[wxWidgets.git] / src / tiff / tools / gif2tiff.c

/* $Id$ */

/*
 * Copyright (c) 1990-1997 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.
 */

/*
 *	convert a GIF file into a TIFF file.
 *	based on Paul Haeberli's fromgif program which in turn is
 *	based on a GIF file reader by Marcel J.E. Mol March 23 1989 
 *
 *	if input is 320 by 200 pixel aspect is probably 1.2
 *	if input is 640 350 pixel aspect is probably 1.37
 *
 */
#include "tif_config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#include "tiffio.h"

#define	GIFGAMMA	(1.5)		/* smaller makes output img brighter */
#define	IMAX		0xffff		/* max intensity value */
#define EXTRAFUDGE	128		/* some people write BAD .gif files */

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

unsigned short gamtab[256];

void
makegamtab(float gam)
{
    int i;

    for(i=0; i<256; i++) 
	gamtab[i] = (unsigned short) (IMAX*pow(i/255.0,gam)+0.5);
}

char* stuff[] = {
"usage: gif2tiff [options] input.gif output.tif",
"where options are:",
" -r #		make each strip have no more than # rows",
"",
" -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 none	use no compression algorithm on output",
"",
"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);
}

#define COLSIZE 256

unsigned char *stackp;
unsigned int prefix[4096];
unsigned char suffix[4096];
unsigned char stack[4096];
int datasize,codesize,codemask;     /* Decoder working variables */
int clear,eoi;                      /* Special code values */
int avail, oldcode;

FILE *infile;
int global;                        /* Is there a global color map? */
int globalbits;                     /* Number of bits of global colors */
unsigned char globalmap[COLSIZE][3];/* RGB values for global color map */
unsigned char *raster;              /* Decoded image data */
unsigned long width, height;
unsigned short red[COLSIZE];
unsigned short green[COLSIZE];
unsigned short blue[COLSIZE];
char *filename, *imagename;

static	uint16 compression = COMPRESSION_PACKBITS;
static	uint16 predictor = 0;
static	uint32 rowsperstrip = (uint32) -1;
static	int processCompressOptions(char*);

int	convert(void);
int	checksignature(void);
void	readscreen(void);
int	readgifimage(char*);
void	readextension(void);
int	readraster(void);
int	process(int, unsigned char**);
void	initcolors(unsigned char [COLSIZE][3], int);
void	rasterize(int, char*);

int
main(int argc, char* argv[])
{
    extern int optind;
    extern char *optarg;
    int c, status;

    while ((c = getopt(argc, argv, "c:r:")) != -1)
	    switch (c) {
	    case 'c':		/* compression scheme */
		    if (!processCompressOptions(optarg))
			    usage();
		    break;
	    case 'r':		/* rows/strip */
		    rowsperstrip = atoi(optarg);
		    break;
	    case '?':
		    usage();
		    /*NOTREACHED*/
	    }
    if (argc - optind != 2)
	    usage();

    makegamtab(GIFGAMMA);
    filename = argv[optind];
    imagename = argv[optind+1];
    if ((infile = fopen(imagename, "rb")) != NULL) {
	int c;
	fclose(infile);
	printf("overwrite %s? ", imagename); fflush(stdout);
	c = getc(stdin);
	if (c != 'y' && c != 'Y')
	    return (1);
    }
    if ((infile = fopen(filename, "rb")) == NULL) {
	perror(filename);
	return (1);
    }
    status = convert();
    fclose(infile);
    return (status);
}

static int
processCompressOptions(char* opt)
{
	if (streq(opt, "none"))
		compression = COMPRESSION_NONE;
	else if (streq(opt, "packbits"))
		compression = COMPRESSION_PACKBITS;
	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
convert(void)
{
    int ch;
    char* mode = "w";

