1 |
– |
/* Copyright (c) 1992 Regents of the University of California */ |
2 |
– |
|
1 |
|
#ifndef lint |
2 |
< |
static char SCCSid[] = "$SunId$ LBL"; |
2 |
> |
static const char RCSid[] = "$Id$"; |
3 |
|
#endif |
6 |
– |
|
4 |
|
/* |
5 |
|
* Simple median-cut color quantization based on colortab.c |
6 |
|
*/ |
20 |
|
#define part(cn) ((cn)>>2) |
21 |
|
#define prim(cn) ((cn)&3) |
22 |
|
/* our color table (global) */ |
23 |
< |
BYTE clrtab[256][3]; |
23 |
> |
extern BYTE clrtab[256][3]; |
24 |
|
/* histogram of colors / color assignments */ |
25 |
|
static unsigned histo[NRED][NGRN][NBLU]; |
26 |
|
#define cndx(c) histo[((c)[RED]*NRED)>>8][((c)[GRN]*NGRN)>>8][((c)[BLU]*NBLU)>>8] |
28 |
|
static int CLRCUBE[3][2] = {0,NRED,0,NGRN,0,NBLU}; |
29 |
|
/* maximum propagated error during dithering */ |
30 |
|
#define MAXERR 20 |
31 |
+ |
/* define CLOSEST to get closest colors */ |
32 |
+ |
#ifndef CLOSEST |
33 |
+ |
#ifdef SPEED |
34 |
+ |
#if SPEED > 8 |
35 |
+ |
#define CLOSEST 1 /* this step takes a little longer */ |
36 |
+ |
#endif |
37 |
+ |
#endif |
38 |
+ |
#endif |
39 |
|
|
40 |
+ |
static cut(), mktabent(), closest(), addneigh(), setclosest(); |
41 |
+ |
static int split(); |
42 |
+ |
static unsigned dist(); |
43 |
|
|
44 |
< |
new_histo() /* clear our histogram */ |
44 |
> |
|
45 |
> |
new_histo(n) /* clear our histogram */ |
46 |
> |
int n; |
47 |
|
{ |
48 |
|
bzero((char *)histo, sizeof(histo)); |
49 |
+ |
return(0); |
50 |
|
} |
51 |
|
|
52 |
|
|
77 |
|
ncolors = 256; |
78 |
|
/* partition color space */ |
79 |
|
cut(CLRCUBE, 0, ncolors); |
80 |
+ |
#ifdef CLOSEST |
81 |
+ |
closest(ncolors); /* ensure colors picked are closest */ |
82 |
+ |
#endif |
83 |
+ |
/* reset dithering function */ |
84 |
+ |
dith_colrs((BYTE *)NULL, (COLR *)NULL, 0); |
85 |
|
/* return new color table size */ |
86 |
|
return(ncolors); |
87 |
|
} |
112 |
|
register COLR *cs; |
113 |
|
int n; |
114 |
|
{ |
115 |
< |
static short (*cerr)[3]; |
115 |
> |
static short (*cerr)[3] = NULL; |
116 |
|
static int N = 0; |
117 |
|
int err[3], errp[3]; |
118 |
|
register int x, i; |
119 |
|
|
120 |
|
if (n != N) { /* get error propogation array */ |
121 |
< |
if (N) |
122 |
< |
cerr = (short (*)[3])realloc((char *)cerr, |
123 |
< |
3*n*sizeof(short)); |
124 |
< |
else |
121 |
> |
if (N) { |
122 |
> |
free((void *)cerr); |
123 |
> |
cerr = NULL; |
124 |
> |
} |
125 |
> |
if (n) |
126 |
|
cerr = (short (*)[3])malloc(3*n*sizeof(short)); |
127 |
|
if (cerr == NULL) { |
128 |
|
N = 0; |
187 |
|
#define c0 r |
188 |
|
register int r, g, b; |
189 |
|
int pri; |
190 |
< |
int t[HMAX], med; |
190 |
> |
long t[HMAX], med; |
191 |
|
/* find dominant axis */ |
192 |
|
pri = RED; |
193 |
|
if (box[GRN][1]-box[GRN][0] > box[pri][1]-box[pri][0]) |
243 |
|
int p; |
244 |
|
register int box[3][2]; |
245 |
|
{ |
246 |
< |
long sum[3]; |
247 |
< |
int r, g, n; |
248 |
< |
register int b, c; |
246 |
> |
unsigned long sum[3]; |
247 |
> |
unsigned r, g; |
248 |
> |
unsigned long n; |
249 |
> |
register unsigned b, c; |
250 |
|
/* sum pixels in box */ |
251 |
|
n = 0; |
252 |
|
sum[RED] = sum[GRN] = sum[BLU] = 0; |
261 |
|
} |
262 |
|
histo[r][g][b] = p; /* assign pixel */ |
263 |
|
} |
264 |
+ |
if (n >= (1L<<23)/HMAX) { /* avoid overflow */ |
265 |
+ |
sum[RED] /= n; |
266 |
+ |
sum[GRN] /= n; |
267 |
+ |
sum[BLU] /= n; |
268 |
+ |
n = 1; |
269 |
+ |
} |
270 |
|
if (n) { /* compute average */ |
271 |
|
clrtab[p][RED] = sum[RED]*256/NRED/n; |
272 |
|
clrtab[p][GRN] = sum[GRN]*256/NGRN/n; |
277 |
|
clrtab[p][BLU] = (box[BLU][0]+box[BLU][1])*256/NBLU/2; |
278 |
|
} |
