src/tiff/tools/sgi2tiff.c

/* $Id$ */

/*
 * Copyright (c) 1991-1997 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <gl/image.h>
#include <ctype.h>

#include "tiffio.h"

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

static	short config = PLANARCONFIG_CONTIG;
static	uint16 compression = COMPRESSION_PACKBITS;
static	uint16 predictor = 0;
static	uint16 fillorder = 0;
static	uint32 rowsperstrip = (uint32) -1;
static	int jpegcolormode = JPEGCOLORMODE_RGB;
static	int quality = 75;		/* JPEG quality */
static	uint16 photometric;

static	void usage(void);
static	int cpContig(IMAGE*, TIFF*);
static	int cpSeparate(IMAGE*, TIFF*);
static	int processCompressOptions(char*);

/* XXX image library has no prototypes */
extern	IMAGE* iopen(const char*, const char*);
extern	void iclose(IMAGE*);
extern	void getrow(IMAGE*, short*, int, int);

int
main(int argc, char* argv[])
{
	IMAGE *in;
	TIFF *out;
	int c;
	extern int optind;
	extern char* optarg;

	while ((c = getopt(argc, argv, "c:p:r:")) != -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 'p':		/* planar configuration */
			if (streq(optarg, "separate"))
				config = PLANARCONFIG_SEPARATE;
			else if (streq(optarg, "contig"))
				config = PLANARCONFIG_CONTIG;
			else
				usage();
			break;
		case 'r':		/* rows/strip */
			rowsperstrip = atoi(optarg);
			break;
		case '?':
			usage();
			/*NOTREACHED*/
		}
	if (argc - optind != 2)
		usage();
	in = iopen(argv[optind], "r");
	if (in == NULL)
		return (-1);
	out = TIFFOpen(argv[optind+1], "w");
	if (out == NULL)
		return (-2);
	TIFFSetField(out, TIFFTAG_IMAGEWIDTH, (uint32) in->xsize);
	TIFFSetField(out, TIFFTAG_IMAGELENGTH, (uint32) in->ysize);
	TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, 8);
	TIFFSetField(out, TIFFTAG_COMPRESSION, compression);
	if (in->zsize == 1)
		photometric = PHOTOMETRIC_MINISBLACK;
	else
		photometric = PHOTOMETRIC_RGB;
	switch (compression) {
	case COMPRESSION_JPEG:
		if (photometric == PHOTOMETRIC_RGB && jpegcolormode == JPEGCOLORMODE_RGB)
			photometric = PHOTOMETRIC_YCBCR;
		TIFFSetField(out, TIFFTAG_JPEGQUALITY, quality);
		TIFFSetField(out, TIFFTAG_JPEGCOLORMODE, jpegcolormode);
		break;
	case COMPRESSION_LZW:
	case COMPRESSION_DEFLATE:
		if (predictor != 0)
			TIFFSetField(out, TIFFTAG_PREDICTOR, predictor);
		break;
	}
	TIFFSetField(out, TIFFTAG_PHOTOMETRIC, photometric);
	if (fillorder != 0)
		TIFFSetField(out, TIFFTAG_FILLORDER, fillorder);
	TIFFSetField(out, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
	TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, in->zsize);
	if (in->zsize > 3) {
	    uint16 v[1];
	    v[0] = EXTRASAMPLE_UNASSALPHA;
	    TIFFSetField(out, TIFFTAG_EXTRASAMPLES, 1, v);
	}
	TIFFSetField(out, TIFFTAG_MINSAMPLEVALUE, (uint16) in->min);
	TIFFSetField(out, TIFFTAG_MAXSAMPLEVALUE, (uint16) in->max);
	TIFFSetField(out, TIFFTAG_PLANARCONFIG, config);
	if (config != PLANARCONFIG_SEPARATE)
		TIFFSetField(out, TIFFTAG_ROWSPERSTRIP,
		    TIFFDefaultStripSize(out, rowsperstrip));
	else			/* force 1 row/strip for library limitation */
		TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, 1L);
	if (in->name[0] != '\0')
		TIFFSetField(out, TIFFTAG_IMAGEDESCRIPTION, in->name);
	if (config == PLANARCONFIG_CONTIG)
		cpContig(in, out);
	else
		cpSeparate(in, out);
	(void) iclose(in);
	(void) TIFFClose(out);
	return (0);
}

