mewin/libpng
1
0
Fork 0
mirror of https://git.code.sf.net/p/libpng/code.git synced 2025-07-10 18:04:09 +02:00
Code Issues Projects Releases Wiki Activity

Imported from pngcrush-1.5.9.tar

Browse Source
This commit is contained in:
Glenn Randers-Pehrson
2002-07-08 19:10:41 -05:00
parent 2eb0852fd6
commit bfee24162a
23 changed files with 1214 additions and 443 deletions
Download Patch File Download Diff File Expand all files Collapse all files

168
pngrtran.c
View File

@@ -1,9 +1,9 @@
/* pngrtran.c - transforms the data in a row for PNG readers
*
* libpng 1.2.1 - December 12, 2001
* libpng 1.2.4 - July 8, 2002
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2001 Glenn Randers-Pehrson
* Copyright (c) 1998-2002 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.)
*
@@ -167,15 +167,14 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
Perhaps not the best solution, but good enough. */
int i;
png_bytep sort;
/* initialize an array to sort colors */
sort = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_palette
* sizeof (png_byte)));
png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * sizeof (png_byte)));
/* initialize the sort array */
/* initialize the dither_sort array */
for (i = 0; i < num_palette; i++)
sort[i] = (png_byte)i;
png_ptr->dither_sort[i] = (png_byte)i;
/* Find the least used palette entries by starting a
bubble sort, and running it until we have sorted
@@ -191,13 +190,14 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
done = 1;
for (j = 0; j < i; j++)
{
if (histogram[sort[j]] < histogram[sort[j + 1]])
if (histogram[png_ptr->dither_sort[j]]
< histogram[png_ptr->dither_sort[j + 1]])
{
png_byte t;
t = sort[j];
sort[j] = sort[j + 1];
sort[j + 1] = t;
t = png_ptr->dither_sort[j];
png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1];
png_ptr->dither_sort[j + 1] = t;
done = 0;
}
}
@@ -214,11 +214,11 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
move the others */
for (i = 0; i < maximum_colors; i++)
{
if ((int)sort[i] >= maximum_colors)
if ((int)png_ptr->dither_sort[i] >= maximum_colors)
{
do
j--;
while ((int)sort[j] >= maximum_colors);
while ((int)png_ptr->dither_sort[j] >= maximum_colors);
palette[i] = palette[j];
}
}
@@ -232,13 +232,13 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
for (i = 0; i < maximum_colors; i++)
{
/* only move the colors we need to */
if ((int)sort[i] >= maximum_colors)
if ((int)png_ptr->dither_sort[i] >= maximum_colors)
{
png_color tmp_color;
do
j--;
while ((int)sort[j] >= maximum_colors);
while ((int)png_ptr->dither_sort[j] >= maximum_colors);
tmp_color = palette[j];
palette[j] = palette[i];
@@ -276,7 +276,8 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
}
}
}
png_free(png_ptr, sort);
png_free(png_ptr, png_ptr->dither_sort);
png_ptr->dither_sort=NULL;
}
else
{
@@ -291,23 +292,22 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
int i;
int max_d;
int num_new_palette;
png_dsortp t;
png_dsortpp hash;
png_bytep index_to_palette;
/* where the original index currently is in the palette */
png_bytep palette_to_index;
/* which original index points to this palette color */
t=NULL;
/* initialize palette index arrays */
index_to_palette = (png_bytep)png_malloc(png_ptr,
png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * sizeof (png_byte)));