279 |
|
} |
280 |
+ |
|
281 |
+ |
|
282 |
+ |
#ifdef CLOSEST |
283 |
+ |
#define NBSIZ 32 |
284 |
+ |
static |
285 |
+ |
closest(n) /* make sure we have the closest colors */ |
286 |
+ |
int n; |
287 |
+ |
{ |
288 |
+ |
BYTE *neigh[256]; |
289 |
+ |
register int r, g, b; |
290 |
+ |
#define i r |
291 |
+ |
/* get space for neighbor lists */ |
292 |
+ |
for (i = 0; i < n; i++) { |
293 |
+ |
if ((neigh[i] = (BYTE *)malloc(NBSIZ)) == NULL) { |
294 |
+ |
while (i--) |
295 |
+ |
free(neigh[i]); |
296 |
+ |
return; /* ENOMEM -- abandon effort */ |
297 |
+ |
} |
298 |
+ |
neigh[i][0] = i; /* identity is terminator */ |
299 |
+ |
} |
300 |
+ |
/* make neighbor lists */ |
301 |
+ |
for (r = 0; r < NRED; r++) |
302 |
+ |
for (g = 0; g < NGRN; g++) |
303 |
+ |
for (b = 0; b < NBLU; b++) { |
304 |
+ |
if (r < NRED-1 && histo[r][g][b] != histo[r+1][g][b]) |
305 |
+ |
addneigh(neigh, histo[r][g][b], histo[r+1][g][b]); |
306 |
+ |
if (g < NGRN-1 && histo[r][g][b] != histo[r][g+1][b]) |
307 |
+ |
addneigh(neigh, histo[r][g][b], histo[r][g+1][b]); |
308 |
+ |
if (b < NBLU-1 && histo[r][g][b] != histo[r][g][b+1]) |
309 |
+ |
addneigh(neigh, histo[r][g][b], histo[r][g][b+1]); |
310 |
+ |
} |
311 |
+ |
/* assign closest values */ |
312 |
+ |
for (r = 0; r < NRED; r++) |
313 |
+ |
for (g = 0; g < NGRN; g++) |
314 |
+ |
for (b = 0; b < NBLU; b++) |
315 |
+ |
setclosest(neigh, r, g, b); |
316 |
+ |
/* free neighbor lists */ |
317 |
+ |
for (i = 0; i < n; i++) |
318 |
+ |
free(neigh[i]); |
319 |
+ |
#undef i |
320 |
+ |
} |
321 |
+ |
|
322 |
+ |
|
323 |
+ |
static |
324 |
+ |
addneigh(nl, i, j) /* i and j are neighbors; add them to list */ |
325 |
+ |
register BYTE *nl[]; |
326 |
+ |
register int i; |
327 |
+ |
int j; |
328 |
+ |
{ |
329 |
+ |
int nc; |
330 |
+ |
char *nnl; |
331 |
+ |
register int t; |
332 |
+ |
|
333 |
+ |
for (nc = 0; nc < 2; nc++) { /* do both neighbors */ |
334 |
+ |
for (t = 0; nl[i][t] != i; t++) |
335 |
+ |
if (nl[i][t] == j) |
336 |
+ |
break; /* in list already */ |
337 |
+ |
if (nl[i][t] == i) { /* add to list */ |
338 |
+ |
nl[i][t++] = j; |
339 |
+ |
if (t % NBSIZ == 0) { /* enlarge list */ |
340 |
+ |
if ((nnl = realloc(nl[i], t+NBSIZ)) == NULL) |
341 |
+ |
t--; |
342 |
+ |
else |
343 |
+ |
nl[i] = (BYTE *)nnl; |
344 |
+ |
} |
345 |
+ |
nl[i][t] = i; /* terminator */ |
346 |
+ |
} |
347 |
+ |
t = i; i = j; j = t; /* swap and do it again */ |
348 |
+ |
} |
349 |
+ |
} |
350 |
+ |
|
351 |
+ |
|
352 |
+ |
static unsigned |
353 |
+ |
dist(col, r, g, b) /* find distance from clrtab entry to r,g,b */ |
354 |
+ |
register BYTE col[3]; |
355 |
+ |
int r, g, b; |
356 |
+ |
{ |
357 |
+ |
register int tmp; |
358 |
+ |
register unsigned sum; |
359 |
+ |
|
360 |
+ |
tmp = col[RED]*NRED/256 - r; |
361 |
+ |
sum = tmp*tmp; |
362 |
+ |
tmp = col[GRN]*NGRN/256 - g; |
363 |
+ |
sum += tmp*tmp; |
364 |
+ |
tmp = col[BLU]*NBLU/256 - b; |
365 |
+ |
sum += tmp*tmp; |
366 |
+ |
return(sum); |
367 |
+ |
} |
368 |
+ |
|
369 |
+ |
|
370 |
+ |
static |
371 |
+ |
setclosest(nl, r, g, b) /* find index closest to color and assign */ |
372 |
+ |
BYTE *nl[]; |
373 |
+ |
int r, g, b; |
374 |
+ |
{ |
375 |
+ |
int ident; |
376 |
+ |
unsigned min; |
377 |
+ |
register unsigned d; |
378 |
+ |
register BYTE *p; |
379 |
+ |
/* get starting value */ |
380 |
+ |
min = dist(clrtab[ident=histo[r][g][b]], r, g, b); |
381 |
+ |
/* find minimum */ |
382 |
+ |
for (p = nl[ident]; *p != ident; p++) |
383 |
+ |
if ((d = dist(clrtab[*p], r, g, b)) < min) { |
384 |
+ |
min = d; |
385 |
+ |
histo[r][g][b] = *p; |
386 |
+ |
} |
387 |
+ |
} |
388 |
+ |
#endif |