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Imported from pngcrush-1.3.6.tar

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This commit is contained in:
Glenn Randers-Pehrson
2000-03-12 07:31:31 -06:00
parent 601daa7a76
commit 66e6b07dfd
23 changed files with 218 additions and 176 deletions
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69
pngrtran.c
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@@ -1,7 +1,7 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* libpng 1.0.5s - February 18, 2000
* libpng 1.0.5v - March 11, 2000
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
* Copyright (c) 1996, 1997 Andreas Dilger
@@ -582,14 +582,25 @@ png_set_gray_to_rgb(png_structp png_ptr)
}
#endif
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) && \
defined(PNG_FLOATING_POINT_SUPPORTED)
#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED)
#if defined(PNG_FLOATING_POINT_SUPPORTED)
/* Convert a RGB image to a grayscale of the same width. This allows us,
* for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image.
*/
void
png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
double green)
double green)
{
int red_fixed = (int)((float)red*100000.0 + 0.5);
int green_fixed = (int)((float)green*100000.0 + 0.5);
png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed);
}
#endif
void
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");
switch(error_action)
@@ -610,22 +621,26 @@ png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red,
}
#endif
{
png_byte red_byte = (png_byte)((float)red*255.0 + 0.5);
png_byte green_byte = (png_byte)((float)green*255.0 + 0.5);
if(red < 0.0 || green < 0.0)
png_uint_16 red_int, green_int;
if(red > 0 && green > 0)
{
red_byte = 54;
green_byte = 183;
red_int = 6968; /* .212671 * 32768 + .5 */
green_int = 23434; /* .715160 * 32768 + .5 */
}
else if(red_byte + green_byte > 255)
else if(red + green < 100000L)
{
red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L);
green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L);
}
else
{
png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients");
red_byte = 54;
green_byte = 183;
red_int = 6968;
green_int = 23434;
}
png_ptr->rgb_to_gray_red_coeff = red_byte;
png_ptr->rgb_to_gray_green_coeff = green_byte;
png_ptr->rgb_to_gray_blue_coeff = (png_byte)(255-red_byte-green_byte);
png_ptr->rgb_to_gray_red_coeff = red_int;
png_ptr->rgb_to_gray_green_coeff = green_int;
png_ptr->rgb_to_gray_blue_coeff = (png_uint_16)(32768-red_int-green_int);
}
}
#endif
@@ -2021,11 +2036,11 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row)
*
* We approximate this with
*
* Y = 0.211 * R + 0.715 * G + 0.074 * B
* Y = 0.21268 * R + 0.7151 * G + 0.07217 * B
*
* which can be expressed with integers as
*
* Y = (54 * R + 183 * G + 19 * B)/256
* Y = (6969 * R + 23434 * G + 2365 * B)/32768
*
* The calculation is to be done in a linear colorspace.
*
@@ -2047,9 +2062,9 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
#endif
(row_info->color_type & PNG_COLOR_MASK_COLOR))
{
png_byte rc = png_ptr->rgb_to_gray_red_coeff;
png_byte gc = png_ptr->rgb_to_gray_green_coeff;
png_byte bc = png_ptr->rgb_to_gray_blue_coeff;
png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff;
png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff;
png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff;
if (row_info->color_type == PNG_COLOR_TYPE_RGB)
{
@@ -2070,7 +2085,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
{
rgb_error |= 1;
*(dp++) = png_ptr->gamma_from_1[
(rc*red+gc*green+bc*blue)>>8];
(rc*red+gc*green+bc*blue)>>15];
}
else
*(dp++) = *(sp-1);
@@ -2089,7 +2104,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
if(red != green || red != blue)
{
rgb_error |= 1;
*(dp++) = (png_byte)((rc*red+gc*green+bc*blue)>>8);
*(dp++) = (png_byte)((rc*red+gc*green+bc*blue)>>15);
}
else
*(dp++) = *(sp-1);
@@ -2124,7 +2139,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
png_ptr->gamma_shift][blue>>8];
png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1
+ bc*blue_1)>>8);
+ bc*blue_1)>>15);
w = png_ptr->gamma_16_from_1[(gray16&0xff) >>
png_ptr->gamma_shift][gray16 >> 8];
rgb_error |= 1;
@@ -2149,7 +2164,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
if(red != green || red != blue)
rgb_error |= 1;
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>8);
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
*(dp++) = (png_byte)((gray16>>8) & 0xff);
*(dp++) = (png_byte)(gray16 & 0xff);
}
@@ -2173,7 +2188,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
if(red != green || red != blue)
rgb_error |= 1;
*(dp++) = png_ptr->gamma_from_1
[(rc*red + gc*green + bc*blue)>>8];
[(rc*red + gc*green + bc*blue)>>15];
*(dp++) = *(sp++); /* alpha */
}
}
@@ -2221,7 +2236,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >>
png_ptr->gamma_shift][blue>>8];
png_uint_16 gray16 = (png_uint_16)((rc * red_1
+ gc * green_1 + bc * blue_1)>>8);
+ 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;
@@ -2246,7 +2261,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2;
if(red != green || red != blue)
rgb_error |= 1;
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>8);
gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15);
*(dp++) = (png_byte)((gray16>>8) & 0xff);
*(dp++) = (png_byte)(gray16 & 0xff);
*(dp++) = *(sp++); /* alpha */