ * {
+ * the screen_gamma is known
+ *
+ * OR
+ *
+ * RGB_to_gray transformation is being performed
+ * }
+ *
+ * AND
+ * {
+ * the screen_gamma is different from the reciprocal of the
+ * file_gamma by more than the specified threshold
+ *
+ * OR
+ *
+ * a background color has been specified and the file_gamma
+ * and screen_gamma are not 1.0, within the specified threshold.
+ * }
*/
+
void /* PRIVATE */
-png_build_gamma_table(png_structp png_ptr)
+png_build_gamma_table(png_structp png_ptr, png_byte bit_depth)
{
png_debug(1, "in png_build_gamma_table");
- if (png_ptr->bit_depth <= 8)
+ if (bit_depth <= 8)
{
int i;
double g;
if (png_ptr->screen_gamma > .000001)
g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma);
+
else
g = 1.0;
if (png_ptr->screen_gamma > 0.000001)
g = 1.0 / png_ptr->screen_gamma;
+
else
- g = png_ptr->gamma; /* probably doing rgb_to_gray */
+ g = png_ptr->gamma; /* Probably doing rgb_to_gray */
for (i = 0; i < 256; i++)
{
if (png_ptr->color_type & PNG_COLOR_MASK_COLOR)
{
sig_bit = (int)png_ptr->sig_bit.red;
+
if ((int)png_ptr->sig_bit.green > sig_bit)
sig_bit = png_ptr->sig_bit.green;
+
if ((int)png_ptr->sig_bit.blue > sig_bit)
sig_bit = png_ptr->sig_bit.blue;
}
if (sig_bit > 0)
shift = 16 - sig_bit;
+
else
shift = 0;
if (shift > 8)
shift = 8;
+
if (shift < 0)
shift = 0;
else
g = 1.0;
- png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr,
+ png_ptr->gamma_16_table = (png_uint_16pp)png_calloc(png_ptr,
(png_uint_32)(num * png_sizeof(png_uint_16p)));
if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND))
(png_uint_32)(256 * png_sizeof(png_uint_16)));
ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4);
+
for (j = 0; j < 256; j++)
{
png_ptr->gamma_16_table[i][j] =
g = 1.0 / (png_ptr->gamma);
- png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr,
+ png_ptr->gamma_16_to_1 = (png_uint_16pp)png_calloc(png_ptr,
(png_uint_32)(num * png_sizeof(png_uint_16p )));
for (i = 0; i < num; i++)
if (png_ptr->screen_gamma > 0.000001)
g = 1.0 / png_ptr->screen_gamma;
+
else
- g = png_ptr->gamma; /* probably doing rgb_to_gray */
+ g = png_ptr->gamma; /* Probably doing rgb_to_gray */
- png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr,
+ png_ptr->gamma_16_from_1 = (png_uint_16pp)png_calloc(png_ptr,
(png_uint_32)(num * png_sizeof(png_uint_16p)));
for (i = 0; i < num; i++)
ig = (((png_uint_32)i *
(png_uint_32)png_gamma_shift[shift]) >> 4);
+
for (j = 0; j < 256; j++)
{
png_ptr->gamma_16_from_1[i][j] =
/* To do: install integer version of png_build_gamma_table here */
#endif
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
-/* undoes intrapixel differencing */
+#ifdef PNG_MNG_FEATURES_SUPPORTED
+/* Undoes intrapixel differencing */
void /* PRIVATE */
png_do_read_intrapixel(png_row_infop row_info, png_bytep row)
{
png_debug(1, "in png_do_read_intrapixel");
+
if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
(row_info->color_type & PNG_COLOR_MASK_COLOR))
{
int bytes_per_pixel;
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
bytes_per_pixel = 3;
+
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
bytes_per_pixel = 4;
+
else
return;
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
bytes_per_pixel = 6;
+
else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
bytes_per_pixel = 8;
+
else
return;
projects / wxWidgets.git / blobdiff