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-rw-r--r--contrib/pngminus/README153
-rw-r--r--contrib/pngminus/makefile.std52
-rw-r--r--contrib/pngminus/makefile.tc338
-rw-r--r--contrib/pngminus/png2pnm.bat41
-rw-r--r--contrib/pngminus/png2pnm.c420
-rwxr-xr-xcontrib/pngminus/png2pnm.sh41
-rw-r--r--contrib/pngminus/pngminus.bat4
-rwxr-xr-xcontrib/pngminus/pngminus.sh4
-rw-r--r--contrib/pngminus/pnm2png.bat41
-rw-r--r--contrib/pngminus/pnm2png.c527
-rwxr-xr-xcontrib/pngminus/pnm2png.sh41
11 files changed, 1362 insertions, 0 deletions
diff --git a/contrib/pngminus/README b/contrib/pngminus/README
new file mode 100644
index 000000000..cfcb20c34
--- /dev/null
+++ b/contrib/pngminus/README
@@ -0,0 +1,153 @@
+PngMinus
+--------
+(copyright Willem van Schaik, 1999)
+
+
+License
+-------
+
+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.
+
+
+Some history
+------------
+Soon after the creation of PNG in 1995, the need was felt for a set of
+pnmtopng / pngtopnm utilities. Independantly Alexander Lehmann and I
+(Willem van Schaik) started such a project. Luckily we discovered this
+and merged the two together into pnmtopng.tar.gz, which is available
+from a/o ftp://swrinde.nde.swri.edu/pub/png/.
+
+These two utilities have many, many options and make use of most of the
+features of PNG, like gamma, alpha, sbit, text-chunks, etc. This makes
+the utilities quite complex and by now not anymore very maintainable.
+When we wrote these programs, libpng was still in an early stage.
+Therefore, lots of the functionality that we put in our software can now
+be done using transform-functions in libpng.
+
+Finally, to compile these programs, you need to have installed and
+compiled three libraries: libpng, zlib and netpbm. Especially the latter
+makes the whole setup a bit bulky. But that's unavoidable given the many
+features of pnmtopng.
+
+
+What now
+--------
+At this moment libpng is in a very stable state and can do much of the
+work done in pnmtopng. Also, pnmtopng needs to be upgraded to the new
+interface of libpng. Hence, it is time for a rewrite from the ground up
+of pnmtopng and pngtopnm. This will happen in the near future (stay
+tuned). The new package will get a different name to distinguish it from
+the old one: PngPlus.
+
+To experiment a bit with the new interface of libpng, I started off with
+a small prototype that contains only the basic functionality. It doesn't
+have any of the options to read or write special chunks and it will do
+no gamma correction. But this makes it also a simple program that is
+quite easy to understand and can serve well as a template for other
+software developments. (By now there are of course a couple of programs,
+like Greg Roelofs' rpng/wpng, that can be used just as good.)
+
+
+Can and can not
+---------------
+As this is the small brother of the future PngPlus, I called this fellow
+PngMinus. Because I started this development in good-old Turbo-C, I
+avoided the use the netpbm library, which requires DOS extenders. Again,
+another reason to call it PngMinus (minus netpbm :-). So, part of the
+program are some elementary routines to read / write pgm- and ppm-files.
+It does not read b&w pbm-files.
+
+The downside of this approach is that you can not use them on images
+that require blocks of memory bigger than 64k (the DOS version). For
+larger images you will get an out-of-memory error.
+
+As said before, PngMinus doesn't correct for gamma. When reading
+png-files you can do this just as well by piping the output of png2pnm
+to pnmgamma, one of the standard PbmPlus tools. This same scenario will
+most probably also be followed in the full-blown future PngPlus, with
+the addition of course of the possibility to create gamma-chunks when
+writing png-files.
+
+On the other hand it supports alpha-channels. When reading a png-image
+you can write the alpha-channel into a pgm-file. And when creating an
+RGB+A png-image, you just combine a ppm-file with a corresponding
+pgm-file containing the alpha-channel. When reading, transparency chunks
+are converted into an alpha-channel and from there on treated the same
+way.
+
+Finally you can opt for writing ascii or binary pgm- and ppm-files. When
+the bit-depth is 16, the format will always be ascii.