static int
processCompressOptions(char* opt)
{
	if (streq(opt, "none"))
		compression = COMPRESSION_NONE;
	else if (streq(opt, "packbits"))
		compression = COMPRESSION_PACKBITS;
	else if (strneq(opt, "jpeg", 4)) {
		char* cp = strchr(opt, ':');

                defcompression = COMPRESSION_JPEG;
                while( cp )
                {
                    if (isdigit((int)cp[1]))
			quality = atoi(cp+1);
                    else if (cp[1] == 'r' )
			jpegcolormode = JPEGCOLORMODE_RAW;
                    else
                        usage();

                    cp = strchr(cp+1,':');
                }
	} 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);
}

static int
cpContig(IMAGE* in, TIFF* out)
{
	tdata_t buf = _TIFFmalloc(TIFFScanlineSize(out));
	short *r = NULL;
	int x, y;

	if (in->zsize == 3) {
		short *g, *b;

		r = (short *)_TIFFmalloc(3 * in->xsize * sizeof (short));
		g = r + in->xsize;
		b = g + in->xsize;
		for (y = in->ysize-1; y >= 0; y--) {
			uint8* pp = (uint8*) buf;

			getrow(in, r, y, 0);
			getrow(in, g, y, 1);
			getrow(in, b, y, 2);
			for (x = 0; x < in->xsize; x++) {
				pp[0] = r[x];
				pp[1] = g[x];
				pp[2] = b[x];
				pp += 3;
			}
			if (TIFFWriteScanline(out, buf, in->ysize-y-1, 0) < 0)
				goto bad;
		}
	} else if (in->zsize == 4) {
		short *g, *b, *a;

		r = (short *)_TIFFmalloc(4 * in->xsize * sizeof (short));
		g = r + in->xsize;
		b = g + in->xsize;
		a = b + in->xsize;
		for (y = in->ysize-1; y >= 0; y--) {
			uint8* pp = (uint8*) buf;

			getrow(in, r, y, 0);
			getrow(in, g, y, 1);
			getrow(in, b, y, 2);
			getrow(in, a, y, 3);
			for (x = 0; x < in->xsize; x++) {
				pp[0] = r[x];
				pp[1] = g[x];
				pp[2] = b[x];
				pp[3] = a[x];
				pp += 4;
			}
			if (TIFFWriteScanline(out, buf, in->ysize-y-1, 0) < 0)
				goto bad;
		}
	} else {
		uint8* pp = (uint8*) buf;

		r = (short *)_TIFFmalloc(in->xsize * sizeof (short));
		for (y = in->ysize-1; y >= 0; y--) {
			getrow(in, r, y, 0);
			for (x = in->xsize-1; x >= 0; x--)
				pp[x] = r[x];
			if (TIFFWriteScanline(out, buf, in->ysize-y-1, 0) < 0)
				goto bad;
		}
	}
	if (r)
		_TIFFfree(r);
	_TIFFfree(buf);
	return (1);
bad:
	if (r)
		_TIFFfree(r);
	_TIFFfree(buf);
	return (0);
}

static int
cpSeparate(IMAGE* in, TIFF* out)
{
	tdata_t buf = _TIFFmalloc(TIFFScanlineSize(out));
	short *r = (short *)_TIFFmalloc(in->xsize * sizeof (short));
	uint8* pp = (uint8*) buf;
	int x, y, z;

	for (z = 0; z < in->zsize; z++) {
		for (y = in->ysize-1; y >= 0; y--) {
			getrow(in, r, y, z);
			for (x = 0; x < in->xsize; x++)
				pp[x] = r[x];
			if (TIFFWriteScanline(out, buf, in->ysize-y-1, z) < 0)
				goto bad;
		}
	}
	_TIFFfree(r);
	_TIFFfree(buf);
	return (1);
bad:
	_TIFFfree(r);
	_TIFFfree(buf);
	return (0);
}