    if (!checksignature())
        return (-1);
    readscreen();
    while ((ch = getc(infile)) != ';' && ch != EOF) {
        switch (ch) {
            case '\0':  break;  /* this kludge for non-standard files */
            case ',':   if (!readgifimage(mode))
                           return (-1);
			mode = "a";		/* subsequent images append */
                        break;
            case '!':   readextension();
                        break;
            default:    fprintf(stderr, "illegal GIF block type\n");
                        return (-1);
        }
    }
    return (0);
}

int
checksignature(void)
{
    char buf[6];

    fread(buf,1,6,infile);
    if (strncmp(buf,"GIF",3)) {
        fprintf(stderr, "file is not a GIF file\n");
        return 0;
    }
    if (strncmp(&buf[3],"87a",3)) {
        fprintf(stderr, "unknown GIF version number\n");
        return 0;
    }
    return 1;
}

/*
 * 	readscreen - 
 *		Get information which is global to all the images stored 
 *	in the file
 */
void
readscreen(void)
{
    unsigned char buf[7];

    fread(buf,1,7,infile);
    global = buf[4] & 0x80;
    if (global) {
        globalbits = (buf[4] & 0x07) + 1;
        fread(globalmap,3,1<<globalbits,infile);
    }
}

int
readgifimage(char* mode)
{
    unsigned char buf[9];
    int local, interleaved;
    unsigned char localmap[256][3];
    int localbits;
    int status;

    if (fread(buf, 1, 9, infile) == 0) {
        perror(filename);
	return (0);
    }
    width = buf[4] + (buf[5] << 8);
    height = buf[6] + (buf[7] << 8);
    local = buf[8] & 0x80;
    interleaved = buf[8] & 0x40;

    if (local == 0 && global == 0) {
        fprintf(stderr, "no colormap present for image\n");
        return (0);
    }
    if ((raster = (unsigned char*) _TIFFmalloc(width*height+EXTRAFUDGE)) == NULL) {
        fprintf(stderr, "not enough memory for image\n");
        return (0);
    }
    if (local) {
        localbits = (buf[8] & 0x7) + 1;

        fprintf(stderr, "   local colors: %d\n", 1<<localbits);

        fread(localmap, 3, 1<<localbits, infile);
        initcolors(localmap, 1<<localbits);
    } else if (global) {
        initcolors(globalmap, 1<<globalbits);
    }
    if ((status = readraster()))
	rasterize(interleaved, mode);
    _TIFFfree(raster);
    return status;
}

/*
 * 	readextension -
 *		Read a GIF extension block (and do nothing with it).
 *
 */
void
readextension(void)
{
    int count;
    char buf[255];

    (void) getc(infile);
    while ((count = getc(infile)))
        fread(buf, 1, count, infile);
}

/*
 * 	readraster -
 *		Decode a raster image
 *
 */
int
readraster(void)
{
    unsigned char *fill = raster;
    unsigned char buf[255];
    register int bits=0;
    register unsigned long datum=0;
    register unsigned char *ch;
    register int count, code;
    int status = 1;

    datasize = getc(infile);
    clear = 1 << datasize;
    eoi = clear + 1;
    avail = clear + 2;
    oldcode = -1;
    codesize = datasize + 1;
    codemask = (1 << codesize) - 1;
    for (code = 0; code < clear; code++) {
	prefix[code] = 0;
	suffix[code] = code;
    }
    stackp = stack;
    for (count = getc(infile); count > 0; count = getc(infile)) {
	fread(buf,1,count,infile);
	for (ch=buf; count-- > 0; ch++) {
	    datum += (unsigned long) *ch << bits;
	    bits += 8;
	    while (bits >= codesize) {
		code = datum & codemask;
		datum >>= codesize;
		bits -= codesize;
		if (code == eoi) {               /* This kludge put in */
		    goto exitloop;               /* because some GIF files*/
		}                                /* aren't standard */
		if (!process(code, &fill)) {
		    status = 0;
		    goto exitloop;
		}
	    }
	}
	if (fill >= raster + width*height) {
	    fprintf(stderr, "raster full before eoi code\n");
	    break;
	}
    }
exitloop:
    if (fill != raster + width*height)  {
	fprintf(stderr, "warning: wrong rastersize: %ld bytes\n",
						      (long) (fill-raster));
	fprintf(stderr, "         instead of %ld bytes\n",
						      (long) width*height);
    }
    return status;
}

