[code]自动白平衡white blance

//2013.10.24 
//eageldiao
//自动白平衡

CvScalar rgb;
rgb=cvAvg(src);

#ifdef COLOR_GW       //灰度世界假设（R，= R*K/Ravg ,其中，K=128 or （Ravg+Gavg+Bavg）/3 ）
int KK,gw_k;
//KK=rgb.val[0];
//if (rgb.val[1]>KK)KK=rgb.val[1];
//if (rgb.val[2]>KK)KK=rgb.val[2];
//gw_k=KK;                          //K=max(Ravg+Gavg+Bavg)
//gw_k=(rgb.val[0]+rgb.val[1]+rgb.val[2])/3;//K=mean(Ravg+Gavg+Bavg)
gw_k=120;                       //K=128;    
printf( "K=%d;BGR(%f,%f,%f)
",gw_k,rgb.val[0],rgb.val[1],rgb.val[2]);      //显示RGB三通道的均值。

#endif

#ifdef COLOR_REMAIN
float gw_k, rgbavg, KK;
//rgbavg=(rgb.val[0]+rgb.val[1]+rgb.val[2])/3;
//KK=rgb.val[0]/rgbavg;
//if(rgb.val[1]/rgbavg>KK)KK=rgb.val[1]/rgbavg;
//if(rgb.val[2]/rgbavg>KK)KK=rgb.val[2]/rgbavg;
//gw_k=KK;            
gw_k=1.3;
printf( "K=%f(%f,%f,%f)
",gw_k,rgb.val[0],rgb.val[1],rgb.val[2]);      //显示RGB三通道的均值。

#endif

for(y=0;y<height;y++)
{
unsigned char *srcrow= (unsignedchar*)(src->imageData+y*src->widthStep);
for (x=0;x<width;x++)
{  
#ifdef COLOR_GW                            //使用一般的灰度世界的方法
srcrow[3*x]=srcrow[3*x]*gw_k/rgb.val[0]>255 ? 255:srcrow[3*x]*gw_k/rgb.val[0];
srcrow[3*x+1]=srcrow[3*x+1]*gw_k/rgb.val[1]>255 ?255: srcrow[3*x+1]*gw_k/rgb.val[1];
srcrow[3*x+2]=srcrow[3*x+2]*gw_k/rgb.val[2]>255 ?255: srcrow[3*x+2]*gw_k/rgb.val[2];
#endif

#ifdef COLOR_REMAIN                         //使用颜色保持的增强方法，R'/R=G'/G=B'/B=gw_k;
srcrow[3*x]=srcrow[3*x]*gw_k>255 ?255: srcrow[3*x]*gw_k;
srcrow[3*x+1]=srcrow[3*x+1]*gw_k>255 ?255: srcrow[3*x+1]*gw_k;
srcrow[3*x+2]=srcrow[3*x+2]*gw_k>255 ?255: srcrow[3*x+2]*gw_k;
#endif
}
}