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Diffstat (limited to 'contrib/pngminus/png2pnm.c')
| -rw-r--r-- | contrib/pngminus/png2pnm.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/contrib/pngminus/png2pnm.c b/contrib/pngminus/png2pnm.c new file mode 100644 index 0000000..010870a --- /dev/null +++ b/contrib/pngminus/png2pnm.c @@ -0,0 +1,430 @@ +/* + * 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_check_sig (buf, 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 */ + |