/*
 * 	process - 
 *		Process a compression code.  "clear" resets the code table.  
 *	Otherwise make a new code table entry, and output the bytes 
 *	associated with the code.
 */
int
process(register int code, unsigned char** fill)
{
    int incode;
    static unsigned char firstchar;

    if (code == clear) {
	codesize = datasize + 1;
	codemask = (1 << codesize) - 1;
	avail = clear + 2;
	oldcode = -1;
	return 1;
    }

    if (oldcode == -1) {
	*(*fill)++ = suffix[code];
	firstchar = oldcode = code;
	return 1;
    }
    if (code > avail) {
	fprintf(stderr, "code %d too large for %d\n", code, avail);
	return 0; 
    }

    incode = code;
    if (code == avail) {      /* the first code is always < avail */
	*stackp++ = firstchar;
	code = oldcode;
    }
    while (code > clear) {
	*stackp++ = suffix[code];
	code = prefix[code];
    }

    *stackp++ = firstchar = suffix[code];
    prefix[avail] = oldcode;
    suffix[avail] = firstchar;
    avail++;

    if (((avail & codemask) == 0) && (avail < 4096)) {
	codesize++;
	codemask += avail;
    }
    oldcode = incode;
    do {
	*(*fill)++ = *--stackp;
    } while (stackp > stack);
    return 1;
}

/*
 * 	initcolors -
 *		Convert a color map (local or global) to arrays with R, G and B
 * 	values. 
 *
 */
void
initcolors(unsigned char colormap[COLSIZE][3], int ncolors)
{
    register int i;

    for (i = 0; i < ncolors; i++) {
        red[i]   = gamtab[colormap[i][0]];
        green[i] = gamtab[colormap[i][1]];
        blue[i]  = gamtab[colormap[i][2]];
    }
}

void
rasterize(int interleaved, char* mode)
{
    register unsigned long row;
    unsigned char *newras;
    unsigned char *ras;
    TIFF *tif;
    tstrip_t strip;
    tsize_t stripsize;

    if ((newras = (unsigned char*) _TIFFmalloc(width*height+EXTRAFUDGE)) == NULL) {
        fprintf(stderr, "not enough memory for image\n");
        return;
    }
#define DRAWSEGMENT(offset, step) {			\
        for (row = offset; row < height; row += step) {	\
            _TIFFmemcpy(newras + row*width, ras, width);\
            ras += width;                            	\
        }						\
    }
    ras = raster;
    if (interleaved) {
        DRAWSEGMENT(0, 8);
        DRAWSEGMENT(4, 8);
        DRAWSEGMENT(2, 4);
        DRAWSEGMENT(1, 2);
    } else 
        DRAWSEGMENT(0, 1);
#undef DRAWSEGMENT

    tif = TIFFOpen(imagename, mode);
    if (!tif) {
	TIFFError(imagename,"Can not open output image");
	exit(-1);
    }
    TIFFSetField(tif, TIFFTAG_IMAGEWIDTH, (uint32) width);
    TIFFSetField(tif, TIFFTAG_IMAGELENGTH, (uint32) height);
    TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_PALETTE);
    TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
    TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1);
    TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 8);
    TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP, 
	rowsperstrip = TIFFDefaultStripSize(tif, rowsperstrip));
    TIFFSetField(tif, TIFFTAG_COMPRESSION, compression);
    switch (compression) {
    case COMPRESSION_LZW:
    case COMPRESSION_DEFLATE:
	    if (predictor != 0)
		    TIFFSetField(tif, TIFFTAG_PREDICTOR, predictor);
	    break;
    }
    TIFFSetField(tif, TIFFTAG_COLORMAP, red, green, blue);
    TIFFSetField(tif, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
    strip = 0;
    stripsize = TIFFStripSize(tif);
    for (row=0; row<height; row += rowsperstrip) {
	if (TIFFWriteEncodedStrip(tif, strip, newras+row*width, stripsize) < 0)
	    break;
	strip++;
    }
    TIFFClose(tif);

