ref: 865f3114b422acadb98f51f9ffdaf92bfe8e680d
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 1.9 2002/08/07 12:50:33 giles Exp $ */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "os_types.h" #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 */ static void jbig2_png_write_data(png_structp png_ptr, png_bytep data, png_size_t length) { png_size_t check; check = fwrite(data, 1, length, (png_FILE_p)png_ptr->io_ptr); if (check != length) { png_error(png_ptr, "Write Error"); } } static void jbig2_png_flush(png_structp png_ptr) { png_FILE_p io_ptr; io_ptr = (png_FILE_p)CVT_PTR((png_ptr->io_ptr)); if (io_ptr != NULL) fflush(io_ptr); } 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() doesn't work linking dynamically to libpng on win32 one has to either link statically or use callbacks because of runtime variations */ /* png_init_io(png, out); */ png_set_write_fn(png, (png_voidp)out, jbig2_png_write_data, jbig2_png_flush); /* 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; }