+
+
+Using it
+--------
+To distinguish them from pnmtopng and PngPlus, the utilities are named
+png2pnm and pnm2png (2 instead of to). The input- and output-files can
+be given as parameters or through redirection. Therefore the programs
+can be part of a pipe.
+
+To list the options type "png2pnm -h" or "pnm2png -h".
+
+
+Just like IKEA
+--------------
+You have to put it together yourself. I did test the software under
+MS-DOS with Turbo-C 3.0 and under RedHat Linux 4.2 with gcc. In both
+cases I used libpng-1.0.4 and zlib-1.1.3. Later versions should be OK,
+however some older libpng versions have a bug in pngmem.c when using
+Turbo-C 3.0 (see below).
+
+You can build it using one of the two makefiles (make -f makefile.###)
+or use the batch/script files pngminus.bat / pngminus.sh. This assumes
+that you have built the libraries in ../libpng and ../zlib. Using Linux,
+make sure that you have built libpng with makefile.std and not
+makefile.linux (also called .lnx in earlier versions of libpng). The
+latter creates a .so shared-library, while the PngMinus makefile assumes
+a normal .a static library.
+
+If you create a ../pngsuite directory and then store the basn####.png
+files from PngSuite (http://www.schaik.com/pngsuite/) in there, you can
+test in one go the proper functioning of PngMinus, see png2pnm.bat and
+pnm2png.bat (or the .sh versions).
+
+
+Warranty
+-------
+Please, remember that this was just a small experiment to learn a few
+things. It will have many unforeseen features <vbg>. Who said bugs? Use
+it when you are in need for something simple or when you want to start
+developing your own stuff.
+
+
+The Turbo bug
+-------------
+** pngmem.old
+ hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+ hptr += 16L;
+** pngmem.c
+ hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
+ hptr = hptr + 16L;
+**
+
+** pngmem.old
+ png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+ hptr += (png_uint_32)65536L;
+** pngmem.c
+ png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
+ hptr = hptr + 65536L;
+**
+
+
+The end
+-------
+Willem van Schaik
+mailto:willem@schaik.com
+http://www.schaik.com/png/
+-------
+Oct 1999
+
diff --git a/contrib/pngminus/makefile.std b/contrib/pngminus/makefile.std
new file mode 100644
index 000000000..9d2edf797
--- /dev/null
+++ b/contrib/pngminus/makefile.std
@@ -0,0 +1,52 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# Linux / Unix
+
+CC=cc -O
+LD=cc -O
+#CC=gcc -O
+#LD=gcc -O
+LB=ar
+RM=rm
+CP=cp
+
+PNGPATH = /usr/local
+PNGINC = -I$(PNGPATH)/include
+#PNGLIB = -L$(PNGPATH)/lib -lpng
+PNGLIB = $(PNGPATH)/lib/libpng.a
+
+ZPATH = /usr/local
+ZINC = -I$(ZPATH)/include
+#ZLIB = -L$(ZPATH)/lib -lz
+ZLIB = $(ZPATH)/lib/libz.a
+
+CCFLAGS=-I$(PNGINC) -I$(ZINC)
+LDFLAGS=-L$(PNGLIB) -L$(ZLIB)
+C=.c
+O=.o
+L=.a
+E=
+
+# dependencies
+
+all: png2pnm$(E) pnm2png$(E)
+
+png2pnm$(O): png2pnm$(C)
+ $(CC) -c $(CCFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+ $(LD) -o png2pnm$(E) png2pnm$(O) $(LDFLAGS) -lpng -lz -lm
+
+pnm2png$(O): pnm2png$(C)
+ $(CC) -c $(CCFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+ $(LD) -o pnm2png$(E) pnm2png$(O) $(LDFLAGS) -lpng -lz -lm
+
+clean:
+ $(RM) png2pnm$(O)
+ $(RM) pnm2png$(O)
+ $(RM) png2pnm$(E)
+ $(RM) pnm2png$(E)
+
+# End of makefile for png2pnm / pnm2png
+
diff --git a/contrib/pngminus/makefile.tc3 b/contrib/pngminus/makefile.tc3
