/* returns 0 on success, 1 on failure */
static int _gdImageGifCtx(gdImagePtr im, gdIOCtxPtr out)
{
gdImagePtr pim = 0, tim = im;
int interlace, BitsPerPixel;
interlace = im->interlace;
if (im->trueColor) {
/* Expensive, but the only way that produces an
acceptable result: mix down to a palette
based temporary image. */
pim = gdImageCreatePaletteFromTrueColor(im, 1, 256);
if (!pim) {
return 1;
}
tim = pim;
}
BitsPerPixel = colorstobpp(tim->colorsTotal);
/* All set, let's do it. */
GIFEncode(
out, tim->sx, tim->sy, interlace, 0, tim->transparent, BitsPerPixel,
tim->red, tim->green, tim->blue, tim);
if (pim) {
/* Destroy palette based temporary image. */
gdImageDestroy( pim);
}
return 0;
}
int
main(int argc, char *argv[])
{
int bitsperpix;
int i;
SET_DEFAULT_BINARY();
SET_FILE_BINARY(stdin);
SET_FILE_BINARY(stdout);
progname = argv[0];
samplefac = 0;
for (i = 1; i < argc; i++)
if (argv[i][0] == '-')
switch (argv[i][1]) {
case 'g':
gamv = atof(argv[++i]);
break;
case 'b':
greyscale = 1;
break;
case 'd':
dither = !dither;
break;
case 'c':
ncolors = atoi(argv[++i]);
break;
case 'e':
if (argv[i+1][0] != '+' && argv[i+1][0] != '-')
goto userr;
bradj = atoi(argv[++i]);
break;
case 'n':
samplefac = atoi(argv[++i]);
break;
default:
goto userr;
}
else
break;
if (i < argc-2)
goto userr;
if (i <= argc-1 && freopen(argv[i], "r", stdin) == NULL) {
fprintf(stderr, "%s: cannot open input \"%s\"\n",
progname, argv[i]);
exit(1);
}
if (i == argc-2 && freopen(argv[i+1], "w", stdout) == NULL) {
fprintf(stderr, "%s: cannot open output \"%s\"\n",
progname, argv[i+1]);
exit(1);
}
if (checkheader(stdin, COLRFMT, NULL) < 0 ||
fgetresolu(&xmax, &ymax, stdin) < 0) {
fprintf(stderr, "%s: bad picture format\n", progname);
exit(1);
}
picstart = ftell(stdin);
currow = -1;
scanln = (COLR *)malloc(xmax*sizeof(COLR));
if (scanln == NULL) {
fprintf(stderr, "%s: out of memory\n", progname);
exit(1);
}
/* set up gamma correction */
setcolrgam(gamv);
/* figure out the bits per pixel */
if ((ncolors < 2) | (ncolors > MAXCOLORS))
ncolors = MAXCOLORS;
for (bitsperpix = 1; ncolors > 1<<bitsperpix; bitsperpix++)
;
/* compute color map */
if (greyscale)
mkgrymap(ncolors);
else
mkclrmap(ncolors);
/* convert image */
GIFEncode(stdout, xmax, ymax, 0, 0, bitsperpix,
rmap, gmap, bmap, getgifpix);
exit(0);
userr:
fprintf(stderr,
"Usage: %s [-b][-d][-n samp][-c ncolors][-g gamv][-e +/-stops] input [output]\n",
progname);
exit(1);
}
