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 |
|
*/ |
7 |
|
|
8 |
< |
#include "standard.h" |
8 |
> |
#include "copyright.h" |
9 |
|
|
10 |
+ |
#include <string.h> |
11 |
+ |
|
12 |
+ |
#include "standard.h" |
13 |
|
#include "color.h" |
14 |
+ |
|
15 |
|
/* histogram resolution */ |
16 |
|
#define NRED 36 |
17 |
|
#define NGRN 48 |
24 |
|
#define part(cn) ((cn)>>2) |
25 |
|
#define prim(cn) ((cn)&3) |
26 |
|
/* our color table (global) */ |
27 |
< |
BYTE clrtab[256][3]; |
27 |
> |
extern BYTE clrtab[256][3]; |
28 |
|
/* histogram of colors / color assignments */ |
29 |
|
static unsigned histo[NRED][NGRN][NBLU]; |
30 |
|
#define cndx(c) histo[((c)[RED]*NRED)>>8][((c)[GRN]*NGRN)>>8][((c)[BLU]*NBLU)>>8] |
32 |
|
static int CLRCUBE[3][2] = {0,NRED,0,NGRN,0,NBLU}; |
33 |
|
/* maximum propagated error during dithering */ |
34 |
|
#define MAXERR 20 |
35 |
+ |
/* define CLOSEST to get closest colors */ |
36 |
+ |
#ifndef CLOSEST |
37 |
+ |
#ifdef SPEED |
38 |
+ |
#if SPEED > 8 |
39 |
+ |
#define CLOSEST 1 /* this step takes a little longer */ |
40 |
+ |
#endif |
41 |
+ |
#endif |
42 |
+ |
#endif |
43 |
|
|
44 |
+ |
static cut(), mktabent(), closest(), addneigh(), setclosest(); |
45 |
+ |
static int split(); |
46 |
+ |
static unsigned dist(); |
47 |
|
|
48 |
< |
new_histo() /* clear our histogram */ |
48 |
> |
|
49 |
> |
new_histo(n) /* clear our histogram */ |
50 |
> |
int n; |
51 |
|
{ |
52 |
< |
bzero((char *)histo, sizeof(histo)); |
52 |
> |
memset((void *)histo, '\0', sizeof(histo)); |
53 |
> |
return(0); |
54 |
|
} |
55 |
|
|
56 |
|
|
81 |
|
ncolors = 256; |
82 |
|
/* partition color space */ |
83 |
|
cut(CLRCUBE, 0, ncolors); |
84 |
+ |
#ifdef CLOSEST |
85 |
+ |
closest(ncolors); /* ensure colors picked are closest */ |
86 |
+ |
#endif |
87 |
+ |
/* reset dithering function */ |
88 |
+ |
dith_colrs((BYTE *)NULL, (COLR *)NULL, 0); |
89 |
|
/* return new color table size */ |
90 |
|
return(ncolors); |
91 |
|
} |
116 |
|
register COLR *cs; |
117 |
|
int n; |
118 |
|
{ |
119 |
< |
static short (*cerr)[3]; |
119 |
> |
static short (*cerr)[3] = NULL; |
120 |
|
static int N = 0; |
121 |
|
int err[3], errp[3]; |
122 |
|
register int x, i; |
123 |
|
|
124 |
|
if (n != N) { /* get error propogation array */ |
125 |
< |
if (N) |
126 |
< |
cerr = (short (*)[3])realloc((char *)cerr, |
127 |
< |
3*n*sizeof(short)); |
128 |
< |
else |
125 |
> |
if (N) { |
126 |
> |
free((void *)cerr); |
127 |
> |
cerr = NULL; |
128 |
> |
} |
129 |
> |
if (n) |
130 |
|
cerr = (short (*)[3])malloc(3*n*sizeof(short)); |
131 |
|
if (cerr == NULL) { |
132 |
|
N = 0; |
134 |
|
return; |
135 |
|
} |
136 |
|
N = n; |
137 |
< |
bzero((char *)cerr, 3*N*sizeof(short)); |
137 |
> |
