mirror of
https://git.code.sf.net/p/libpng/code.git
synced 2025-07-10 18:04:09 +02:00
Imported from pngcrush-1.6.5.tar
This commit is contained in:
Glenn Randers-Pehrson
149
pngrtran.c
149
pngrtran.c
@@ -1,9 +1,9 @@
|
||||
|
||||
/* pngrtran.c - transforms the data in a row for PNG readers
|
||||
*
|
||||
* Last changed in libpng 1.2.9 April 14, 2006
|
||||
* Last changed in libpng 1.2.27 [April 29, 2008]
|
||||
* For conditions of distribution and use, see copyright notice in png.h
|
||||
* Copyright (c) 1998-2006 Glenn Randers-Pehrson
|
||||
* Copyright (c) 1998-2008 Glenn Randers-Pehrson
|
||||
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
|
||||
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
|
||||
*
|
||||
@@ -24,6 +24,7 @@ png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action)
|
||||
{
|
||||
png_debug(1, "in png_set_crc_action\n");
|
||||
/* Tell libpng how we react to CRC errors in critical chunks */
|
||||
if(png_ptr == NULL) return;
|
||||
switch (crit_action)
|
||||
{
|
||||
case PNG_CRC_NO_CHANGE: /* leave setting as is */
|
||||
@@ -80,6 +81,7 @@ png_set_background(png_structp png_ptr,
|
||||
int need_expand, double background_gamma)
|
||||
{
|
||||
png_debug(1, "in png_set_background\n");
|
||||
if(png_ptr == NULL) return;
|
||||
if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN)
|
||||
{
|
||||
png_warning(png_ptr, "Application must supply a known background gamma");
|
||||
@@ -92,17 +94,6 @@ png_set_background(png_structp png_ptr,
|
||||
png_ptr->background_gamma = (float)background_gamma;
|
||||
png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
|
||||
png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0);
|
||||
|
||||
/* Note: if need_expand is set and color_type is either RGB or RGB_ALPHA
|
||||
* (in which case need_expand is superfluous anyway), the background color
|
||||
* might actually be gray yet not be flagged as such. This is not a problem
|
||||
* for the current code, which uses PNG_BACKGROUND_IS_GRAY only to
|
||||
* decide when to do the png_do_gray_to_rgb() transformation.
|
||||
*/
|
||||
if ((need_expand && !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) ||
|
||||
(!need_expand && background_color->red == background_color->green &&
|
||||
background_color->red == background_color->blue))
|
||||
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
||||
}
|
||||
#endif
|
||||
|
||||
@@ -112,6 +103,7 @@ void PNGAPI
|
||||
png_set_strip_16(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_strip_16\n");
|
||||
if(png_ptr == NULL) return;
|
||||
png_ptr->transformations |= PNG_16_TO_8;
|
||||
}
|
||||
#endif
|
||||
@@ -121,6 +113,7 @@ void PNGAPI
|
||||
png_set_strip_alpha(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_strip_alpha\n");
|
||||
if(png_ptr == NULL) return;
|
||||
png_ptr->flags |= PNG_FLAG_STRIP_ALPHA;
|
||||
}
|
||||
#endif
|
||||
@@ -150,6 +143,7 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
|
||||
int full_dither)
|
||||
{
|
||||
png_debug(1, "in png_set_dither\n");
|
||||
if(png_ptr == NULL) return;
|
||||
png_ptr->transformations |= PNG_DITHER;
|
||||
|
||||
if (!full_dither)
|
||||
@@ -533,6 +527,7 @@ void PNGAPI
|
||||
png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
|
||||
{
|
||||
png_debug(1, "in png_set_gamma\n");
|
||||
if(png_ptr == NULL) return;
|
||||
if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
|
||||
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
|
||||
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
|
||||
@@ -551,7 +546,9 @@ void PNGAPI
|
||||