new file mode 100644
index 000000000..404f18d5b
--- /dev/null
+++ b/contrib/pngminus/makefile.tc3
@@ -0,0 +1,38 @@
+# Makefile for PngMinus (png2pnm and pnm2png)
+# TurboC++ 3.0
+
+CC=tcc -Ic:\tc3\inc
+LD=tcc -Lc:\tc3\lib
+LB=tlib
+RM=del
+CP=copy
+MODEL=l
+CCFLAGS=-O -m$(MODEL) -I..\libpng -I..\zlib
+LDFLAGS=-m$(MODEL) -L..\libpng -L..\zlib
+C=.c
+O=.obj
+L=.lib
+E=.exe
+
+# dependencies
+
+all: png2pnm$(E) pnm2png$(E)
+
+png2pnm$(O): png2pnm$(C)
+ $(CC) -c $(CCFLAGS) png2pnm$(C)
+
+png2pnm$(E): png2pnm$(O)
+ $(LD) $(LDFLAGS) png2pnm$(O) libpng$(L) zlib$(L)
+
+pnm2png$(O): pnm2png$(C)
+ $(CC) -c $(CCFLAGS) pnm2png$(C)
+
+pnm2png$(E): pnm2png$(O)
+ $(LD) $(LDFLAGS) pnm2png$(O) libpng$(L) zlib$(L)
+
+clean:
+ $(RM) *$(O)
+ $(RM) *$(E)
+
+# End of makefile for png2pnm / pnm2png
+
diff --git a/contrib/pngminus/png2pnm.bat b/contrib/pngminus/png2pnm.bat
new file mode 100644
index 000000000..449cf3675
--- /dev/null
+++ b/contrib/pngminus/png2pnm.bat
@@ -0,0 +1,41 @@
+REM -- grayscale
+png2pnm.exe -noraw ..\pngsuite\basn0g01.png basn0g01.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g02.png basn0g02.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g04.png basn0g04.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g08.png basn0g08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn0g16.png basn0g16.pgm
+REM -- full-color
+png2pnm.exe -noraw ..\pngsuite\basn2c08.png basn2c08.ppm
+png2pnm.exe -noraw ..\pngsuite\basn2c16.png basn2c16.ppm
+REM -- palletted
+png2pnm.exe -noraw ..\pngsuite\basn3p01.png basn3p01.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p02.png basn3p02.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p04.png basn3p04.ppm
+png2pnm.exe -noraw ..\pngsuite\basn3p08.png basn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -noraw ..\pngsuite\basn4a08.png basn4a08.pgm
+png2pnm.exe -noraw ..\pngsuite\basn4a16.png basn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha basn6a08.pgm ..\pngsuite\basn6a08.png basn6a08.ppm
+png2pnm.exe -noraw -alpha basn6a16.pgm ..\pngsuite\basn6a16.png basn6a16.ppm
+REM -- grayscale
+png2pnm.exe -raw ..\pngsuite\basn0g01.png rawn0g01.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g02.png rawn0g02.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g04.png rawn0g04.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g08.png rawn0g08.pgm
+png2pnm.exe -raw ..\pngsuite\basn0g16.png rawn0g16.pgm
+REM -- full-color
+png2pnm.exe -raw ..\pngsuite\basn2c08.png rawn2c08.ppm
+png2pnm.exe -raw ..\pngsuite\basn2c16.png rawn2c16.ppm
+REM -- palletted
+png2pnm.exe -raw ..\pngsuite\basn3p01.png rawn3p01.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p02.png rawn3p02.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p04.png rawn3p04.ppm
+png2pnm.exe -raw ..\pngsuite\basn3p08.png rawn3p08.ppm
+REM -- gray with alpha-channel
+png2pnm.exe -raw ..\pngsuite\basn4a08.png rawn4a08.pgm
+png2pnm.exe -raw ..\pngsuite\basn4a16.png rawn4a16.pgm
+REM -- color with alpha-channel
+png2pnm.exe -noraw -alpha rawn6a08.pgm ..\pngsuite\basn6a08.png rawn6a08.ppm
+png2pnm.exe -noraw -alpha rawn6a16.pgm ..\pngsuite\basn6a16.png rawn6a16.ppm
+
diff --git a/contrib/pngminus/png2pnm.c b/contrib/pngminus/png2pnm.c
new file mode 100644
index 000000000..85321097b
--- /dev/null
+++ b/contrib/pngminus/png2pnm.c
@@ -0,0 +1,420 @@
+/*
+ * 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"
+