memset((void *)cerr, '\0', 3*N*sizeof(short)); |
138 |
|
} |
139 |
|
err[0] = err[1] = err[2] = 0; |
140 |
|
for (x = 0; x < n; x++) { |
173 |
|
} |
174 |
|
/* split box */ |
175 |
|
branch = split(box); |
176 |
< |
bcopy((char *)box, (char *)kb, sizeof(kb)); |
176 |
> |
memcpy((void *)kb, (void *)box, sizeof(kb)); |
177 |
|
/* do left (lesser) branch */ |
178 |
|
kb[prim(branch)][1] = part(branch); |
179 |
|
cut(kb, c0, (c0+c1)>>1); |
191 |
|
#define c0 r |
192 |
|
register int r, g, b; |
193 |
|
int pri; |
194 |
< |
int t[HMAX], med; |
194 |
> |
long t[HMAX], med; |
195 |
|
/* find dominant axis */ |
196 |
|
pri = RED; |
197 |
|
if (box[GRN][1]-box[GRN][0] > box[pri][1]-box[pri][0]) |
247 |
|
int p; |
248 |
|
register int box[3][2]; |
249 |
|
{ |
250 |
< |
long sum[3]; |
251 |
< |
int r, g, n; |
252 |
< |
register int b, c; |
250 |
> |
unsigned long sum[3]; |
251 |
> |
unsigned r, g; |
252 |
> |
unsigned long n; |
253 |
> |
register unsigned b, c; |
254 |
|
/* sum pixels in box */ |
255 |
|
n = 0; |
256 |
|
sum[RED] = sum[GRN] = sum[BLU] = 0; |
257 |
|
for (r = box[RED][0]; r < box[RED][1]; r++) |
258 |
|
for (g = box[GRN][0]; g < box[GRN][1]; g++) |
259 |
|
for (b = box[BLU][0]; b < box[BLU][1]; b++) { |
260 |
< |
if (c = histo[r][g][b]) { |
260 |
> |
if ( (c = histo[r][g][b]) ) { |
261 |
|
n += c; |
262 |
|
sum[RED] += (long)c*r; |
263 |
|
sum[GRN] += (long)c*g; |
265 |
|
} |
266 |
|
histo[r][g][b] = p; /* assign pixel */ |
267 |
|
} |
268 |
+ |
if (n >= (1L<<23)/HMAX) { /* avoid overflow */ |
269 |
+ |
sum[RED] /= n; |
270 |
+ |
sum[GRN] /= n; |
271 |
+ |
sum[BLU] /= n; |
272 |
+ |
n = 1; |
273 |
+ |
} |
274 |
|
if (n) { /* compute average */ |
275 |
|
clrtab[p][RED] = sum[RED]*256/NRED/n; |
276 |
|
clrtab[p][GRN] = sum[GRN]*256/NGRN/n; |
281 |
|
clrtab[p][BLU] = (box[BLU][0]+box[BLU][1])*256/NBLU/2; |
282 |
|
} |
283 |
|
} |
284 |
+ |
|
285 |
+ |
|
286 |
+ |
#ifdef CLOSEST |
287 |
+ |
#define NBSIZ 32 |
288 |
+ |
static |
289 |
+ |
closest(n) /* make sure we have the closest colors */ |
290 |
+ |
int n; |
291 |
+ |
{ |
292 |
+ |
BYTE *neigh[256]; |
293 |
+ |
register int r, g, b; |
294 |
+ |
#define i r |
295 |
+ |
/* get space for neighbor lists */ |
296 |
+ |
for (i = 0; i < n; i++) { |
297 |
+ |
if ((neigh[i] = (BYTE *)malloc(NBSIZ)) == NULL) { |
298 |
+ |
while (i--) |
299 |
+ |
free(neigh[i]); |
300 |
+ |
return; /* ENOMEM -- abandon effort */ |
301 |
+ |
} |
302 |
+ |
neigh[i][0] = i; /* identity is terminator */ |
303 |
+ |
} |
304 |
+ |
/* make neighbor lists */ |
305 |
+ |
for (r = 0; r < NRED; r++) |
306 |
+ |
for (g = 0; g < NGRN; g++) |
307 |
+ |
for (b = 0; b < NBLU; b++) { |
308 |
+ |
if (r < NRED-1 && histo[r][g][b] != histo[r+1][g][b]) |
309 |
+ |