    _TIFFfree(newras);
}

/* vim: set ts=8 sts=8 sw=8 noet: */
Commit	Line	Data
8414a40c VZ	1	/* $Id$ */
	2
	3	/*
	4	* Copyright (c) 1990-1997 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	/*
	28	* convert a GIF file into a TIFF file.
	29	* based on Paul Haeberli's fromgif program which in turn is
	30	* based on a GIF file reader by Marcel J.E. Mol March 23 1989
	31	*
	32	* if input is 320 by 200 pixel aspect is probably 1.2
	33	* if input is 640 350 pixel aspect is probably 1.37
	34	*
	35	*/
	36	#include "tif_config.h"
	37
	38	#include <stdio.h>
	39	#include <stdlib.h>
	40	#include <string.h>
	41	#include <math.h>
	42
	43	#ifdef HAVE_UNISTD_H
	44	# include <unistd.h>
	45	#endif
	46
	47	#include "tiffio.h"
	48
	49	#define GIFGAMMA (1.5) /* smaller makes output img brighter */
	50	#define IMAX 0xffff /* max intensity value */
	51	#define EXTRAFUDGE 128 /* some people write BAD .gif files */
	52
	53	#define streq(a,b) (strcmp(a,b) == 0)
	54	#define strneq(a,b,n) (strncmp(a,b,n) == 0)
	55
	56	unsigned short gamtab[256];
	57
	58	void
	59	makegamtab(float gam)
	60	{
	61	int i;
	62
	63	for(i=0; i<256; i++)
	64	gamtab[i] = (unsigned short) (IMAX*pow(i/255.0,gam)+0.5);
65	}
66
67	char* stuff[] = {
68	"usage: gif2tiff [options] input.gif output.tif",
69	"where options are:",
70	" -r # make each strip have no more than # rows",
71	"",
72	" -c lzw[:opts] compress output with Lempel-Ziv & Welch encoding",
73	" -c zip[:opts] compress output with deflate encoding",
74	" -c packbits compress output with packbits encoding",
75	" -c none use no compression algorithm on output",
76	"",
77	"LZW and deflate options:",
78	" # set predictor value",
79	"For example, -c lzw:2 to get LZW-encoded data with horizontal differencing",
80	NULL
81	};
82
83	static void
84	usage(void)
85	{
86	char buf[BUFSIZ];
87	int i;
88
89	setbuf(stderr, buf);
90	fprintf(stderr, "%s\n\n", TIFFGetVersion());
91	for (i = 0; stuff[i] != NULL; i++)
92	fprintf(stderr, "%s\n", stuff[i]);
93	exit(-1);
94	}
95
96	#define COLSIZE 256
97
98	unsigned char *stackp;
99	unsigned int prefix[4096];
100	unsigned char suffix[4096];
101	unsigned char stack[4096];
102	int datasize,codesize,codemask; /* Decoder working variables */
103	int clear,eoi; /* Special code values */
104	int avail, oldcode;
105
106	FILE *infile;
107	int global; /* Is there a global color map? */
108	int globalbits; /* Number of bits of global colors */
109	unsigned char globalmap[COLSIZE][3];/* RGB values for global color map */
110	unsigned char raster; / Decoded image data */
111	unsigned long width, height;
112	unsigned short red[COLSIZE];
113	unsigned short green[COLSIZE];
114	unsigned short blue[COLSIZE];
115	char filename, imagename;
116
117	static uint16 compression = COMPRESSION_PACKBITS;
118	static uint16 predictor = 0;
119	static uint32 rowsperstrip = (uint32) -1;
120	static int processCompressOptions(char*);
121
122	int convert(void);
123	int checksignature(void);
124	void readscreen(void);
125	int readgifimage(char*);
126	void readextension(void);
127	int readraster(void);
128	int process(int, unsigned char**);