+/* 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;
+
+ /* 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_ptr->jmpbuf))
+ {
+ 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)
+ fprintf (pnm_file, "%ld ", ((long) *pix_ptr++ << 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)
+ fprintf (alpha_file, "%ld ", ((long) *pix_ptr++ << 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 */
+
diff --git a/contrib/pngminus/png2pnm.sh b/contrib/pngminus/png2pnm.sh
new file mode 100755
index 000000000..854313bad
--- /dev/null
+++ b/contrib/pngminus/png2pnm.sh
@@ -0,0 +1,41 @@
+# -- grayscale
+./png2pnm -noraw ../pngsuite/basn0g01.png basn0g01.pgm
+./png2pnm -noraw ../pngsuite/basn0g02.png basn0g02.pgm
+./png2pnm -noraw ../pngsuite/basn0g04.png basn0g04.pgm
+./png2pnm -noraw ../pngsuite/basn0g08.png basn0g08.pgm
+./png2pnm -noraw ../pngsuite/basn0g16.png basn0g16.pgm
+# -- full-color
+./png2pnm -noraw ../pngsuite/basn2c08.png basn2c08.ppm
+./png2pnm -noraw ../pngsuite/basn2c16.png basn2c16.ppm
+# -- palletted
+./png2pnm -noraw ../pngsuite/basn3p01.png basn3p01.ppm
+./png2pnm -noraw ../pngsuite/basn3p02.png basn3p02.ppm
+./png2pnm -noraw ../pngsuite/basn3p04.png basn3p04.ppm
+./png2pnm -noraw ../pngsuite/basn3p08.png basn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -noraw ../pngsuite/basn4a08.png basn4a08.pgm
+./png2pnm -noraw ../pngsuite/basn4a16.png basn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha basn6a08.pgm ../pngsuite/basn6a08.png basn6a08.ppm
+./png2pnm -noraw -alpha basn6a16.pgm ../pngsuite/basn6a16.png basn6a16.ppm
+# -- grayscale
+./png2pnm -raw ../pngsuite/basn0g01.png rawn0g01.pgm
+./png2pnm -raw ../pngsuite/basn0g02.png rawn0g02.pgm
+./png2pnm -raw ../pngsuite/basn0g04.png rawn0g04.pgm
+./png2pnm -raw ../pngsuite/basn0g08.png rawn0g08.pgm
+./png2pnm -raw ../pngsuite/basn0g16.png rawn0g16.pgm
+# -- full-color
+./png2pnm -raw ../pngsuite/basn2c08.png rawn2c08.ppm
+./png2pnm -raw ../pngsuite/basn2c16.png rawn2c16.ppm
+# -- palletted
+./png2pnm -raw ../pngsuite/basn3p01.png rawn3p01.ppm
+./png2pnm -raw ../pngsuite/basn3p02.png rawn3p02.ppm
+./png2pnm -raw ../pngsuite/basn3p04.png rawn3p04.ppm
+./png2pnm -raw ../pngsuite/basn3p08.png rawn3p08.ppm
+# -- gray with alpha-channel
+./png2pnm -raw ../pngsuite/basn4a08.png rawn4a08.pgm
+./png2pnm -raw ../pngsuite/basn4a16.png rawn4a16.pgm
+# -- color with alpha-channel
+./png2pnm -noraw -alpha rawn6a08.pgm ../pngsuite/basn6a08.png rawn6a08.ppm
+./png2pnm -noraw -alpha rawn6a16.pgm ../pngsuite/basn6a16.png rawn6a16.ppm
+
diff --git a/contrib/pngminus/pngminus.bat b/contrib/pngminus/pngminus.bat
new file mode 100644
index 000000000..911bb8dff
--- /dev/null
+++ b/contrib/pngminus/pngminus.bat
@@ -0,0 +1,4 @@
+make -f makefile.tc3
+call png2pnm.bat
+call pnm2png.bat
+
diff --git a/contrib/pngminus/pngminus.sh b/contrib/pngminus/pngminus.sh
new file mode 100755
index 000000000..6b2d8c5e4
--- /dev/null
+++ b/contrib/pngminus/pngminus.sh
@@ -0,0 +1,4 @@
+make -f makefile.std
+sh png2pnm.sh
+sh pnm2png.sh
+
diff --git a/contrib/pngminus/pnm2png.bat b/contrib/pngminus/pnm2png.bat
new file mode 100644
index 000000000..f756cb84d
--- /dev/null
+++ b/contrib/pngminus/pnm2png.bat
@@ -0,0 +1,41 @@
+REM -- grayscale
+pnm2png.exe basn0g01.pgm basn0g01.png
+pnm2png.exe basn0g02.pgm basn0g02.png
+pnm2png.exe basn0g04.pgm basn0g04.png
+pnm2png.exe basn0g08.pgm basn0g08.png