png_set_expand(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_expand\n");
|
||||
if(png_ptr == NULL) return;
|
||||
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
||||
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
||||
}
|
||||
|
||||
/* GRR 19990627: the following three functions currently are identical
|
||||
@@ -576,7 +573,9 @@ void PNGAPI
|
||||
png_set_palette_to_rgb(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_palette_to_rgb\n");
|
||||
if(png_ptr == NULL) return;
|
||||
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
||||
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
||||
}
|
||||
|
||||
#if !defined(PNG_1_0_X)
|
||||
@@ -585,7 +584,9 @@ void PNGAPI
|
||||
png_set_expand_gray_1_2_4_to_8(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_expand_gray_1_2_4_to_8\n");
|
||||
png_ptr->transformations |= PNG_EXPAND_tRNS;
|
||||
if(png_ptr == NULL) return;
|
||||
png_ptr->transformations |= PNG_EXPAND;
|
||||
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
||||
}
|
||||
#endif
|
||||
|
||||
@@ -596,6 +597,7 @@ void PNGAPI
|
||||
png_set_gray_1_2_4_to_8(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_gray_1_2_4_to_8\n");
|
||||
if(png_ptr == NULL) return;
|
||||
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
||||
}
|
||||
#endif
|
||||
@@ -605,8 +607,9 @@ png_set_gray_1_2_4_to_8(png_structp png_ptr)
|
||||
void PNGAPI
|
||||
png_set_tRNS_to_alpha(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_expand\n");
|
||||
png_debug(1, "in png_set_tRNS_to_alpha\n");
|
||||
png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS);
|
||||
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
||||
}
|
||||
#endif /* defined(PNG_READ_EXPAND_SUPPORTED) */
|
||||
|
||||
@@ -616,6 +619,7 @@ png_set_gray_to_rgb(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_set_gray_to_rgb\n");
|
||||
png_ptr->transformations |= PNG_GRAY_TO_RGB;
|
||||
png_ptr->flags &= ~PNG_FLAG_ROW_INIT;
|
||||
}
|
||||
#endif
|
||||
|
||||
@@ -631,6 +635,7 @@ png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
|
||||
{
|
||||
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
|
||||
@@ -640,6 +645,7 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action,
|
||||
png_fixed_point red, png_fixed_point green)
|
||||
{
|
||||
png_debug(1, "in png_set_rgb_to_gray\n");
|
||||
if(png_ptr == NULL) return;
|
||||
switch(error_action)
|
||||
{
|
||||
case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY;
|
||||
@@ -690,6 +696,7 @@ png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr
|
||||
read_user_transform_fn)
|
||||
{
|
||||
png_debug(1, "in png_set_read_user_transform_fn\n");
|
||||
if(png_ptr == NULL) return;
|
||||
#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED)
|
||||
png_ptr->transformations |= PNG_USER_TRANSFORM;
|
||||
png_ptr->read_user_transform_fn = read_user_transform_fn;
|
||||
@@ -719,6 +726,32 @@ png_init_read_transformations(png_structp png_ptr)
|
||||
#endif
|
||||
|
||||
#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED)
|
||||
|
||||
#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED)
|
||||
/* Detect gray background and attempt to enable optimization
|
||||
* for gray --> RGB case */
|
||||
/* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or
|
||||
* RGB_ALPHA (in which case need_expand is superfluous anyway), the
|
||||
* background color might actually be gray yet not be flagged as such.
|
||||
* This is not a problem for the current code, which uses
|
||||
* PNG_BACKGROUND_IS_GRAY only to decide when to do the
|
||||
* png_do_gray_to_rgb() transformation.