palette_to_index = (png_bytep)png_malloc(png_ptr,
png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * sizeof (png_byte)));
/* initialize the sort array */
for (i = 0; i < num_palette; i++)
{
index_to_palette[i] = (png_byte)i;
palette_to_index[i] = (png_byte)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 *
@@ -342,18 +342,22 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
if (d <= max_d)
{
png_dsortp t;
t = (png_dsortp)png_malloc(png_ptr, (png_uint_32)(sizeof
(png_dsort)));
t = (png_dsortp)png_malloc_warn(png_ptr,
(png_uint_32)(sizeof(png_dsort)));
if (t == NULL)
break;
t->next = hash[d];
t->left = (png_byte)i;
t->right = (png_byte)j;
hash[d] = t;
}
}
if (t == NULL)
break;
}
if (t != NULL)
for (i = 0; i <= max_d; i++)
{
if (hash[i] != NULL)
@@ -362,8 +366,10 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
for (p = hash[i]; p; p = p->next)
{
if ((int)index_to_palette[p->left] < num_new_palette &&
(int)index_to_palette[p->right] < num_new_palette)
if ((int)png_ptr->index_to_palette[p->left]
< num_new_palette &&
(int)png_ptr->index_to_palette[p->right]
< num_new_palette)
{
int j, next_j;
@@ -379,7 +385,8 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
}
num_new_palette--;
palette[index_to_palette[j]] = palette[num_new_palette];
palette[png_ptr->index_to_palette[j]]
= palette[num_new_palette];
if (!full_dither)
{
int k;
@@ -387,23 +394,23 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
for (k = 0; k < num_palette; k++)
{
if (png_ptr->dither_index[k] ==
index_to_palette[j])
png_ptr->index_to_palette[j])
png_ptr->dither_index[k] =
index_to_palette[next_j];
png_ptr->index_to_palette[next_j];
if ((int)png_ptr->dither_index[k] ==
num_new_palette)
png_ptr->dither_index[k] =
index_to_palette[j];
png_ptr->index_to_palette[j];
}
}
index_to_palette[palette_to_index[num_new_palette]] =
index_to_palette[j];
palette_to_index[index_to_palette[j]] =
palette_to_index[num_new_palette];
png_ptr->index_to_palette[png_ptr->palette_to_index
[num_new_palette]] = png_ptr->index_to_palette[j];
png_ptr->palette_to_index[png_ptr->index_to_palette[j]]
= png_ptr->palette_to_index[num_new_palette];
index_to_palette[j] = (png_byte)num_new_palette;
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;
@@ -420,8 +427,6 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
png_dsortp p = hash[i];
while (p)
{
png_dsortp t;
t = p->next;
png_free(png_ptr, p);
p = t;
@@ -432,8 +437,10 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
max_d += 96;
}
png_free(png_ptr, hash);
png_free(png_ptr, palette_to_index);
png_free(png_ptr, index_to_palette);
png_free(png_ptr, png_ptr->palette_to_index);
png_free(png_ptr, png_ptr->index_to_palette);
png_ptr->palette_to_index=NULL;
png_ptr->index_to_palette=NULL;
}
num_palette = maximum_colors;
}
@@ -510,13 +517,19 @@ png_set_dither(png_structp png_ptr, png_colorp palette,
* only do transformations on images where the file_gamma and screen_gamma
* are not close reciprocals, otherwise it slows things down slightly, and
* also needlessly introduces small errors.
*
* We will turn off gamma transformation later if no semitransparent entries
* are present in the tRNS array for palette images. We can't do it here
* because we don't necessarily have the tRNS chunk yet.