char* stuff[] = {
"usage: sgi2tiff [options] input.rgb output.tif",
"where options are:",
" -r #		make each strip have no more than # rows",
"",
" -p contig	pack samples contiguously (e.g. RGBRGB...)",
" -p separate	store samples separately (e.g. RRR...GGG...BBB...)",
"",
" -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 jpeg[:opts]compress output with JPEG encoding",
" -c packbits	compress output with packbits encoding",
" -c none	use no compression algorithm on output",
"",
"JPEG options:",
" #		set compression quality level (0-100, default 75)",
" r		output color image as RGB rather than YCbCr",
"",
"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);
	for (i = 0; stuff[i] != NULL; i++)
		fprintf(stderr, "%s\n", stuff[i]);
	exit(-1);
}
Commit	Line	Data
	1	/* $Id$ */
	2
	3	/*
	4	* Copyright (c) 1991-1997 Sam Leffler
	5	* Copyright (c) 1991-1997 Silicon Graphics, Inc.
	6	*
	7	* Permission to use, copy, modify, distribute, and sell this software and
	8	* its documentation for any purpose is hereby granted without fee, provided
	9	* that (i) the above copyright notices and this permission notice appear in
	10	* all copies of the software and related documentation, and (ii) the names of
	11	* Sam Leffler and Silicon Graphics may not be used in any advertising or
	12	* publicity relating to the software without the specific, prior written
	13	* permission of Sam Leffler and Silicon Graphics.
	14	*
	15	* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
	16	* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
	17	* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
	18	*
	19	* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
	20	* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
	21	* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
	22	* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
	23	* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
	24	* OF THIS SOFTWARE.
	25	*/
	26
	27	#include <stdio.h>
	28	#include <stdlib.h>
	29	#include <string.h>
	30	#include <gl/image.h>
	31	#include <ctype.h>
	32
	33	#include "tiffio.h"
	34
	35	#define streq(a,b) (strcmp(a,b) == 0)
	36	#define strneq(a,b,n) (strncmp(a,b,n) == 0)
	37
	38	static short config = PLANARCONFIG_CONTIG;
	39	static uint16 compression = COMPRESSION_PACKBITS;
	40	static uint16 predictor = 0;
	41	static uint16 fillorder = 0;
	42	static uint32 rowsperstrip = (uint32) -1;
	43	static int jpegcolormode = JPEGCOLORMODE_RGB;
	44	static int quality = 75; /* JPEG quality */
	45	static uint16 photometric;
	46
	47	static void usage(void);
	48	static int cpContig(IMAGE, TIFF);
	49	static int cpSeparate(IMAGE, TIFF);
	50	static int processCompressOptions(char*);
	51
	52	/* XXX image library has no prototypes */
	53	extern IMAGE* iopen(const char, const char);
	54	extern void iclose(IMAGE*);
	55	extern void getrow(IMAGE, short, int, int);
	56
	57	int
	58	main(int argc, char* argv[])
	59	{
	60	IMAGE *in;
	61	TIFF *out;
	62	int c;
	63	extern int optind;
	64	extern char* optarg;
	65
	66	while ((c = getopt(argc, argv, "c:p:r:")) != -1)
	67	switch (c) {
	68	case 'c': /* compression scheme */
	69	if (!processCompressOptions(optarg))
	70	usage();
	71	break;
	72	case 'f': /* fill order */
	73	if (streq(optarg, "lsb2msb"))
	74	fillorder = FILLORDER_LSB2MSB;
	75	else if (streq(optarg, "msb2lsb"))
	76	fillorder = FILLORDER_MSB2LSB;
	77	else
	78	usage();
	79	break;
	80	case 'p': /* planar configuration */
	81	if (streq(optarg, "separate"))