|
||||
*/
|
||||
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
|
||||
!(color_type & PNG_COLOR_MASK_COLOR))
|
||||
{
|
||||
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
||||
} else if ((png_ptr->transformations & PNG_BACKGROUND) &&
|
||||
!(png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
|
||||
(png_ptr->transformations & PNG_GRAY_TO_RGB) &&
|
||||
png_ptr->background.red == png_ptr->background.green &&
|
||||
png_ptr->background.red == png_ptr->background.blue)
|
||||
{
|
||||
png_ptr->mode |= PNG_BACKGROUND_IS_GRAY;
|
||||
png_ptr->background.gray = png_ptr->background.red;
|
||||
}
|
||||
#endif
|
||||
|
||||
if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) &&
|
||||
(png_ptr->transformations & PNG_EXPAND))
|
||||
{
|
||||
@@ -814,7 +847,7 @@ png_init_read_transformations(png_structp png_ptr)
|
||||
k=1; /* partial transparency is present */
|
||||
}
|
||||
if (k == 0)
|
||||
png_ptr->transformations &= (~PNG_GAMMA);
|
||||
png_ptr->transformations &= ~PNG_GAMMA;
|
||||
}
|
||||
|
||||
if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) &&
|
||||
@@ -921,6 +954,14 @@ png_init_read_transformations(png_structp png_ptr)
|
||||
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
||||
}
|
||||
}
|
||||
/* Prevent the transformations being done again, and make sure
|
||||
* that the now spurious alpha channel is stripped - the code
|
||||
* has just reduced background composition and gamma correction
|
||||
* to a simple alpha channel strip.
|
||||
*/
|
||||
png_ptr->transformations &= ~PNG_BACKGROUND;
|
||||
png_ptr->transformations &= ~PNG_GAMMA;
|
||||
png_ptr->transformations |= PNG_STRIP_ALPHA;
|
||||
}
|
||||
/* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
|
||||
else
|
||||
@@ -995,6 +1036,9 @@ png_init_read_transformations(png_structp png_ptr)
|
||||
palette[i].green = png_ptr->gamma_table[palette[i].green];
|
||||
palette[i].blue = png_ptr->gamma_table[palette[i].blue];
|
||||
}
|
||||
|
||||
/* Done the gamma correction. */
|
||||
png_ptr->transformations &= ~PNG_GAMMA;
|
||||
}
|
||||
}
|
||||
#if defined(PNG_READ_BACKGROUND_SUPPORTED)
|
||||
@@ -1032,6 +1076,10 @@ png_init_read_transformations(png_structp png_ptr)
|
||||
png_ptr->trans[i], back.blue);
|
||||
}
|
||||
}
|
||||
|
||||
/* Handled alpha, still need to strip the channel. */
|
||||
png_ptr->transformations &= ~PNG_BACKGROUND;
|
||||
png_ptr->transformations |= PNG_STRIP_ALPHA;
|
||||
}
|
||||
#endif /* PNG_READ_BACKGROUND_SUPPORTED */
|
||||
|
||||
@@ -1080,7 +1128,8 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
|
||||
{
|
||||
if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
|
||||
{
|
||||
if (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND_tRNS))
|
||||
if (png_ptr->num_trans &&
|
||||
(png_ptr->transformations & PNG_EXPAND_tRNS))
|
||||
info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA;
|
||||
else
|
||||
info_ptr->color_type = PNG_COLOR_TYPE_RGB;
|
||||
@@ -1093,8 +1142,10 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
|
||||
{
|
||||
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;
|
||||
@@ -1216,19 +1267,29 @@ void /* PRIVATE */
|