+pnm2png.exe basn0g16.pgm basn0g16.png
+REM -- full-color
+pnm2png.exe basn2c08.ppm basn2c08.png
+pnm2png.exe basn2c16.ppm basn2c16.png
+REM -- palletted
+pnm2png.exe basn3p01.ppm basn3p01.png
+pnm2png.exe basn3p02.ppm basn3p02.png
+pnm2png.exe basn3p04.ppm basn3p04.png
+pnm2png.exe basn3p08.ppm basn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+pnm2png.exe -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+pnm2png.exe -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+REM -- grayscale
+pnm2png.exe rawn0g01.pgm rawn0g01.png
+pnm2png.exe rawn0g02.pgm rawn0g02.png
+pnm2png.exe rawn0g04.pgm rawn0g04.png
+pnm2png.exe rawn0g08.pgm rawn0g08.png
+pnm2png.exe rawn0g16.pgm rawn0g16.png
+REM -- full-color
+pnm2png.exe rawn2c08.ppm rawn2c08.png
+pnm2png.exe rawn2c16.ppm rawn2c16.png
+REM -- palletted
+pnm2png.exe rawn3p01.ppm rawn3p01.png
+pnm2png.exe rawn3p02.ppm rawn3p02.png
+pnm2png.exe rawn3p04.ppm rawn3p04.png
+pnm2png.exe rawn3p08.ppm rawn3p08.png
+REM -- gray with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+REM -- color with alpha-channel
+pnm2png.exe -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+pnm2png.exe -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
+
diff --git a/contrib/pngminus/pnm2png.c b/contrib/pngminus/pnm2png.c
new file mode 100644
index 000000000..76533512c
--- /dev/null
+++ b/contrib/pngminus/pnm2png.c
@@ -0,0 +1,527 @@
+/*
+ * pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-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
+
+#define STDIN 0
+#define STDOUT 1
+#define STDERR 2
+
+/* to make pnm2png verbose so we can find problems (needs to be before png.h) */
+#ifndef PNG_DEBUG
+#define PNG_DEBUG 0
+#endif
+
+#include "png.h"
+
+/* function prototypes */
+
+int main (int argc, char *argv[]);
+void usage ();
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha);
+void get_token(FILE *pnm_file, char *token);
+png_uint_32 get_data (FILE *pnm_file, int depth);
+png_uint_32 get_value (FILE *pnm_file, int depth);
+
+/*
+ * main
+ */
+
+int main(int argc, char *argv[])
+{
+ FILE *fp_rd = stdin;
+ FILE *fp_al = NULL;
+ FILE *fp_wr = stdout;
+ BOOL interlace = FALSE;
+ BOOL alpha = FALSE;
+ int argi;
+
+ for (argi = 1; argi < argc; argi++)
+ {
+ if (argv[argi][0] == '-')
+ {
+ switch (argv[argi][1])
+ {
+ case 'i':
+ interlace = TRUE;
+ break;
+ case 'a':
+ alpha = TRUE;
+ argi++;
+ if ((fp_al = fopen (argv[argi], "rb")) == NULL)
+ {
+ fprintf (stderr, "PNM2PNG\n");
+ fprintf (stderr, "Error: alpha-channel file %s does not exist\n", argv[argi]);
+ exit (1);
+ }
+ break;
+ case 'h':
+ case '?':
+ usage();
+ exit(0);
+ break;
+ default:
+ fprintf (stderr, "PNM2PNG\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, "PNM2PNG\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, "PNM2PNG\n");
+ fprintf (stderr, "Error: can not create PNG-file %s\n", argv[argi]);
+ exit (1);
+ }
+ }
+ else
+ {
+ fprintf (stderr, "PNM2PNG\n");
+ fprintf (stderr, "Error: too many parameters\n");
+ usage();
+ exit (1);
+ }
+ } /* end for */
+
+#ifdef __TURBOC__
+ /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
+ if (fp_rd == stdin)
+ {
+ setmode (STDIN, O_BINARY);
+ }
+ if (fp_wr == stdout)
+ {
+ setmode (STDOUT, O_BINARY);
+ }
+#endif
+
+ /* call the conversion program itself */
+ if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
+ {
+ fprintf (stderr, "PNM2PNG\n");
