ref: a6820e140bc4b306fb7852ae4994bf6d38f2a906
dir: /jbig2_image_png.c/
/*
jbig2dec
Copyright (c) 2002 artofcode LLC.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
$Id: jbig2_image_png.c,v 1.3 2002/07/03 00:30:20 giles Exp $
*/
#include <stdio.h>
#include <stdlib.h>
#include <png.h>
#include "jbig2.h"
#include "jbig2_priv.h"
#include "jbig2_image.h"
/* take an image structure and write it out in png format */
int jbig2_image_write_png_file(Jbig2Image *image, char *filename)
{
FILE *out;
int error;
if ((out = fopen(filename, "wb")) == NULL) {
fprintf(stderr, "unable to open '%s' for writing\n", filename);
return 1;
}
error = jbig2_image_write_png(image, out);
fclose(out);
return (error);
}
/* write out an image struct in png format to an open file pointer */
int jbig2_image_write_png(Jbig2Image *image, FILE *out)
{
int i;
png_structp png;
png_infop info;
png_bytep rowpointer;
png = png_create_write_struct(PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL);
if (png == NULL) {
fprintf(stderr, "unable to create png structure\n");
return 2;
}
info = png_create_info_struct(png);
if (info == NULL) {
fprintf(stderr, "unable to create png info structure\n");
png_destroy_write_struct(&png, (png_infopp)NULL);
return 3;
}
/* set/check error handling */
if (setjmp(png_jmpbuf(png))) {
/* we've returned here after an internal error */
fprintf(stderr, "internal error in libpng saving file\n");
png_destroy_write_struct(&png, &info);
return 4;
}
png_init_io(png, out);
/* now we fill out the info structure with our format data */
png_set_IHDR(png, info, image->width, image->height,
1, PNG_COLOR_TYPE_GRAY, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
png_write_info(png, info);
/* png natively treates 0 as black. This will convert for us */
png_set_invert_mono(png);
/* write out each row in turn */
rowpointer = (png_bytep)image->data;
for(i = 0; i < image->height; i++) {
png_write_row(png, rowpointer);
rowpointer += image->stride;
}
/* finish and clean up */
png_write_end(png, info);
png_destroy_write_struct(&png, &info);
return 0;
}