/* $Id: tiffdither.c,v 1.12 2010-03-10 18:56:50 bfriesen Exp $ */

/*

 * Copyright (c) 1988-1997 Sam Leffler

 * Copyright (c) 1991-1997 Silicon Graphics, Inc.

 *

 * Permission to use, copy, modify, distribute, and sell this software and 

 * its documentation for any purpose is hereby granted without fee, provided

 * that (i) the above copyright notices and this permission notice appear in

 * all copies of the software and related documentation, and (ii) the names of

 * Sam Leffler and Silicon Graphics may not be used in any advertising or

 * publicity relating to the software without the specific, prior written

 * permission of Sam Leffler and Silicon Graphics.

 * 

 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 

 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 

 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  

 * 

 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR

 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,

 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,

 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 

 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 

 * OF THIS SOFTWARE.

 */

#include "tif_config.h"

#include <stdio.h></stdio.h>

#include <stdlib.h></stdlib.h>

#include <string.h></string.h>

#ifdef HAVE_UNISTD_H

# include <unistd.h></unistd.h>

#endif

#ifdef NEED_LIBPORT

# include "libport.h"

#endif

#include "tiffio.h"

#define	streq(a,b)	(strcmp(a,b) == 0)

#define	strneq(a,b,n)	(strncmp(a,b,n) == 0)

#define	CopyField(tag, v) \

	if (TIFFGetField(in, tag, &v)) TIFFSetField(out, tag, v)

uint32	imagewidth;

uint32	imagelength;

int	threshold = 128;

static	void usage(void);

/* 

 * Floyd-Steinberg error propragation with threshold.

 * This code is stolen from tiffmedian.

 */

static void

fsdither(TIFF* in, TIFF* out)

{

	unsigned char *outline, *inputline, *inptr;

	short *thisline, *nextline, *tmpptr;

	register unsigned char	*outptr;

	register short *thisptr, *nextptr;

	register uint32 i, j;

	uint32 imax, jmax;

	int lastline, lastpixel;

	int bit;

	tsize_t outlinesize;

	imax = imagelength - 1;

	jmax = imagewidth - 1;

	inputline = (unsigned char *)_TIFFmalloc(TIFFScanlineSize(in));

	thisline = (short *)_TIFFmalloc(imagewidth * sizeof (short));

	nextline = (short *)_TIFFmalloc(imagewidth * sizeof (short));

	outlinesize = TIFFScanlineSize(out);

	outline = (unsigned char *) _TIFFmalloc(outlinesize);

	/*

	 * Get first line

	 */

	if (TIFFReadScanline(in, inputline, 0, 0) <= 0)

            goto skip_on_error;

	inptr = inputline;

	nextptr = nextline;

	for (j = 0; j < imagewidth; ++j)

		*nextptr++ = *inptr++;

	for (i = 1; i < imagelength; ++i) {

		tmpptr = thisline;

		thisline = nextline;

		nextline = tmpptr;

		lastline = (i == imax);

		if (TIFFReadScanline(in, inputline, i, 0) <= 0)

			break;

		inptr = inputline;

		nextptr = nextline;

		for (j = 0; j < imagewidth; ++j)

			*nextptr++ = *inptr++;

		thisptr = thisline;

		nextptr = nextline;

		_TIFFmemset(outptr = outline, 0, outlinesize);

		bit = 0x80;

		for (j = 0; j < imagewidth; ++j) {

			register int v;

			lastpixel = (j == jmax);

			v = *thisptr++;

			if (v < 0)

				v = 0;

			else if (v > 255)

				v = 255;

			if (v > threshold) {

				*outptr |= bit;

				v -= 255;

			}

			bit >>= 1;

			if (bit == 0) {

				outptr++;

				bit = 0x80;

			}

			if (!lastpixel)

				thisptr[0] += v * 7 / 16;

			if (!lastline) {

				if (j != 0)

					nextptr[-1] += v * 3 / 16;

				*nextptr++ += v * 5 / 16;

				if (!lastpixel)

					nextptr[0] += v / 16;

			}

		}

		if (TIFFWriteScanline(out, outline, i-1, 0) < 0)

			break;

	}

  skip_on_error:

	_TIFFfree(inputline);

	_TIFFfree(thisline);

	_TIFFfree(nextline);

	_TIFFfree(outline);

}

static	uint16 compression = COMPRESSION_PACKBITS;

static	uint16 predictor = 0;

static	uint32 group3options = 0;

static void

processG3Options(char* cp)

{

	if ((cp = strchr(cp, ':'))) {

		do {

			cp++;

			if (strneq(cp, "1d", 2))

				group3options &= ~GROUP3OPT_2DENCODING;

			else if (strneq(cp, "2d", 2))

				group3options |= GROUP3OPT_2DENCODING;

			else if (strneq(cp, "fill", 4))

				group3options |= GROUP3OPT_FILLBITS;

			else

				usage();

		} while ((cp = strchr(cp, ':')));

	}

}

static int

processCompressOptions(char* opt)

{

	if (streq(opt, "none"))

		compression = COMPRESSION_NONE;

	else if (streq(opt, "packbits"))

		compression = COMPRESSION_PACKBITS;

	else if (strneq(opt, "g3", 2)) {

		processG3Options(opt);

		compression = COMPRESSION_CCITTFAX3;

	} else if (streq(opt, "g4"))

		compression = COMPRESSION_CCITTFAX4;

	else if (strneq(opt, "lzw", 3)) {

		char* cp = strchr(opt, ':');

		if (cp)

			predictor = atoi(cp+1);

		compression = COMPRESSION_LZW;