+ fprintf (stderr, "Error: unsuccessful converting to 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, "PNM2PNG\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: pnm2png [options] <file>.<pnm> [<file>.png]\n");
+ fprintf (stderr, " or: ... | pnm2png [options]\n");
+ fprintf (stderr, "Options:\n");
+ fprintf (stderr, " -i[nterlace] write png-file with interlacing on\n");
+ fprintf (stderr, " -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
+ fprintf (stderr, " -h | -? print this help-information\n");
+}
+
+/*
+ * pnm2png
+ */
+
+BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace, BOOL alpha)
+{
+ png_struct *png_ptr = NULL;
+ png_info *info_ptr = NULL;
+ png_byte *png_pixels = NULL;
+ png_byte **row_pointers = NULL;
+ png_byte *pix_ptr = NULL;
+ png_uint_32 row_bytes;
+
+ char type_token[16];
+ char width_token[16];
+ char height_token[16];
+ char maxval_token[16];
+ int color_type;
+ png_uint_32 width, alpha_width;
+ png_uint_32 height, alpha_height;
+ png_uint_32 maxval;
+ int bit_depth = 0;
+ int channels;
+ int alpha_depth = 0;
+ int alpha_present;
+ int row, col;
+ BOOL raw, alpha_raw = FALSE;
+ png_uint_32 tmp16;
+ int i;
+
+ /* read header of PNM file */
+
+ get_token(pnm_file, type_token);
+ if (type_token[0] != 'P')
+ {
+ return FALSE;
+ }
+ else if ((type_token[1] == '1') || (type_token[1] == '4'))
+ {
+ raw = (type_token[1] == '4');
+ color_type = PNG_COLOR_TYPE_GRAY;
+ bit_depth = 1;
+ }
+ else if ((type_token[1] == '2') || (type_token[1] == '5'))
+ {
+ raw = (type_token[1] == '5');
+ color_type = PNG_COLOR_TYPE_GRAY;
+ get_token(pnm_file, width_token);
+ sscanf (width_token, "%lu", &width);
+ get_token(pnm_file, height_token);
+ sscanf (height_token, "%lu", &height);
+ get_token(pnm_file, maxval_token);
+ sscanf (maxval_token, "%lu", &maxval);
+ if (maxval <= 1)
+ bit_depth = 1;
+ else if (maxval <= 3)
+ bit_depth = 2;
+ else if (maxval <= 15)
+ bit_depth = 4;
+ else if (maxval <= 255)
+ bit_depth = 8;
+ else /* if (maxval <= 65535) */
+ bit_depth = 16;
+ }
+ else if ((type_token[1] == '3') || (type_token[1] == '6'))
+ {
+ raw = (type_token[1] == '6');
+ color_type = PNG_COLOR_TYPE_RGB;
+ get_token(pnm_file, width_token);
+ sscanf (width_token, "%lu", &width);
+ get_token(pnm_file, height_token);
+ sscanf (height_token, "%lu", &height);
+ get_token(pnm_file, maxval_token);
+ sscanf (maxval_token, "%lu", &maxval);
+ if (maxval <= 1)
+ bit_depth = 1;
+ else if (maxval <= 3)
+ bit_depth = 2;
+ else if (maxval <= 15)
+ bit_depth = 4;
+ else if (maxval <= 255)
+ bit_depth = 8;
+ else /* if (maxval <= 65535) */
+ bit_depth = 16;
+ }
+ else
+ {
+ return FALSE;
+ }
+
+ /* read header of PGM file with alpha channel */
+
+ if (alpha)
+ {
+ if (color_type == PNG_COLOR_TYPE_GRAY)
+ color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
+ if (color_type == PNG_COLOR_TYPE_RGB)
+ color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+
+ get_token(alpha_file, type_token);
+ if (type_token[0] != 'P')
+ {
+ return FALSE;
+ }
+ else if ((type_token[1] == '2') || (type_token[1] == '5'))
+ {
+ alpha_raw = (type_token[1] == '5');
+ get_token(alpha_file, width_token);
+ sscanf (width_token, "%lu", &alpha_width);
+ if (alpha_width != width)
+ return FALSE;
+ get_token(alpha_file, height_token);
+ sscanf (height_token, "%lu", &alpha_height);
+ if (alpha_height != height)
+ return FALSE;
+ get_token(alpha_file, maxval_token);