129	void initcolors(unsigned char [COLSIZE][3], int);
130	void rasterize(int, char*);
131
132	int
133	main(int argc, char* argv[])
134	{
135	extern int optind;
136	extern char *optarg;
137	int c, status;
138
139	while ((c = getopt(argc, argv, "c:r:")) != -1)
140	switch (c) {
141	case 'c': /* compression scheme */
142	if (!processCompressOptions(optarg))
143	usage();
144	break;
145	case 'r': /* rows/strip */
146	rowsperstrip = atoi(optarg);
147	break;
148	case '?':
149	usage();
150	/NOTREACHED/
151	}
152	if (argc - optind != 2)
153	usage();
154
155	makegamtab(GIFGAMMA);
156	filename = argv[optind];
157	imagename = argv[optind+1];
158	if ((infile = fopen(imagename, "rb")) != NULL) {
159	int c;
160	fclose(infile);
161	printf("overwrite %s? ", imagename); fflush(stdout);
162	c = getc(stdin);
163	if (c != 'y' && c != 'Y')
164	return (1);
165	}
166	if ((infile = fopen(filename, "rb")) == NULL) {
167	perror(filename);
168	return (1);
169	}
170	status = convert();
171	fclose(infile);
172	return (status);
173	}
174
175	static int
176	processCompressOptions(char* opt)
177	{
178	if (streq(opt, "none"))
179	compression = COMPRESSION_NONE;
180	else if (streq(opt, "packbits"))
181	compression = COMPRESSION_PACKBITS;
182	else if (strneq(opt, "lzw", 3)) {
183	char* cp = strchr(opt, ':');
184	if (cp)
185	predictor = atoi(cp+1);
186	compression = COMPRESSION_LZW;
187	} else if (strneq(opt, "zip", 3)) {
188	char* cp = strchr(opt, ':');
189	if (cp)
190	predictor = atoi(cp+1);
191	compression = COMPRESSION_DEFLATE;
192	} else
193	return (0);
194	return (1);
195	}
196
197	int
198	convert(void)
199	{
200	int ch;
201	char* mode = "w";
202
203	if (!checksignature())
204	return (-1);
205	readscreen();
206	while ((ch = getc(infile)) != ';' && ch != EOF) {
207	switch (ch) {
208	case '\0': break; /* this kludge for non-standard files */
209	case ',': if (!readgifimage(mode))
210	return (-1);
211	mode = "a"; /* subsequent images append */
212	break;
213	case '!': readextension();
214	break;
215	default: fprintf(stderr, "illegal GIF block type\n");
216	return (-1);
217	}
218	}
219	return (0);
220	}
221
222	int
223	checksignature(void)
224	{
225	char buf[6];
226
227	fread(buf,1,6,infile);
228	if (strncmp(buf,"GIF",3)) {
229	fprintf(stderr, "file is not a GIF file\n");
230	return 0;
231	}
232	if (strncmp(&buf[3],"87a",3)) {
233	fprintf(stderr, "unknown GIF version number\n");
234	return 0;
235	}
236	return 1;
237	}
238
239	/*
240	* readscreen -
241	* Get information which is global to all the images stored
242	* in the file
243	*/
244	void
245	readscreen(void)
246	{
247	unsigned char buf[7];
248
249	fread(buf,1,7,infile);
250	global = buf[4] & 0x80;
251	if (global) {
252	globalbits = (buf[4] & 0x07) + 1;
253	fread(globalmap,3,1<<globalbits,infile);
254	}
255	}
256
257	int
258	readgifimage(char* mode)
259	{
260	unsigned char buf[9];
261	int local, interleaved;
262	unsigned char localmap[256][3];
263	int localbits;
264	int status;
265
266	if (fread(buf, 1, 9, infile) == 0) {
267	perror(filename);
268	return (0);
269	}
270	width = buf[4] + (buf[5] << 8);
