--- /dev/null
+/*
+ * 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 */
+
projects / synfig.git / blobdiff