+ sscanf (maxval_token, "%lu", &maxval);
+ if (maxval <= 1)
+ alpha_depth = 1;
+ else if (maxval <= 3)
+ alpha_depth = 2;
+ else if (maxval <= 15)
+ alpha_depth = 4;
+ else if (maxval <= 255)
+ alpha_depth = 8;
+ else /* if (maxval <= 65535) */
+ alpha_depth = 16;
+ if (alpha_depth != bit_depth)
+ return FALSE;
+ }
+ else
+ {
+ return FALSE;
+ }
+ } /* end if alpha */
+
+ /* calculate the 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 not happen */
+
+ alpha_present = (channels - 1) % 2;
+
+ /* row_bytes is the width x number of channels x (bit-depth / 8) */
+ row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
+
+ if ((png_pixels = (png_byte *) malloc (row_bytes * height * sizeof (png_byte))) == NULL)
+ return FALSE;
+
+ /* read data from 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)
+ *pix_ptr++ = get_data (pnm_file, bit_depth);
+ else
+ if (bit_depth <= 8)
+ *pix_ptr++ = get_value (pnm_file, bit_depth);
+ else
+ {
+ tmp16 = get_value (pnm_file, bit_depth);
+ *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
+ pix_ptr++;
+ *pix_ptr = (png_byte) (tmp16 & 0xFF);
+ pix_ptr++;
+ }
+ }
+
+ if (alpha) /* read alpha-channel from pgm file */
+ {
+ if (alpha_raw)
+ *pix_ptr++ = get_data (alpha_file, alpha_depth);
+ else
+ if (alpha_depth <= 8)
+ *pix_ptr++ = get_value (alpha_file, bit_depth);
+ else
+ {
+ tmp16 = get_value (alpha_file, bit_depth);
+ *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
+ *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
+ }
+ } /* if alpha */
+
+ } /* end for col */
+ } /* end for row */
+
+ /* prepare the standard PNG structures */
+ png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+ if (!png_ptr)
+ {
+ return FALSE;
+ }
+ info_ptr = png_create_info_struct (png_ptr);
+ if (!info_ptr)
+ {
+ png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+ return FALSE;
+ }
+
+ /* setjmp() must be called in every function that calls a PNG-reading libpng function */
+ if (setjmp (png_ptr->jmpbuf))
+ {
+ png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+ return FALSE;
+ }
+
+ /* initialize the png structure */
+ png_init_io (png_ptr, png_file);
+
+ /* we're going to write more or less the same PNG as the input file */
+ png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
+ (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
+ PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+ /* write the file header information */
+ png_write_info (png_ptr, info_ptr);
+
+ /* if needed we will allocate memory for an new array of row-pointers */
+ if (row_pointers == (unsigned char**) NULL)
+ {
+ if ((row_pointers = (png_byte **) malloc (height * sizeof (png_bytep))) == NULL)
+ {
+ png_destroy_write_struct (&png_ptr, (png_infopp) 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;
+
+ /* write out the entire image data in one call */
+ png_write_image (png_ptr, row_pointers);
+
+ /* write the additional chuncks to the PNG file (not really needed) */
+ png_write_end (png_ptr, info_ptr);
+
+ /* clean up after the write, and free any memory allocated */
+ png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
+
+ if (row_pointers != (unsigned char**) NULL)
+ free (row_pointers);
+ if (png_pixels != (unsigned char*) NULL)
+ free (png_pixels);
+
+ return TRUE;
+} /* end of pnm2png */
+
+/*
+ * get_token() - gets the first string after whitespace
+ */
+