271	height = buf[6] + (buf[7] << 8);
272	local = buf[8] & 0x80;
273	interleaved = buf[8] & 0x40;
274
275	if (local == 0 && global == 0) {
276	fprintf(stderr, "no colormap present for image\n");
277	return (0);
278	}
279	if ((raster = (unsigned char) _TIFFmalloc(widthheight+EXTRAFUDGE)) == NULL) {
280	fprintf(stderr, "not enough memory for image\n");
281	return (0);
282	}
283	if (local) {
284	localbits = (buf[8] & 0x7) + 1;
285
286	fprintf(stderr, " local colors: %d\n", 1<<localbits);
287
288	fread(localmap, 3, 1<<localbits, infile);
289	initcolors(localmap, 1<<localbits);
290	} else if (global) {
291	initcolors(globalmap, 1<<globalbits);
292	}
293	if ((status = readraster()))
294	rasterize(interleaved, mode);
295	_TIFFfree(raster);
296	return status;
297	}
298
299	/*
300	* readextension -
301	* Read a GIF extension block (and do nothing with it).
302	*
303	*/
304	void
305	readextension(void)
306	{
307	int count;
308	char buf[255];
309
310	(void) getc(infile);
311	while ((count = getc(infile)))
312	fread(buf, 1, count, infile);
313	}
314
315	/*
316	* readraster -
317	* Decode a raster image
318	*
319	*/
320	int
321	readraster(void)
322	{
323	unsigned char *fill = raster;
324	unsigned char buf[255];
325	register int bits=0;
326	register unsigned long datum=0;
327	register unsigned char *ch;
328	register int count, code;
329	int status = 1;
330
331	datasize = getc(infile);
332	clear = 1 << datasize;
333	eoi = clear + 1;
334	avail = clear + 2;
335	oldcode = -1;
336	codesize = datasize + 1;
337	codemask = (1 << codesize) - 1;
338	for (code = 0; code < clear; code++) {
339	prefix[code] = 0;
340	suffix[code] = code;
341	}
342	stackp = stack;
343	for (count = getc(infile); count > 0; count = getc(infile)) {
344	fread(buf,1,count,infile);
345	for (ch=buf; count-- > 0; ch++) {
346	datum += (unsigned long) *ch << bits;
347	bits += 8;
348	while (bits >= codesize) {
349	code = datum & codemask;
350	datum >>= codesize;
351	bits -= codesize;
352	if (code == eoi) { /* This kludge put in */
353	goto exitloop; /* because some GIF files*/
354	} /* aren't standard */
355	if (!process(code, &fill)) {
356	status = 0;
357	goto exitloop;
358	}
359	}
360	}
361	if (fill >= raster + width*height) {
362	fprintf(stderr, "raster full before eoi code\n");
363	break;
364	}
365	}
366	exitloop:
367	if (fill != raster + width*height) {
368	fprintf(stderr, "warning: wrong rastersize: %ld bytes\n",
369	(long) (fill-raster));
370	fprintf(stderr, " instead of %ld bytes\n",
371	(long) width*height);
372	}
373	return status;
374	}
375
376	/*
377	* process -
378	* Process a compression code. "clear" resets the code table.
379	* Otherwise make a new code table entry, and output the bytes
380	* associated with the code.
381	*/
382	int
383	process(register int code, unsigned char** fill)
384	{
385	int incode;
386	static unsigned char firstchar;
387
388	if (code == clear) {
389	codesize = datasize + 1;
390	codemask = (1 << codesize) - 1;
391	avail = clear + 2;
392	oldcode = -1;
393	return 1;
394	}
395
396	if (oldcode == -1) {
397	(fill)++ = suffix[code];
398	firstchar = oldcode = code;