||||
png_do_read_transformations(png_structp png_ptr)
|
||||
{
|
||||
png_debug(1, "in png_do_read_transformations\n");
|
||||
#if !defined(PNG_USELESS_TESTS_SUPPORTED)
|
||||
if (png_ptr->row_buf == NULL)
|
||||
{
|
||||
#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
|
||||
char msg[50];
|
||||
|
||||
sprintf(msg, "NULL row buffer for row %ld, pass %d", png_ptr->row_number,
|
||||
png_snprintf2(msg, 50,
|
||||
"NULL row buffer for row %ld, pass %d", png_ptr->row_number,
|
||||
png_ptr->pass);
|
||||
png_error(png_ptr, msg);
|
||||
#else
|
||||
png_error(png_ptr, "NULL row buffer");
|
||||
#endif
|
||||
}
|
||||
#ifdef PNG_WARN_UNINITIALIZED_ROW
|
||||
if (!(png_ptr->flags & PNG_FLAG_ROW_INIT))
|
||||
/* Application has failed to call either png_read_start_image()
|
||||
* or png_read_update_info() after setting transforms that expand
|
||||
* pixels. This check added to libpng-1.2.19 */
|
||||
#if (PNG_WARN_UNINITIALIZED_ROW==1)
|
||||
png_error(png_ptr, "Uninitialized row");
|
||||
#else
|
||||
png_warning(png_ptr, "Uninitialized row");
|
||||
#endif
|
||||
#endif
|
||||
|
||||
#if defined(PNG_READ_EXPAND_SUPPORTED)
|
||||
@@ -1241,7 +1302,8 @@ png_do_read_transformations(png_structp png_ptr)
|
||||
}
|
||||
else
|
||||
{
|
||||
if (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND_tRNS))
|
||||
if (png_ptr->num_trans &&
|
||||
(png_ptr->transformations & PNG_EXPAND_tRNS))
|
||||
png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1,
|
||||
&(png_ptr->trans_values));
|
||||
else
|
||||
@@ -1265,9 +1327,11 @@ png_do_read_transformations(png_structp png_ptr)
|
||||
if(rgb_error)
|
||||
{
|
||||
png_ptr->rgb_to_gray_status=1;
|
||||
if(png_ptr->transformations == PNG_RGB_TO_GRAY_WARN)
|
||||
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_ERR)
|
||||
if((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
|
||||
PNG_RGB_TO_GRAY_ERR)
|
||||
png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel");
|
||||
}
|
||||
}
|
||||
@@ -3671,7 +3735,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
|
||||
{
|
||||
case 1:
|
||||
{
|
||||
gray = (png_uint_16)(gray*0xff);
|
||||
gray = (png_uint_16)((gray&0x01)*0xff);
|
||||
sp = row + (png_size_t)((row_width - 1) >> 3);
|
||||
dp = row + (png_size_t)row_width - 1;
|
||||
shift = 7 - (int)((row_width + 7) & 0x07);
|
||||
@@ -3695,7 +3759,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
|
||||
}
|
||||
case 2:
|
||||
{
|
||||
gray = (png_uint_16)(gray*0x55);
|
||||
gray = (png_uint_16)((gray&0x03)*0x55);
|
||||
sp = row + (png_size_t)((row_width - 1) >> 2);
|
||||
dp = row + (png_size_t)row_width - 1;
|
||||
shift = (int)((3 - ((row_width + 3) & 0x03)) << 1);
|
||||
@@ -3718,7 +3782,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
|
||||
}
|
||||
case 4:
|
||||
{
|
||||
gray = (png_uint_16)(gray*0x11);
|
||||
gray = (png_uint_16)((gray&0x0f)*0x11);
|
||||
sp = row + (png_size_t)((row_width - 1) >> 1);
|
||||
dp = row + (png_size_t)row_width - 1;
|
||||
shift = (int)((1 - ((row_width + 1) & 0x01)) << 2);
|
||||
@@ -3748,6 +3812,7 @@ png_do_expand(png_row_infop row_info, png_bytep row,
|
||||
{
|
||||
if (row_info->bit_depth == 8)