+void get_token(FILE *pnm_file, char *token)
+{
+ int i = 0;
+
+ /* remove white-space */
+ do
+ {
+ token[i] = (unsigned char) fgetc (pnm_file);
+ }
+ while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
+
+ /* read string */
+ do
+ {
+ i++;
+ token[i] = (unsigned char) fgetc (pnm_file);
+ }
+ while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
+
+ token[i] = '\0';
+
+ return;
+}
+
+/*
+ * get_data() - takes first byte and converts into next pixel value,
+ * taking as much bits as defined by bit-depth and
+ * using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+
+png_uint_32 get_data (FILE *pnm_file, int depth)
+{
+ static int bits_left = 0;
+ static int old_value = 0;
+ static int mask = 0;
+ int i;
+ png_uint_32 ret_value;
+
+ if (mask == 0)
+ for (i = 0; i < depth; i++)
+ mask = (mask >> 1) | 0x80;
+
+ if (bits_left <= 0)
+ {
+ old_value = fgetc (pnm_file);
+ bits_left = 8;
+ }
+
+ ret_value = old_value & mask;
+ for (i = 1; i < (8 / depth); i++)
+ ret_value = ret_value || (ret_value >> depth);
+
+ old_value = (old_value << depth) & 0xFF;
+ bits_left -= depth;
+
+ return ret_value;
+}
+
+/*
+ * get_value() - takes first (numeric) string and converts into number,
+ * using the bit-depth to fill up a byte (0Ah -> AAh)
+ */
+
+png_uint_32 get_value (FILE *pnm_file, int depth)
+{
+ static png_uint_32 mask = 0;
+ png_byte token[16];
+ png_uint_32 ret_value;
+ int i = 0;
+
+ if (mask == 0)
+ for (i = 0; i < depth; i++)
+ mask = (mask << 1) | 0x01;
+
+ get_token (pnm_file, token);
+ sscanf (token, "%lu", &ret_value);
+
+ ret_value &= mask;
+
+ if (depth < 8)
+ for (i = 0; i < (8 / depth); i++)
+ ret_value = (ret_value << depth) || ret_value;
+
+ return ret_value;
+}
+
+/* end of source */
+
diff --git a/contrib/pngminus/pnm2png.sh b/contrib/pngminus/pnm2png.sh
new file mode 100755
index 000000000..5afda9fb9
--- /dev/null
+++ b/contrib/pngminus/pnm2png.sh
@@ -0,0 +1,41 @@
+# -- grayscale
+./pnm2png basn0g01.pgm basn0g01.png
+./pnm2png basn0g02.pgm basn0g02.png
+./pnm2png basn0g04.pgm basn0g04.png
+./pnm2png basn0g08.pgm basn0g08.png
+./pnm2png basn0g16.pgm basn0g16.png
+# -- full-color
+./pnm2png basn2c08.ppm basn2c08.png
+./pnm2png basn2c16.ppm basn2c16.png
+# -- palletted
+./pnm2png basn3p01.ppm basn3p01.png
+./pnm2png basn3p02.ppm basn3p02.png
+./pnm2png basn3p04.ppm basn3p04.png
+./pnm2png basn3p08.ppm basn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn4a08.pgm basn4a08.png
+./pnm2png -alpha basn6a16.pgm basn4a16.pgm basn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha basn6a08.pgm basn6a08.ppm basn6a08.png
+./pnm2png -alpha basn6a16.pgm basn6a16.ppm basn6a16.png
+# -- grayscale
+./pnm2png rawn0g01.pgm rawn0g01.png
+./pnm2png rawn0g02.pgm rawn0g02.png
+./pnm2png rawn0g04.pgm rawn0g04.png
+./pnm2png rawn0g08.pgm rawn0g08.png
+./pnm2png rawn0g16.pgm rawn0g16.png
+# -- full-color
+./pnm2png rawn2c08.ppm rawn2c08.png
+./pnm2png rawn2c16.ppm rawn2c16.png
+# -- palletted
+./pnm2png rawn3p01.ppm rawn3p01.png
+./pnm2png rawn3p02.ppm rawn3p02.png
+./pnm2png rawn3p04.ppm rawn3p04.png
+./pnm2png rawn3p08.ppm rawn3p08.png
+# -- gray with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn4a08.pgm rawn4a08.png
+./pnm2png -alpha rawn6a16.pgm rawn4a16.pgm rawn4a16.png
+# -- color with alpha-channel
+./pnm2png -alpha rawn6a08.pgm rawn6a08.ppm rawn6a08.png
+./pnm2png -alpha rawn6a16.pgm rawn6a16.ppm rawn6a16.png
+