| /* |
| * png2pnm.c --- conversion from PNG-file to PGM/PPM-file |
| * copyright (C) 1999 by Willem van Schaik <willem@schaik.com> |
| * |
| * version 1.0 - 1999.10.15 - First version. |
| * |
| * Permission to use, copy, modify, and distribute this software and |
| * its documentation for any purpose and without fee is hereby granted, |
| * provided that the above copyright notice appear in all copies and |
| * that both that copyright notice and this permission notice appear in |
| * supporting documentation. This software is provided "as is" without |
| * express or implied warranty. |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #ifdef __TURBOC__ |
| #include <mem.h> |
| #include <fcntl.h> |
| #endif |
| |
| #ifndef BOOL |
| #define BOOL unsigned char |
| #endif |
| #ifndef TRUE |
| #define TRUE (BOOL) 1 |
| #endif |
| #ifndef FALSE |
| #define FALSE (BOOL) 0 |
| #endif |
| |
| #ifdef __TURBOC__ |
| #define STDIN 0 |
| #define STDOUT 1 |
| #define STDERR 2 |
| #endif |
| |
| /* to make png2pnm verbose so we can find problems (needs to be before png.h) */ |
| #ifndef PNG_DEBUG |
| #define PNG_DEBUG 0 |
| #endif |
| |
| #include "png.h" |
| |
| /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */ |
| #ifndef png_jmpbuf |
| # define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf) |
| #endif |
| |
| /* function prototypes */ |
| |
| int main (int argc, char *argv[]); |
| void usage (); |
| BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha); |
| |
| /* |
| * main |
| */ |
| |
| int main(int argc, char *argv[]) |
| { |
| FILE *fp_rd = stdin; |
| FILE *fp_wr = stdout; |
| FILE *fp_al = NULL; |
| BOOL raw = TRUE; |
| BOOL alpha = FALSE; |
| int argi; |
| |
| for (argi = 1; argi < argc; argi++) |
| { |
| if (argv[argi][0] == '-') |
| { |
| switch (argv[argi][1]) |
| { |
| case 'n': |
| raw = FALSE; |
| break; |
| case 'r': |
| raw = TRUE; |
| break; |
| case 'a': |
| alpha = TRUE; |
| argi++; |
| if ((fp_al = fopen (argv[argi], "wb")) == NULL) |
| { |
| fprintf (stderr, "PNM2PNG\n"); |
| fprintf (stderr, "Error: can not create alpha-channel file %s\n", argv[argi]); |
| exit (1); |
| } |
| break; |
| case 'h': |
| case '?': |
| usage(); |
| exit(0); |
| break; |
| default: |
| fprintf (stderr, "PNG2PNM\n"); |
| fprintf (stderr, "Error: unknown option %s\n", argv[argi]); |
| usage(); |
| exit(1); |
| break; |
| } /* end switch */ |
| } |
| else if (fp_rd == stdin) |
| { |
| if ((fp_rd = fopen (argv[argi], "rb")) == NULL) |
| { |
| fprintf (stderr, "PNG2PNM\n"); |
| fprintf (stderr, "Error: file %s does not exist\n", argv[argi]); |
| exit (1); |
| } |
| } |
| else if (fp_wr == stdout) |
| { |
| if ((fp_wr = fopen (argv[argi], "wb")) == NULL) |
| { |
| fprintf (stderr, "PNG2PNM\n"); |
| fprintf (stderr, "Error: can not create file %s\n", argv[argi]); |
| exit (1); |
| } |
| } |
| else |
| { |
| fprintf (stderr, "PNG2PNM\n"); |
| fprintf (stderr, "Error: too many parameters\n"); |
| usage(); |
| exit(1); |
| } |
| } /* end for */ |
| |
| #ifdef __TURBOC__ |
| /* set stdin/stdout if required to binary */ |
| if (fp_rd == stdin) |
| { |
| setmode (STDIN, O_BINARY); |
| } |
| if ((raw) && (fp_wr == stdout)) |
| { |
| setmode (STDOUT, O_BINARY); |
| } |
| #endif |
| |
| /* call the conversion program itself */ |
| if (png2pnm (fp_rd, fp_wr, fp_al, raw, alpha) == FALSE) |
| { |
| fprintf (stderr, "PNG2PNM\n"); |
| fprintf (stderr, "Error: unsuccessful convertion of PNG-image\n"); |
| exit(1); |
| } |
| |
| /* close input file */ |
| fclose (fp_rd); |
| /* close output file */ |
| fclose (fp_wr); |
| /* close alpha file */ |
| if (alpha) |
| fclose (fp_al); |
| |
| return 0; |
| } |
| |
| /* |
| * usage |
| */ |
| |
| void usage() |
| { |
| fprintf (stderr, "PNG2PNM\n"); |
| fprintf (stderr, " by Willem van Schaik, 1999\n"); |
| #ifdef __TURBOC__ |
| fprintf (stderr, " for Turbo-C and Borland-C compilers\n"); |