*/
void PNGAPI
png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma)
{
png_debug(1, "in png_set_gamma\n");
if (fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD)
png_ptr->transformations |= PNG_GAMMA;
if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) ||
(png_ptr->color_type & PNG_COLOR_MASK_ALPHA) ||
(png_ptr->color_type == PNG_COLOR_TYPE_PALETTE))
png_ptr->transformations |= PNG_GAMMA;
png_ptr->gamma = (float)file_gamma;
png_ptr->screen_gamma = (float)scrn_gamma;
}
@@ -692,23 +705,23 @@ png_init_read_transformations(png_structp png_ptr)
{
case 1:
png_ptr->background.gray *= (png_uint_16)0xff;
png_ptr->background.red = png_ptr->background.green =
png_ptr->background.blue = png_ptr->background.gray;
png_ptr->background.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.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;
png_ptr->background.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.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;
png_ptr->background.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.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.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.gray;
break;
}
}
@@ -746,6 +759,22 @@ png_init_read_transformations(png_structp png_ptr)
png_ptr->background_1 = png_ptr->background;
#endif
#if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED)
if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0)
&& (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0)
< PNG_GAMMA_THRESHOLD))
{
int i,k;
k=0;
for (i=0; i<png_ptr->num_trans; i++)
{
if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff)
k=1; /* partial transparency is present */
}
if (k == 0)
png_ptr->transformations &= (~PNG_GAMMA);
}
if (png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY))
{
png_build_gamma_table(png_ptr);
@@ -754,6 +783,8 @@ png_init_read_transformations(png_structp png_ptr)
{
if (color_type == PNG_COLOR_TYPE_PALETTE)
{
/* could skip if no transparency and
*/
png_color back, back_1;
png_colorp palette = png_ptr->palette;
int num_palette = png_ptr->num_palette;
@@ -848,7 +879,7 @@ png_init_read_transformations(png_structp png_ptr)
}
}
}
/* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN)*/
/* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */
else
/* color_type != PNG_COLOR_TYPE_PALETTE */
{
@@ -873,9 +904,16 @@ png_init_read_transformations(png_structp png_ptr)
break;
}
if (color_type & PNG_COLOR_MASK_COLOR)
png_ptr->background_1.gray = (png_uint_16)(pow(
(double)png_ptr->background.gray / m, g) * m + .5);
png_ptr->background.gray = (png_uint_16)(pow(
(double)png_ptr->background.gray / m, gs) * m + .5);
if ((png_ptr->background.red != png_ptr->background.green) ||
(png_ptr->background.red != png_ptr->background.blue) ||
(png_ptr->background.red != png_ptr->background.gray))
{
/* RGB or RGBA */
/* RGB or RGBA with color background */
png_ptr->background_1.red = (png_uint_16)(pow(
(double)png_ptr->background.red / m, g) * m + .5);
png_ptr->background_1.green = (png_uint_16)(pow(
@@ -891,11 +929,11 @@ png_init_read_transformations(png_structp png_ptr)
}
else
{
/* GRAY or GRAY ALPHA */
png_ptr->background_1.gray = (png_uint_16)(pow(
(double)png_ptr->background.gray / m, g) * m + .5);
png_ptr->background.gray = (png_uint_16)(pow(
(double)png_ptr->background.gray / m, gs) * m + .5);
/* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */
png_ptr->background_1.red = png_ptr->background_1.green
= png_ptr->background_1.blue = png_ptr->background_1.gray;
png_ptr->background.red = png_ptr->background.green
= png_ptr->background.blue = png_ptr->background.gray;
}
}
}
@@ -2315,7 +2353,7 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row)
* paletted. Most useful for gamma correction and simplification
* of code.
*/
void /* PRIVATE */
void PNGAPI
png_build_grayscale_palette(int bit_depth, png_colorp palette)
{
int num_palette;
@@ -3150,17 +3188,17 @@ png_do_background(png_row_infop row_info, png_bytep row,
png_uint_16 v, w, x;
v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
png_composite_16(w, v, a, background->red);
png_composite_16(w, v, a, background_1->red);
x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
*dp = (png_byte)((x >> 8) & 0xff);
*(dp + 1) = (png_byte)(x & 0xff);
v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
png_composite_16(w, v, a, background->green);
png_composite_16(w, v, a, background_1->green);
x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8];
*(dp + 2) = (png_byte)((x >> 8) & 0xff);
*(dp + 3) = (png_byte)(x & 0xff);
v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
png_composite_16(w, v, a, background->blue);
png_composite_16(w, v, a, background_1->blue);
x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8];
*(dp + 4) = (png_byte)((x >> 8) & 0xff);
*(dp + 5) = (png_byte)(x & 0xff);