	82	config = PLANARCONFIG_SEPARATE;
	83	else if (streq(optarg, "contig"))
	84	config = PLANARCONFIG_CONTIG;
	85	else
	86	usage();
	87	break;
	88	case 'r': /* rows/strip */
	89	rowsperstrip = atoi(optarg);
	90	break;
	91	case '?':
	92	usage();
	93	/NOTREACHED/
	94	}
	95	if (argc - optind != 2)
	96	usage();
	97	in = iopen(argv[optind], "r");
	98	if (in == NULL)
	99	return (-1);
	100	out = TIFFOpen(argv[optind+1], "w");
	101	if (out == NULL)
	102	return (-2);
	103	TIFFSetField(out, TIFFTAG_IMAGEWIDTH, (uint32) in->xsize);
	104	TIFFSetField(out, TIFFTAG_IMAGELENGTH, (uint32) in->ysize);
	105	TIFFSetField(out, TIFFTAG_BITSPERSAMPLE, 8);
	106	TIFFSetField(out, TIFFTAG_COMPRESSION, compression);
	107	if (in->zsize == 1)
	108	photometric = PHOTOMETRIC_MINISBLACK;
	109	else
	110	photometric = PHOTOMETRIC_RGB;
	111	switch (compression) {
	112	case COMPRESSION_JPEG:
	113	if (photometric == PHOTOMETRIC_RGB && jpegcolormode == JPEGCOLORMODE_RGB)
	114	photometric = PHOTOMETRIC_YCBCR;
	115	TIFFSetField(out, TIFFTAG_JPEGQUALITY, quality);
	116	TIFFSetField(out, TIFFTAG_JPEGCOLORMODE, jpegcolormode);
	117	break;
	118	case COMPRESSION_LZW:
	119	case COMPRESSION_DEFLATE:
	120	if (predictor != 0)
	121	TIFFSetField(out, TIFFTAG_PREDICTOR, predictor);
	122	break;
	123	}
	124	TIFFSetField(out, TIFFTAG_PHOTOMETRIC, photometric);
	125	if (fillorder != 0)
	126	TIFFSetField(out, TIFFTAG_FILLORDER, fillorder);
	127	TIFFSetField(out, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
	128	TIFFSetField(out, TIFFTAG_SAMPLESPERPIXEL, in->zsize);
	129	if (in->zsize > 3) {
	130	uint16 v[1];
	131	v[0] = EXTRASAMPLE_UNASSALPHA;
	132	TIFFSetField(out, TIFFTAG_EXTRASAMPLES, 1, v);
	133	}
	134	TIFFSetField(out, TIFFTAG_MINSAMPLEVALUE, (uint16) in->min);
	135	TIFFSetField(out, TIFFTAG_MAXSAMPLEVALUE, (uint16) in->max);
	136	TIFFSetField(out, TIFFTAG_PLANARCONFIG, config);
	137	if (config != PLANARCONFIG_SEPARATE)
	138	TIFFSetField(out, TIFFTAG_ROWSPERSTRIP,
	139	TIFFDefaultStripSize(out, rowsperstrip));
	140	else /* force 1 row/strip for library limitation */
	141	TIFFSetField(out, TIFFTAG_ROWSPERSTRIP, 1L);
	142	if (in->name[0] != '\0')
	143	TIFFSetField(out, TIFFTAG_IMAGEDESCRIPTION, in->name);
	144	if (config == PLANARCONFIG_CONTIG)
	145	cpContig(in, out);
	146	else
	147	cpSeparate(in, out);
	148	(void) iclose(in);
	149	(void) TIFFClose(out);
	150	return (0);
	151	}
	152
	153	static int
	154	processCompressOptions(char* opt)
	155	{
	156	if (streq(opt, "none"))
	157	compression = COMPRESSION_NONE;
	158	else if (streq(opt, "packbits"))
	159	compression = COMPRESSION_PACKBITS;
	160	else if (strneq(opt, "jpeg", 4)) {
	161	char* cp = strchr(opt, ':');
	162
	163	defcompression = COMPRESSION_JPEG;
	164	while( cp )
	165	{
	166	if (isdigit((int)cp[1]))
	167	quality = atoi(cp+1);
	168	else if (cp[1] == 'r' )
	169	jpegcolormode = JPEGCOLORMODE_RAW;
	170	else
	171	usage();
	172
	173	cp = strchr(cp+1,':');
	174	}
	175	} else if (strneq(opt, "lzw", 3)) {
	176	char* cp = strchr(opt, ':');
	177	if (cp)
	178	predictor = atoi(cp+1);
	179	compression = COMPRESSION_LZW;
	180	} else if (strneq(opt, "zip", 3)) {
	181	char* cp = strchr(opt, ':');
	182	if (cp)
	183	predictor = atoi(cp+1);
	184	compression = COMPRESSION_DEFLATE;
	185	} else
	186	return (0);
	187	return (1);
	188	}
	189
	190	static int
	191	cpContig(IMAGE* in, TIFF* out)
	192	{
	193	tdata_t buf = _TIFFmalloc(TIFFScanlineSize(out));
	194	short *r = NULL;
	195	int x, y;
	196
	197	if (in->zsize == 3) {