| #else |
| fprintf (stderr, " for Linux (and Unix) compilers\n"); |
| #endif |
| fprintf (stderr, "Usage: png2pnm [options] <file>.png [<file>.pnm]\n"); |
| fprintf (stderr, " or: ... | png2pnm [options]\n"); |
| fprintf (stderr, "Options:\n"); |
| fprintf (stderr, " -r[aw] write pnm-file in binary format (P4/P5/P6) (default)\n"); |
| fprintf (stderr, " -n[oraw] write pnm-file in ascii format (P1/P2/P3)\n"); |
| fprintf (stderr, " -a[lpha] <file>.pgm write PNG alpha channel as pgm-file\n"); |
| fprintf (stderr, " -h | -? print this help-information\n"); |
| } |
| |
| /* |
| * png2pnm |
| */ |
| |
| BOOL png2pnm (FILE *png_file, FILE *pnm_file, FILE *alpha_file, BOOL raw, BOOL alpha) |
| { |
| png_struct *png_ptr = NULL; |
| png_info *info_ptr = NULL; |
| png_byte buf[8]; |
| png_byte *png_pixels = NULL; |
| png_byte **row_pointers = NULL; |
| png_byte *pix_ptr = NULL; |
| png_uint_32 row_bytes; |
| |
| png_uint_32 width; |
| png_uint_32 height; |
| int bit_depth; |
| int channels; |
| int color_type; |
| int alpha_present; |
| int row, col; |
| int ret; |
| int i; |
| long dep_16; |
| |
| /* read and check signature in PNG file */ |
| ret = fread (buf, 1, 8, png_file); |
| if (ret != 8) |
| return FALSE; |
| |
| ret = png_sig_cmp (buf, 0, 8); |
| if (ret) |
| return FALSE; |
| |
| /* create png and info structures */ |
| |
| png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, |
| NULL, NULL, NULL); |
| if (!png_ptr) |
| return FALSE; /* out of memory */ |
| |
| info_ptr = png_create_info_struct (png_ptr); |
| if (!info_ptr) |
| { |
| png_destroy_read_struct (&png_ptr, NULL, NULL); |
| return FALSE; /* out of memory */ |
| } |
| |
| if (setjmp (png_jmpbuf(png_ptr))) |
| { |
| png_destroy_read_struct (&png_ptr, &info_ptr, NULL); |
| return FALSE; |
| } |
| |
| /* set up the input control for C streams */ |
| png_init_io (png_ptr, png_file); |
| png_set_sig_bytes (png_ptr, 8); /* we already read the 8 signature bytes */ |
| |
| /* read the file information */ |
| png_read_info (png_ptr, info_ptr); |
| |
| /* get size and bit-depth of the PNG-image */ |
| png_get_IHDR (png_ptr, info_ptr, |
| &width, &height, &bit_depth, &color_type, |
| NULL, NULL, NULL); |
| |
| /* set-up the transformations */ |
| |
| /* transform paletted images into full-color rgb */ |
| if (color_type == PNG_COLOR_TYPE_PALETTE) |
| png_set_expand (png_ptr); |
| /* expand images to bit-depth 8 (only applicable for grayscale images) */ |
| if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) |
| png_set_expand (png_ptr); |
| /* transform transparency maps into full alpha-channel */ |
| if (png_get_valid (png_ptr, info_ptr, PNG_INFO_tRNS)) |
| png_set_expand (png_ptr); |
| |
| #ifdef NJET |
| /* downgrade 16-bit images to 8 bit */ |
| if (bit_depth == 16) |
| png_set_strip_16 (png_ptr); |
| /* transform grayscale images into full-color */ |
| if (color_type == PNG_COLOR_TYPE_GRAY || |
| color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| png_set_gray_to_rgb (png_ptr); |
| /* only if file has a file gamma, we do a correction */ |
| if (png_get_gAMA (png_ptr, info_ptr, &file_gamma)) |
| png_set_gamma (png_ptr, (double) 2.2, file_gamma); |
| #endif |
| |
| /* all transformations have been registered; now update info_ptr data, |
| * get rowbytes and channels, and allocate image memory */ |
| |
| png_read_update_info (png_ptr, info_ptr); |
| |
| /* get the new color-type and bit-depth (after expansion/stripping) */ |
| png_get_IHDR (png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, |
| NULL, NULL, NULL); |
| |
| /* check for 16-bit files */ |
| if (bit_depth == 16) |
| { |
| raw = FALSE; |
| #ifdef __TURBOC__ |
| pnm_file->flags &= ~((unsigned) _F_BIN); |
| #endif |
| } |
| |
| /* calculate new number of channels and store alpha-presence */ |
| if (color_type == PNG_COLOR_TYPE_GRAY) |
| channels = 1; |