399	return 1;
400	}
401	if (code > avail) {
402	fprintf(stderr, "code %d too large for %d\n", code, avail);
403	return 0;
404	}
405
406	incode = code;
407	if (code == avail) { /* the first code is always < avail */
408	*stackp++ = firstchar;
409	code = oldcode;
410	}
411	while (code > clear) {
412	*stackp++ = suffix[code];
413	code = prefix[code];
414	}
415
416	*stackp++ = firstchar = suffix[code];
417	prefix[avail] = oldcode;
418	suffix[avail] = firstchar;
419	avail++;
420
421	if (((avail & codemask) == 0) && (avail < 4096)) {
422	codesize++;
423	codemask += avail;
424	}
425	oldcode = incode;
426	do {
427	(fill)++ = *--stackp;
428	} while (stackp > stack);
429	return 1;
430	}
431
432	/*
433	* initcolors -
434	* Convert a color map (local or global) to arrays with R, G and B
435	* values.
436	*
437	*/
438	void
439	initcolors(unsigned char colormap[COLSIZE][3], int ncolors)
440	{
441	register int i;
442
443	for (i = 0; i < ncolors; i++) {
444	red[i] = gamtab[colormap[i][0]];
445	green[i] = gamtab[colormap[i][1]];
446	blue[i] = gamtab[colormap[i][2]];
447	}
448	}
449
450	void
451	rasterize(int interleaved, char* mode)
452	{
453	register unsigned long row;
454	unsigned char *newras;
455	unsigned char *ras;
456	TIFF *tif;
457	tstrip_t strip;
458	tsize_t stripsize;
459
460	if ((newras = (unsigned char) _TIFFmalloc(widthheight+EXTRAFUDGE)) == NULL) {
461	fprintf(stderr, "not enough memory for image\n");
462	return;
463	}
464	#define DRAWSEGMENT(offset, step) { \
465	for (row = offset; row < height; row += step) { \
466	_TIFFmemcpy(newras + row*width, ras, width);\
467	ras += width; \
468	} \
469	}
470	ras = raster;
471	if (interleaved) {
472	DRAWSEGMENT(0, 8);
473	DRAWSEGMENT(4, 8);
474	DRAWSEGMENT(2, 4);
475	DRAWSEGMENT(1, 2);
476	} else
477	DRAWSEGMENT(0, 1);
478	#undef DRAWSEGMENT
479
480	tif = TIFFOpen(imagename, mode);
481	if (!tif) {
482	TIFFError(imagename,"Can not open output image");
483	exit(-1);
484	}
485	TIFFSetField(tif, TIFFTAG_IMAGEWIDTH, (uint32) width);
486	TIFFSetField(tif, TIFFTAG_IMAGELENGTH, (uint32) height);
487	TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_PALETTE);
488	TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
489	TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1);
490	TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 8);
491	TIFFSetField(tif, TIFFTAG_ROWSPERSTRIP,
492	rowsperstrip = TIFFDefaultStripSize(tif, rowsperstrip));
493	TIFFSetField(tif, TIFFTAG_COMPRESSION, compression);
494	switch (compression) {
495	case COMPRESSION_LZW:
496	case COMPRESSION_DEFLATE:
497	if (predictor != 0)
498	TIFFSetField(tif, TIFFTAG_PREDICTOR, predictor);
499	break;
500	}
501	TIFFSetField(tif, TIFFTAG_COLORMAP, red, green, blue);
502	TIFFSetField(tif, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
503	strip = 0;
504	stripsize = TIFFStripSize(tif);
505	for (row=0; row<height; row += rowsperstrip) {
506	if (TIFFWriteEncodedStrip(tif, strip, newras+row*width, stripsize) < 0)
507	break;
508	strip++;
509	}
510	TIFFClose(tif);
511
512	_TIFFfree(newras);
513	}
514
515	/* vim: set ts=8 sts=8 sw=8 noet: */