	198	short g, b;
	199
	200	r = (short )_TIFFmalloc(3 in->xsize * sizeof (short));
	201	g = r + in->xsize;
	202	b = g + in->xsize;
	203	for (y = in->ysize-1; y >= 0; y--) {
	204	uint8* pp = (uint8*) buf;
	205
	206	getrow(in, r, y, 0);
	207	getrow(in, g, y, 1);
	208	getrow(in, b, y, 2);
	209	for (x = 0; x < in->xsize; x++) {
	210	pp[0] = r[x];
	211	pp[1] = g[x];
	212	pp[2] = b[x];
	213	pp += 3;
	214	}
	215	if (TIFFWriteScanline(out, buf, in->ysize-y-1, 0) < 0)
	216	goto bad;
	217	}
	218	} else if (in->zsize == 4) {
	219	short g, b, *a;
	220
	221	r = (short )_TIFFmalloc(4 in->xsize * sizeof (short));
	222	g = r + in->xsize;
	223	b = g + in->xsize;
	224	a = b + in->xsize;
	225	for (y = in->ysize-1; y >= 0; y--) {
	226	uint8* pp = (uint8*) buf;
	227
	228	getrow(in, r, y, 0);
	229	getrow(in, g, y, 1);
	230	getrow(in, b, y, 2);
	231	getrow(in, a, y, 3);
	232	for (x = 0; x < in->xsize; x++) {
	233	pp[0] = r[x];
	234	pp[1] = g[x];
	235	pp[2] = b[x];
	236	pp[3] = a[x];
	237	pp += 4;
	238	}
	239	if (TIFFWriteScanline(out, buf, in->ysize-y-1, 0) < 0)
	240	goto bad;
	241	}
	242	} else {
	243	uint8* pp = (uint8*) buf;
	244
	245	r = (short )_TIFFmalloc(in->xsize sizeof (short));
	246	for (y = in->ysize-1; y >= 0; y--) {
	247	getrow(in, r, y, 0);
	248	for (x = in->xsize-1; x >= 0; x--)
	249	pp[x] = r[x];
	250	if (TIFFWriteScanline(out, buf, in->ysize-y-1, 0) < 0)
	251	goto bad;
	252	}
	253	}
	254	if (r)
	255	_TIFFfree(r);
	256	_TIFFfree(buf);
	257	return (1);
	258	bad:
	259	if (r)
	260	_TIFFfree(r);
	261	_TIFFfree(buf);
	262	return (0);
	263	}
	264
	265	static int
	266	cpSeparate(IMAGE* in, TIFF* out)
	267	{
	268	tdata_t buf = _TIFFmalloc(TIFFScanlineSize(out));
	269	short r = (short )_TIFFmalloc(in->xsize * sizeof (short));
	270	uint8* pp = (uint8*) buf;
	271	int x, y, z;
	272
	273	for (z = 0; z < in->zsize; z++) {
	274	for (y = in->ysize-1; y >= 0; y--) {
	275	getrow(in, r, y, z);
	276	for (x = 0; x < in->xsize; x++)
	277	pp[x] = r[x];
	278	if (TIFFWriteScanline(out, buf, in->ysize-y-1, z) < 0)
	279	goto bad;
	280	}
	281	}
	282	_TIFFfree(r);
	283	_TIFFfree(buf);
	284	return (1);
	285	bad:
	286	_TIFFfree(r);
	287	_TIFFfree(buf);
	288	return (0);
	289	}
	290
	291	char* stuff[] = {
	292	"usage: sgi2tiff [options] input.rgb output.tif",
	293	"where options are:",
	294	" -r # make each strip have no more than # rows",
	295	"",
	296	" -p contig pack samples contiguously (e.g. RGBRGB...)",
	297	" -p separate store samples separately (e.g. RRR...GGG...BBB...)",
	298	"",
	299	" -f lsb2msb force lsb-to-msb FillOrder for output",
	300	" -f msb2lsb force msb-to-lsb FillOrder for output",
	301	"",
	302	" -c lzw[:opts] compress output with Lempel-Ziv & Welch encoding",
	303	" -c zip[:opts] compress output with deflate encoding",
	304	" -c jpeg[:opts]compress output with JPEG encoding",
	305	" -c packbits compress output with packbits encoding",
	306	" -c none use no compression algorithm on output",
	307	"",
	308	"JPEG options:",
	309	" # set compression quality level (0-100, default 75)",
	310	" r output color image as RGB rather than YCbCr",
	311	"",
	312	"LZW and deflate options:",
	313	" # set predictor value",
	314	"For example, -c lzw:2 to get LZW-encoded data with horizontal differencing",
	315	NULL
	316	};
	317
	318	static void
	319	usage(void)
	320	{
	321	char buf[BUFSIZ];
	322	int i;
	323
	324	setbuf(stderr, buf);
	325	for (i = 0; stuff[i] != NULL; i++)
	326	fprintf(stderr, "%s\n", stuff[i]);
	327	exit(-1);
	328	}