/* pngrtran.c - transforms the data in a row for PNG readers
*
* Last changed in libpng 1.2.27 [April 29, 2008]
* For conditions of distribution and use, see copyright notice in png.h
* Copyright (c) 1998-2008 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.)
*
* 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
#include "png.h"
#if defined(PNG_READ_SUPPORTED)
/* 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\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 */
break;
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 */
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 */
png_warning(png_ptr, "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;
}
switch (ancil_action)
{
case PNG_CRC_NO_CHANGE: /* leave setting as is */
break;
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 */
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 */
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_DEFAULT:
default:
png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK;
break;
}
}
#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \
defined(PNG_FLOATING_POINT_SUPPORTED)
/* 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\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");
return;
}
png_ptr->transformations |= PNG_BACKGROUND;
png_memcpy(&(png_ptr->background), background_color,
png_sizeof(png_color_16));
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);
}
#endif
#if defined(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\n");
if(png_ptr == NULL) return;
png_ptr->transformations |= PNG_16_TO_8;
}
#endif
#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED)
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
#if defined(PNG_READ_DITHER_SUPPORTED)
/* Dither 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
* simply are reducing the number of colors in a paletted image.
*/
typedef struct png_dsort_struct
{
struct png_dsort_struct FAR * next;
png_byte left;
png_byte right;
} png_dsort;
typedef png_dsort FAR * png_dsortp;
typedef png_dsort FAR * FAR * png_dsortpp;
void PNGAPI
png_set_dither(png_structp png_ptr, png_colorp palette,
int num_palette, int maximum_colors, png_uint_16p histogram,
int full_dither)
{
png_debug(1, "in png_set_dither\n");
if(png_ptr == NULL) return;
png_ptr->transformations |= PNG_DITHER;
if (!full_dither)
{
int i;
png_ptr->dither_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;
}
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. */
int i;
/* initialize an array to sort colors */
png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr,
(png_uint_32)(num_palette * png_sizeof (png_byte)));
/* initialize the dither_sort array */
for (i = 0; i < num_palette; 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
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 j;
done = 1;
for (j = 0; j < i; j++)
{
if (histogram[png_ptr->dither_sort[j]]
< histogram[png_ptr->dither_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;
done = 0;
}
}
if (done)
break;
}
/* swap the palette around, and set up a table, if necessary */
if (full_dither)
{
int j = num_palette;
/* 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)
{
do
j--;
while ((int)png_ptr->dither_sort[j] >= maximum_colors);
palette[i] = palette[j];
}
}
}
else
{
int j = num_palette;
/* 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] >= maxi
没有合适的资源?快使用搜索试试~ 我知道了~
资源推荐
资源详情
资源评论
收起资源包目录
android-opencv (2735个子文件)
all-wcprops 31KB
all-wcprops 12KB
all-wcprops 7KB
all-wcprops 7KB
all-wcprops 6KB
all-wcprops 6KB
all-wcprops 6KB
all-wcprops 6KB
all-wcprops 4KB
all-wcprops 3KB
all-wcprops 3KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 2KB
all-wcprops 1KB
all-wcprops 1KB
all-wcprops 1KB
all-wcprops 1KB
all-wcprops 1KB
all-wcprops 957B
all-wcprops 952B
all-wcprops 938B
all-wcprops 824B
all-wcprops 775B
all-wcprops 770B
all-wcprops 758B
all-wcprops 740B
all-wcprops 720B
all-wcprops 687B
all-wcprops 666B
all-wcprops 635B
all-wcprops 580B
all-wcprops 571B
all-wcprops 514B
all-wcprops 414B
all-wcprops 388B
all-wcprops 387B
all-wcprops 375B
all-wcprops 373B
all-wcprops 367B
all-wcprops 339B
all-wcprops 322B
all-wcprops 313B
all-wcprops 311B
all-wcprops 311B
all-wcprops 311B
all-wcprops 307B
all-wcprops 306B
all-wcprops 304B
all-wcprops 302B
all-wcprops 301B
all-wcprops 292B
all-wcprops 285B
all-wcprops 285B
all-wcprops 264B
all-wcprops 260B
all-wcprops 254B
all-wcprops 252B
all-wcprops 244B
all-wcprops 244B
all-wcprops 242B
all-wcprops 240B
all-wcprops 232B
all-wcprops 230B
all-wcprops 230B
all-wcprops 230B
all-wcprops 222B
all-wcprops 214B
all-wcprops 214B
all-wcprops 214B
all-wcprops 212B
all-wcprops 212B
all-wcprops 208B
all-wcprops 206B
all-wcprops 200B
all-wcprops 186B
all-wcprops 115B
all-wcprops 106B
all-wcprops 103B
all-wcprops 103B
all-wcprops 103B
all-wcprops 101B
all-wcprops 101B
all-wcprops 101B
all-wcprops 101B
all-wcprops 100B
all-wcprops 100B
all-wcprops 99B
all-wcprops 99B
all-wcprops 98B
all-wcprops 98B
all-wcprops 97B
all-wcprops 97B
共 2735 条
- 1
- 2
- 3
- 4
- 5
- 6
- 28
zsoftdevelop
- 粉丝: 12
- 资源: 11
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
最新资源
资源上传下载、课程学习等过程中有任何疑问或建议,欢迎提出宝贵意见哦~我们会及时处理!
点击此处反馈
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功
- 1
- 2
前往页