	} else if (strneq(opt, "zip", 3)) {

		char* cp = strchr(opt, ':');

		if (cp)

			predictor = atoi(cp+1);

		compression = COMPRESSION_DEFLATE;

	} else

		return (0);

	return (1);

}

int

main(int argc, char* argv[])

{

	TIFF *in, *out;

	uint16 samplesperpixel, bitspersample = 1, shortv;

	float floatv;

	char thing[1024];

	uint32 rowsperstrip = (uint32) -1;

	uint16 fillorder = 0;

	int c;

	extern int optind;

	extern char *optarg;

	while ((c = getopt(argc, argv, "c:f:r:t:")) != -1)

		switch (c) {

		case 'c':		/* compression scheme */

			if (!processCompressOptions(optarg))

				usage();

			break;

		case 'f':		/* fill order */

			if (streq(optarg, "lsb2msb"))

				fillorder = FILLORDER_LSB2MSB;

			else if (streq(optarg, "msb2lsb"))

				fillorder = FILLORDER_MSB2LSB;

			else

				usage();

			break;

		case 'r':		/* rows/strip */

			rowsperstrip = atoi(optarg);

			break;

		case 't':

			threshold = atoi(optarg);

			if (threshold < 0)

				threshold = 0;

			else if (threshold > 255)

				threshold = 255;

			break;

		case '?':

			usage();

			/*NOTREACHED*/

		}

	if (argc - optind < 2)

		usage();

	in = TIFFOpen(argv[optind], "r");

	if (in == NULL)

		return (-1);

	TIFFGetField(in, TIFFTAG_SAMPLESPERPIXEL, &samplesperpixel);

	if (samplesperpixel != 1) {

		fprintf(stderr, "%s: Not a b&w image.\n", argv[0]);

		return (-1);

	}

	TIFFGetField(in, TIFFTAG_BITSPERSAMPLE, &bitspersample);

	if (bitspersample != 8) {

		fprintf(stderr,

		    " %s: Sorry, only handle 8-bit samples.\n", argv[0]);

		return (-1);

	}

	out = TIFFOpen(argv[optind+1], "w");

	if (out == NULL)

		return (-1);

	CopyField(TIFFTAG_IMAGEWIDTH, imagewidth);

	TIFFGetField(in, TIFFTAG_IMAGELENGTH, &imagelength);

	TIFFSetField(out, TIFFTAG_IMAGELENGTH, imagelength-1);

	TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, 1);

	TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, 1);

	TIFFSetField(out, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);

	TIFFSetField(out, TIFFTAG_COMPRESSION, compression);

	if (fillorder)

		TIFFSetField(out, TIFFTAG_FILLORDER, fillorder);

	else

		CopyField(TIFFTAG_FILLORDER, shortv);

	sprintf(thing, "Dithered B&W version of %s", argv[optind]);

	TIFFSetField(out, TIFFTAG_IMAGEDESCRIPTION, thing);

	CopyField(TIFFTAG_PHOTOMETRIC, shortv);

	CopyField(TIFFTAG_ORIENTATION, shortv);

	CopyField(TIFFTAG_XRESOLUTION, floatv);

	CopyField(TIFFTAG_YRESOLUTION, floatv);

	CopyField(TIFFTAG_RESOLUTIONUNIT, shortv);

        rowsperstrip = TIFFDefaultStripSize(out, rowsperstrip);

	TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, rowsperstrip);

	switch (compression) {

	case COMPRESSION_CCITTFAX3:

		TIFFSetField(out, TIFFTAG_GROUP3OPTIONS, group3options);

		break;

	case COMPRESSION_LZW:

	case COMPRESSION_DEFLATE:

		if (predictor)

			TIFFSetField(out, TIFFTAG_PREDICTOR, predictor);

		break;

	}

	fsdither(in, out);

	TIFFClose(in);

	TIFFClose(out);

	return (0);

}

char* stuff[] = {

"usage: tiffdither [options] input.tif output.tif",

"where options are:",

" -r #		make each strip have no more than # rows",

" -f lsb2msb	force lsb-to-msb FillOrder for output",

" -f msb2lsb	force msb-to-lsb FillOrder for output",

" -c lzw[:opts]	compress output with Lempel-Ziv & Welch encoding",

" -c zip[:opts]	compress output with deflate encoding",

" -c packbits	compress output with packbits encoding",

" -c g3[:opts]	compress output with CCITT Group 3 encoding",

" -c g4		compress output with CCITT Group 4 encoding",

" -c none	use no compression algorithm on output",

"",

"Group 3 options:",

" 1d		use default CCITT Group 3 1D-encoding",

" 2d		use optional CCITT Group 3 2D-encoding",

" fill		byte-align EOL codes",

"For example, -c g3:2d:fill to get G3-2D-encoded data with byte-aligned EOLs",

"",

"LZW and deflate options:",

" #		set predictor value",

"For example, -c lzw:2 to get LZW-encoded data with horizontal differencing",

NULL

};

static void

usage(void)

{

	char buf[BUFSIZ];

	int i;

	setbuf(stderr, buf);

        fprintf(stderr, "%s\n\n", TIFFGetVersion());

	for (i = 0; stuff[i] != NULL; i++)

		fprintf(stderr, "%s\n", stuff[i]);

	exit(-1);

}

/* vim: set ts=8 sts=8 sw=8 noet: */

/*

 * Local Variables:

 * mode: c

 * c-basic-offset: 8

 * fill-column: 78

 * End:

 */