addneigh(neigh, histo[r][g][b], histo[r+1][g][b]); |
310 |
+ |
if (g < NGRN-1 && histo[r][g][b] != histo[r][g+1][b]) |
311 |
+ |
addneigh(neigh, histo[r][g][b], histo[r][g+1][b]); |
312 |
+ |
if (b < NBLU-1 && histo[r][g][b] != histo[r][g][b+1]) |
313 |
+ |
addneigh(neigh, histo[r][g][b], histo[r][g][b+1]); |
314 |
+ |
} |
315 |
+ |
/* assign closest values */ |
316 |
+ |
for (r = 0; r < NRED; r++) |
317 |
+ |
for (g = 0; g < NGRN; g++) |
318 |
+ |
for (b = 0; b < NBLU; b++) |
319 |
+ |
setclosest(neigh, r, g, b); |
320 |
+ |
/* free neighbor lists */ |
321 |
+ |
for (i = 0; i < n; i++) |
322 |
+ |
free(neigh[i]); |
323 |
+ |
#undef i |
324 |
+ |
} |
325 |
+ |
|
326 |
+ |
|
327 |
+ |
static |
328 |
+ |
addneigh(nl, i, j) /* i and j are neighbors; add them to list */ |
329 |
+ |
register BYTE *nl[]; |
330 |
+ |
register int i; |
331 |
+ |
int j; |
332 |
+ |
{ |
333 |
+ |
int nc; |
334 |
+ |
char *nnl; |
335 |
+ |
register int t; |
336 |
+ |
|
337 |
+ |
for (nc = 0; nc < 2; nc++) { /* do both neighbors */ |
338 |
+ |
for (t = 0; nl[i][t] != i; t++) |
339 |
+ |
if (nl[i][t] == j) |
340 |
+ |
break; /* in list already */ |
341 |
+ |
if (nl[i][t] == i) { /* add to list */ |
342 |
+ |
nl[i][t++] = j; |
343 |
+ |
if (t % NBSIZ == 0) { /* enlarge list */ |
344 |
+ |
if ((nnl = realloc((void *)nl[i], |
345 |
+ |
t+NBSIZ)) == NULL) |
346 |
+ |
t--; |
347 |
+ |
else |
348 |
+ |
nl[i] = (BYTE *)nnl; |
349 |
+ |
} |
350 |
+ |
nl[i][t] = i; /* terminator */ |
351 |
+ |
} |
352 |
+ |
t = i; i = j; j = t; /* swap and do it again */ |
353 |
+ |
} |
354 |
+ |
} |
355 |
+ |
|
356 |
+ |
|
357 |
+ |
static unsigned |
358 |
+ |
dist(col, r, g, b) /* find distance from clrtab entry to r,g,b */ |
359 |
+ |
register BYTE col[3]; |
360 |
+ |
int r, g, b; |
361 |
+ |
{ |
362 |
+ |
register int tmp; |
363 |
+ |
register unsigned sum; |
364 |
+ |
|
365 |
+ |
tmp = col[RED]*NRED/256 - r; |
366 |
+ |
sum = tmp*tmp; |
367 |
+ |
tmp = col[GRN]*NGRN/256 - g; |
368 |
+ |
sum += tmp*tmp; |
369 |
+ |
tmp = col[BLU]*NBLU/256 - b; |
370 |
+ |
sum += tmp*tmp; |
371 |
+ |
return(sum); |
372 |
+ |
} |
373 |
+ |
|
374 |
+ |
|
375 |
+ |
static |
376 |
+ |
setclosest(nl, r, g, b) /* find index closest to color and assign */ |
377 |
+ |
BYTE *nl[]; |
378 |
+ |
int r, g, b; |
379 |
+ |
{ |
380 |
+ |
int ident; |
381 |
+ |
unsigned min; |
382 |
+ |
register unsigned d; |
383 |
+ |
register BYTE *p; |
384 |
+ |
/* get starting value */ |
385 |
+ |
min = dist(clrtab[ident=histo[r][g][b]], r, g, b); |
386 |
+ |
/* find minimum */ |
387 |
+ |
for (p = nl[ident]; *p != ident; p++) |
388 |
+ |
if ((d = dist(clrtab[*p], r, g, b)) < min) { |
389 |
+ |
min = d; |
390 |
+ |
histo[r][g][b] = *p; |
391 |
+ |
} |
392 |
+ |
} |
393 |
+ |
#endif |