1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4
5 float c1 = 1.402;
6 float c2 = 0.34414;
7 float c3 = 0.71414;
8 float c4 = 1.772;
9
10
11 int
closest(int Y,int Cb,int Cr)12 closest(int Y, int Cb, int Cr)
13 {
14 double r, g, b;
15 double diff, min;
16 int rgb, R, G, B, v, i;
17 int y1, cb1, cr1;
18
19 Cb -= 128;
20 Cr -= 128;
21 r = Y+c1*Cr;
22 g = Y-c2*Cb-c3*Cr;
23 b = Y+c4*Cb;
24
25 //print("YCbCr: %d %d %d, RGB: %g %g %g\n", Y, Cb, Cr, r, g, b);
26
27 min = 1000000.;
28 v = 1000;
29 for(i=0; i<256; i++){
30 rgb = cmap2rgb(i);
31 R = (rgb >> 16) & 0xFF;
32 G = (rgb >> 8) & 0xFF;
33 B = (rgb >> 0) & 0xFF;
34 diff = (R-r)*(R-r) + (G-g)*(G-g) + (B-b)*(B-b);
35 // y1 = 0.5870*G + 0.114*B + 0.299*R;
36 // cb1 = (B-y1)/1.772;
37 // cr1 = (R-y1)/1.402;
38 if(diff < min){
39 // if(Y==0 && y1!=0)
40 // continue;
41 // if(Y==256-16 && y1<256-16)
42 // continue;
43 // if(Cb==0 && cb1!=0)
44 // continue;
45 // if(Cb==256-16 && cb1<256-16)
46 // continue;
47 // if(Cr==0 && cr1!=0)
48 // continue;
49 // if(Cr==256-16 && cr1<256-16)
50 // continue;
51 //print("%d %d %d\n", R, G, B);
52 min = diff;
53 v = i;
54 }
55 }
56 if(v > 255)
57 abort();
58 return v;
59 }
60
61 #define SHIFT 5
62 #define INC (1<<SHIFT)
63
64 typedef struct Color Color;
65
66 struct Color
67 {
68 int col;
69 Color *next;
70 };
71
72 Color *col[INC*INC*INC];
73
74 void
add(int c,int y,int cb,int cr)75 add(int c, int y, int cb, int cr)
76 {
77 Color *cp;
78
79 y >>= 8-SHIFT;
80 cb >>= 8-SHIFT;
81 cr >>= 8-SHIFT;
82 cp = col[cr+INC*(cb+INC*y)];
83 while(cp != nil){
84 if(cp->col == c)
85 return;
86 cp = cp->next;
87 }
88 cp = malloc(sizeof(Color));
89 cp->col = c;
90 cp->next = col[cr+INC*(cb+INC*y)];
91 col[cr+INC*(cb+INC*y)] = cp;
92 }
93
94 void
main(void)95 main(void)
96 {
97 int y, cb, cr, n;
98 Color *cp;
99
100 for(y=0; y<256; y++){
101 for(cb=0; cb<256; cb++)
102 for(cr=0;cr<256;cr++)
103 add(closest(y, cb, cr), y, cb, cr);
104 fprint(2, "%d done\n", y);
105 }
106 for(y=0; y<INC*INC*INC; y++){
107 n = 0;
108 cp = col[y];
109 while(cp != nil){
110 n++;
111 cp = cp->next;
112 }
113 cp = col[y];
114 while(cp != nil){
115 n++;
116 print("%d ", cp->col);
117 cp = cp->next;
118 }
119 print("\n");
120 }
121 }
122