libpng安装与配置(Win7+VS2010)

/*
* Copyright 2002-2010 Guillaume Cottenceau.
*
* This software may be freely redistributed under the terms
* of the X11 license.
*
*/#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>#define PNG_DEBUG 3
#include <png.h>void abort_(const char * s, ...)
{
va_list args;
va_start(args, s);
vfprintf(stderr, s, args);
fprintf(stderr, "\n");
va_end(args);
abort();
}int x, y;int width, height;
png_byte color_type;
png_byte bit_depth;png_structp png_ptr;
png_infop info_ptr;
int number_of_passes;
png_bytep * row_pointers;void read_png_file(char* file_name)
{
char header[]; // 8 is the maximum size that can be checked /* open file and test for it being a png */
FILE *fp = fopen(file_name, "rb");
if (!fp)
abort_("[read_png_file] File %s could not be opened for reading", file_name);
fread(header, , , fp);
if (png_sig_cmp(header, , ))
abort_("[read_png_file] File %s is not recognized as a PNG file", file_name); /* initialize stuff */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr)
abort_("[read_png_file] png_create_read_struct failed"); info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
abort_("[read_png_file] png_create_info_struct failed"); if (setjmp(png_jmpbuf(png_ptr)))
abort_("[read_png_file] Error during init_io"); png_init_io(png_ptr, fp);
png_set_sig_bytes(png_ptr, ); png_read_info(png_ptr, info_ptr); width = png_get_image_width(png_ptr, info_ptr);
height = png_get_image_height(png_ptr, info_ptr);
color_type = png_get_color_type(png_ptr, info_ptr);
bit_depth = png_get_bit_depth(png_ptr, info_ptr); number_of_passes = png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr); /* read file */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[read_png_file] Error during read_image"); row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
for (y=; y<height; y++)
row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr)); png_read_image(png_ptr, row_pointers); fclose(fp);
}void write_png_file(char* file_name)
{
/* create file */
FILE *fp = fopen(file_name, "wb");
if (!fp)
abort_("[write_png_file] File %s could not be opened for writing", file_name); /* initialize stuff */
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if (!png_ptr)
abort_("[write_png_file] png_create_write_struct failed"); info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
abort_("[write_png_file] png_create_info_struct failed"); if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during init_io"); png_init_io(png_ptr, fp); /* write header */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during writing header"); png_set_IHDR(png_ptr, info_ptr, width, height,
bit_depth, color_type, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); png_write_info(png_ptr, info_ptr); /* write bytes */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during writing bytes"); png_write_image(png_ptr, row_pointers); /* end write */
if (setjmp(png_jmpbuf(png_ptr)))
abort_("[write_png_file] Error during end of write"); png_write_end(png_ptr, NULL); /* cleanup heap allocation */
for (y=; y<height; y++)
free(row_pointers[y]);
free(row_pointers); fclose(fp);
}void process_file(void)
{
if (png_get_color_type(png_ptr, info_ptr) == PNG_COLOR_TYPE_RGB)
abort_("[process_file] input file is PNG_COLOR_TYPE_RGB but must be PNG_COLOR_TYPE_RGBA "
"(lacks the alpha channel)"); if (png_get_color_type(png_ptr, info_ptr) != PNG_COLOR_TYPE_RGBA)
abort_("[process_file] color_type of input file must be PNG_COLOR_TYPE_RGBA (%d) (is %d)",
PNG_COLOR_TYPE_RGBA, png_get_color_type(png_ptr, info_ptr)); for (y=; y<height; y++) {
png_byte* row = row_pointers[y];
for (x=; x<width; x++) {
png_byte* ptr = &(row[x*]);
printf("Pixel at position [ %d - %d ] has RGBA values: %d - %d - %d - %d\n",
x, y, ptr[], ptr[], ptr[], ptr[]); /* set red value to 0 and green value to the blue one */
ptr[] = ;
ptr[] = ptr[];
}
}
}int main(int argc, char **argv)
{
if (argc != )
abort_("Usage: program_name <file_in> <file_out>"); read_png_file(argv[]);
process_file();
write_png_file(argv[]); return ;
}