|
||||
{
|
||||
gray = gray & 0xff;
|
||||
sp = row + (png_size_t)row_width - 1;
|
||||
dp = row + (png_size_t)(row_width << 1) - 1;
|
||||
for (i = 0; i < row_width; i++)
|
||||
@@ -3761,12 +3826,13 @@ png_do_expand(png_row_infop row_info, png_bytep row,
|
||||
}
|
||||
else if (row_info->bit_depth == 16)
|
||||
{
|
||||
png_byte gray_high = (gray >> 8) & 0xff;
|
||||
png_byte gray_low = gray & 0xff;
|
||||
sp = row + row_info->rowbytes - 1;
|
||||
dp = row + (row_info->rowbytes << 1) - 1;
|
||||
for (i = 0; i < row_width; i++)
|
||||
{
|
||||
if (((png_uint_16)*(sp) |
|
||||
((png_uint_16)*(sp - 1) << 8)) == gray)
|
||||
if (*(sp-1) == gray_high && *(sp) == gray_low)
|
||||
{
|
||||
*dp-- = 0;
|
||||
*dp-- = 0;
|
||||
@@ -3791,13 +3857,14 @@ png_do_expand(png_row_infop row_info, png_bytep row,
|
||||
{
|
||||
if (row_info->bit_depth == 8)
|
||||
{
|
||||
png_byte red = trans_value->red & 0xff;
|
||||
png_byte green = trans_value->green & 0xff;
|
||||
png_byte blue = trans_value->blue & 0xff;
|
||||
sp = row + (png_size_t)row_info->rowbytes - 1;
|
||||
dp = row + (png_size_t)(row_width << 2) - 1;
|
||||
for (i = 0; i < row_width; i++)
|
||||
{
|
||||
if (*(sp - 2) == trans_value->red &&
|
||||
*(sp - 1) == trans_value->green &&
|
||||
*(sp - 0) == trans_value->blue)
|
||||
if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue)
|
||||
*dp-- = 0;
|
||||
else
|
||||
*dp-- = 0xff;
|
||||
@@ -3808,16 +3875,22 @@ png_do_expand(png_row_infop row_info, png_bytep row,
|
||||
}
|
||||
else if (row_info->bit_depth == 16)
|
||||
{
|
||||
png_byte red_high = (trans_value->red >> 8) & 0xff;
|
||||
png_byte green_high = (trans_value->green >> 8) & 0xff;
|
||||
png_byte blue_high = (trans_value->blue >> 8) & 0xff;
|
||||
png_byte red_low = trans_value->red & 0xff;
|
||||
png_byte green_low = trans_value->green & 0xff;
|
||||
png_byte blue_low = trans_value->blue & 0xff;
|
||||
sp = row + row_info->rowbytes - 1;
|
||||
dp = row + (png_size_t)(row_width << 3) - 1;
|
||||
for (i = 0; i < row_width; i++)
|
||||
{
|
||||
if ((((png_uint_16)*(sp - 4) |
|
||||
((png_uint_16)*(sp - 5) << 8)) == trans_value->red) &&
|
||||
(((png_uint_16)*(sp - 2) |
|
||||
((png_uint_16)*(sp - 3) << 8)) == trans_value->green) &&
|
||||
(((png_uint_16)*(sp - 0) |
|
||||
((png_uint_16)*(sp - 1) << 8)) == trans_value->blue))
|
||||
if (*(sp - 5) == red_high &&
|
||||
*(sp - 4) == red_low &&
|
||||
*(sp - 3) == green_high &&
|
||||
*(sp - 2) == green_low &&
|
||||
*(sp - 1) == blue_high &&
|
||||
*(sp ) == blue_low)
|
||||
{
|
||||
*dp-- = 0;
|
||||
*dp-- = 0;
|
||||
@@ -3937,8 +4010,8 @@ png_do_dither(png_row_infop row_info, png_bytep row,
|
||||
|
||||
#ifdef PNG_FLOATING_POINT_SUPPORTED
|
||||
#if defined(PNG_READ_GAMMA_SUPPORTED)
|
||||
static int png_gamma_shift[] =
|
||||
{0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0};
|
||||
static PNG_CONST int png_gamma_shift[] =
|
||||
{0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00};
|
||||
|
||||
/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit
|
||||
* tables, we don't make a full table if we are reducing to 8-bit in
|
||||
|
||||
Reference in New Issue
Block a user