| else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| channels = 2; |
| else if (color_type == PNG_COLOR_TYPE_RGB) |
| channels = 3; |
| else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| channels = 4; |
| else |
| channels = 0; /* should never happen */ |
| alpha_present = (channels - 1) % 2; |
| |
| /* check if alpha is expected to be present in file */ |
| if (alpha && !alpha_present) |
| { |
| fprintf (stderr, "PNG2PNM\n"); |
| fprintf (stderr, "Error: PNG-file doesn't contain alpha channel\n"); |
| exit (1); |
| } |
| |
| /* row_bytes is the width x number of channels x (bit-depth / 8) */ |
| row_bytes = png_get_rowbytes (png_ptr, info_ptr); |
| |
| if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL) { |
| png_destroy_read_struct (&png_ptr, &info_ptr, NULL); |
| return FALSE; |
| } |
| |
| if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL) |
| { |
| png_destroy_read_struct (&png_ptr, &info_ptr, NULL); |
| free (png_pixels); |
| png_pixels = NULL; |
| return FALSE; |
| } |
| |
| /* set the individual row_pointers to point at the correct offsets */ |
| for (i = 0; i < (height); i++) |
| row_pointers[i] = png_pixels + i * row_bytes; |
| |
| /* now we can go ahead and just read the whole image */ |
| png_read_image (png_ptr, row_pointers); |
| |
| /* read rest of file, and get additional chunks in info_ptr - REQUIRED */ |
| png_read_end (png_ptr, info_ptr); |
| |
| /* clean up after the read, and free any memory allocated - REQUIRED */ |
| png_destroy_read_struct (&png_ptr, &info_ptr, (png_infopp) NULL); |
| |
| /* write header of PNM file */ |
| |
| if ((color_type == PNG_COLOR_TYPE_GRAY) || |
| (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) |
| { |
| fprintf (pnm_file, "%s\n", (raw) ? "P5" : "P2"); |
| fprintf (pnm_file, "%d %d\n", (int) width, (int) height); |
| fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L)); |
| } |
| else if ((color_type == PNG_COLOR_TYPE_RGB) || |
| (color_type == PNG_COLOR_TYPE_RGB_ALPHA)) |
| { |
| fprintf (pnm_file, "%s\n", (raw) ? "P6" : "P3"); |
| fprintf (pnm_file, "%d %d\n", (int) width, (int) height); |
| fprintf (pnm_file, "%ld\n", ((1L << (int) bit_depth) - 1L)); |
| } |
| |
| /* write header of PGM file with alpha channel */ |
| |
| if ((alpha) && |
| ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) || |
| (color_type == PNG_COLOR_TYPE_RGB_ALPHA))) |
| { |
| fprintf (alpha_file, "%s\n", (raw) ? "P5" : "P2"); |
| fprintf (alpha_file, "%d %d\n", (int) width, (int) height); |
| fprintf (alpha_file, "%ld\n", ((1L << (int) bit_depth) - 1L)); |
| } |
| |
| /* write data to PNM file */ |
| pix_ptr = png_pixels; |
| |
| for (row = 0; row < height; row++) |
| { |
| for (col = 0; col < width; col++) |
| { |
| for (i = 0; i < (channels - alpha_present); i++) |
| { |
| if (raw) |
| fputc ((int) *pix_ptr++ , pnm_file); |
| else |
| if (bit_depth == 16){ |
| dep_16 = (long) *pix_ptr++; |
| fprintf (pnm_file, "%ld ", (dep_16 << 8) + ((long) *pix_ptr++)); |
| } |
| else |
| fprintf (pnm_file, "%ld ", (long) *pix_ptr++); |
| } |
| if (alpha_present) |
| { |
| if (!alpha) |
| { |
| pix_ptr++; /* alpha */ |
| if (bit_depth == 16) |
| pix_ptr++; |
| } |
| else /* output alpha-channel as pgm file */ |
| { |
| if (raw) |
| fputc ((int) *pix_ptr++ , alpha_file); |
| else |
| if (bit_depth == 16){ |
| dep_16 = (long) *pix_ptr++; |
| fprintf (alpha_file, "%ld ", (dep_16 << 8) + (long) *pix_ptr++); |
| } |
| else |
| fprintf (alpha_file, "%ld ", (long) *pix_ptr++); |
| } |
| } /* if alpha_present */ |
| |
| if (!raw) |
| if (col % 4 == 3) |
| fprintf (pnm_file, "\n"); |
| } /* end for col */ |
| |
| if (!raw) |
| if (col % 4 != 0) |
| fprintf (pnm_file, "\n"); |
| } /* end for row */ |
| |
| if (row_pointers != (unsigned char**) NULL) |
| free (row_pointers); |
| if (png_pixels != (unsigned char*) NULL) |
| free (png_pixels); |
| |
| return TRUE; |
| |
| } /* end of source */ |
| |