int i,j,k,sum;
        int width,height,dep;
        width=currentimage->width;
        height=currentimage->height;
        dep=currentimage->widthStep/currentimage->width;
        for (i=0;i<height;i++)
        {
            for (j=0;j<width;j++)
            {
                sum=0;
                for (k=0;k<dep;k++)
                {
                    //currentimage->imageData[i*currentimage->widthStep+dep*j+k]-=lastimage->imageData[i*currentimage->widthStep+dep*j+k];
                    sum+=currentimage->imageData[i*currentimage->widthStep+dep*j+k];
                }
                for (k=0;k<dep;k++)
                {
                    //currentimage->imageData[i*currentimage->widthStep+dep*j+k]-=lastimage->imageData[i*currentimage->widthStep+dep*j+k];
                    currentimage->imageData[i*currentimage->widthStep+dep*j+k]=(uchar)(sum/3);
                }
            }
        }