ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/px/biq.c
Revision: 2.5
Committed: Sun Mar 28 20:33:13 2004 UTC (20 years ago) by schorsch
Content type: text/plain
Branch: MAIN
CVS Tags: rad3R6P1, rad3R6
Changes since 2.4: +15 -9 lines
Log Message:
Continued ANSIfication, and other fixes and clarifications.

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: biq.c,v 2.4 2003/06/30 14:59:12 schorsch Exp $";
3 #endif
4 /*
5 * biq.c - simple greyscale quantization.
6 *
7 * 9/19/88
8 */
9
10 #include <string.h>
11
12 #include "standard.h"
13 #include "ciq.h"
14
15 static void draw_grey(colormap ocm);
16
17
18
19 void
20 biq(
21 int dith, /* is dithering desired? 0=no, 1=yes */
22 int nw, /* number of colors wanted in output image */
23 int synth, /* synthesize colormap? 0=no, 1=yes */
24 colormap cm /* quantization colormap */
25 ) /* read if synth=0; always written */
26 {
27 colormap ocm;
28
29 picreadcm(ocm); /* read original picture's colormap (usually identity)*/
30
31 for (n = 0; n < nw; n++) /* also sets n to nw */
32 color[0][n] = color[1][n] = color[2][n] = (n*256L+128)/nw;
33
34 picwritecm(color);
35
36 draw_grey(ocm);
37
38 memcpy((void *)cm,(void *)color,sizeof color);
39 }
40
41 /*----------------------------------------------------------------------*/
42
43 static void
44 draw_grey(
45 colormap ocm
46 )
47 {
48 register rgbpixel *linin;
49 register pixel *linout;
50 rgbpixel intmp;
51 int outtmp;
52 int y;
53 register int x;
54
55 linin = line3alloc(xmax);
56 linout = linealloc(xmax);
57
58 for (y = 0; y < ymax; y++) {
59 picreadline3(y, linin);
60 for (x = 0; x < xmax; x++) {
61 intmp.r = ocm[0][linin[x].r];
62 intmp.g = ocm[1][linin[x].g];
63 intmp.b = ocm[2][linin[x].b];
64 outtmp = rgb_bright(&intmp);
65 linout[x] = (outtmp*n+n/2)/256;
66 }
67 picwriteline(y, linout);
68 }
69 free((void *)linin);
70 free((void *)linout);
71 }