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#include <u.h>
#include <libc.h>
#include <draw.h>
float c1 = 1.402;
float c2 = 0.34414;
float c3 = 0.71414;
float c4 = 1.772;
int
closest(int Y, int Cb, int Cr)
{
double r, g, b;
double diff, min;
int rgb, R, G, B, v, i;
int y1, cb1, cr1;
Cb -= 128;
Cr -= 128;
r = Y+c1*Cr;
g = Y-c2*Cb-c3*Cr;
b = Y+c4*Cb;
/*print("YCbCr: %d %d %d, RGB: %g %g %g\n", Y, Cb, Cr, r, g, b); */
min = 1000000.;
v = 1000;
for(i=0; i<256; i++){
rgb = cmap2rgb(i);
R = (rgb >> 16) & 0xFF;
G = (rgb >> 8) & 0xFF;
B = (rgb >> 0) & 0xFF;
diff = (R-r)*(R-r) + (G-g)*(G-g) + (B-b)*(B-b);
y1 = 0.5870*G + 0.114*B + 0.299*R;
cb1 = (B-y1)/1.772;
cr1 = (R-y1)/1.402;
if(diff < min){
/* if(Y==0 && y1!=0) */
/* continue; */
if(Y==256-16 && y1<256-16)
continue;
/* if(Cb==0 && cb1!=0) */
/* continue; */
if(Cb==256-16 && cb1<256-16)
continue;
/* if(Cr==0 && cr1!=0) */
/* continue; */
if(Cr==256-16 && cr1<256-16)
continue;
/*print("%d %d %d\n", R, G, B); */
min = diff;
v = i;
}
}
if(v > 255)
abort();
return v;
}
void
main(int argc, char *argv[])
{
int i, rgb;
int r, g, b;
double Y, Cr, Cb;
int y, cb, cr;
uchar close[16*16*16];
/*print("%d\n", closest(atoi(argv[1]), atoi(argv[2]), atoi(argv[3]))); */
/*exits("X"); */
/* ycbcrmap */
print("uint ycbcrmap[256] = {\n");
for(i=0; i<256; i++){
if(i%8 == 0)
print("\t");
rgb = cmap2rgb(i);
r = (rgb>>16) & 0xFF;
g = (rgb>>8) & 0xFF;
b = (rgb>>0) & 0xFF;
Y = 0.5870*g + 0.114*b + 0.299*r;
Cr = (r-Y)/1.402 + 128.;
Cb = (b-Y)/1.772 + 128.;
if(Y<0. || Y>=256. || Cr<0. || Cr>=256. || Cb<0. || Cb>=256.)
print("bad at %d: %d %d %d; %g %g %g\n", i, r, g, b, Y, Cb, Cr);
r = Y;
g = Cb;
b = Cr;
print("0x%.6ulX, ", (r<<16) | (g<<8) | b);
if(i%8 == 7)
print("\n");
}
print("};\n\n");
/* closestycbcr */
print("uchar closestycbcr[16*16*16] = {\n");
for(y=0; y<256; y+=16)
for(cb=0; cb<256; cb+=16)
for(cr=0; cr<256; cr+=16)
close[(cr/16)+16*((cb/16)+16*(y/16))] = closest(y, cb, cr);
if(0){
/*weird: set white for nearly white */
for(cb=128-32; cb<=128+32; cb+=16)
for(cr=128-32; cr<=128+32; cr+=16)
close[(cr/16)+16*((cb/16)+16*(255/16))] = 0;
/*weird: set black for nearly black */
for(cb=128-32; cb<=128+32; cb+=16)
for(cr=128-32; cr<=128+32; cr+=16)
close[(cr/16)+16*((cb/16)+16*(0/16))] = 255;
}
for(i=0; i<16*16*16; i++){
if(i%16 == 0)
print("\t");
print("%d,", close[i]);
if(i%16 == 15)
print("\n");
}
print("};\n\n");
exits(nil);
}
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