鼠标马赛克图像部分区域

这是一个简单的马赛克程序，利用选定矩形区域的平均值代替该区域各点的像素值。大家有没有更好的方法马赛克呢？

 #include <cv.h>
 #include <highgui.h>
 #pragma comment( lib, "cv.lib" )
 #pragma comment( lib, "cxcore.lib" )
 #pragma comment( lib, "highgui.lib" )
 IplImage* org = 0;
 IplImage* img = 0;
 IplImage* tmp = 0;
 IplImage* dst = 0;
 int foo=6;
 void on_mouse( int event, int x, int y, int flags, void* ustc)
 {
     CvPoint p0;
     CvPoint p1;
     if( event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))
     {
         img=cvCloneImage(tmp);
         cvResetImageROI(img);
         if(x<foo)
         {
             if(y<foo)
             {
                 p0=cvPoint(0,0);
                 p1=cvPoint(2*foo,2*foo);
             }
             else if(y>img->height-foo)
             {
                 p0=cvPoint(0,img->height-2*foo);
                 p1=cvPoint(2*foo,img->height);
             }
             else
             {
                 p0=cvPoint(0,y-foo);
                 p1=cvPoint(2*foo,y+foo);
             }
         }
         else if(x>img->width-foo)
         {
             if(y<foo)
             {
                 p0=cvPoint(img->width-2*foo,0);
                 p1=cvPoint(img->width,2*foo);
             }
             else if(y>img->height-foo)
             {
                 p0=cvPoint(img->width-2*foo,img->height-2*foo);
                 p1=cvPoint(img->width,img->height);
             }
             else
             {
                 p0=cvPoint(img->width-2*foo,y-foo);
                 p1=cvPoint(img->width,y+foo);
             }
         }
         else
         {
             if(y<foo)
             {
                 p0=cvPoint(x-foo,0);
                 p1=cvPoint(x+foo,2*foo);
             }
             else if(y>img->height-foo)
             {
                 p0=cvPoint(x-foo,img->height-2*foo);
                 p1=cvPoint(x+foo,img->height);
             }
             else
             {
                 p0=cvPoint(x-foo,y-foo);
                 p1=cvPoint(x+foo,y+foo);
             }
         }
         cvRectangle(img,p0,p1,CV_RGB(0,255,0));
         cvShowImage( "img", img );
     }
     else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))
     {
         if(x<foo)
         {
             if(y<foo)
             {
                 p0=cvPoint(0,0);
                 p1=cvPoint(2*foo,2*foo);
             }
             else if(y>img->height-foo)
             {
                 p0=cvPoint(0,img->height-2*foo);
                 p1=cvPoint(2*foo,img->height);
             }
             else
             {
                 p0=cvPoint(0,y-foo);
                 p1=cvPoint(2*foo,y+foo);
             }
         }
         else if(x>img->width-foo)
         {
             if(y<foo)
             {
                 p0=cvPoint(img->width-2*foo,0);
                 p1=cvPoint(img->width,2*foo);
             }
             else if(y>img->height-foo)
             {
                 p0=cvPoint(img->width-2*foo,img->height-2*foo);
                 p1=cvPoint(img->width,img->height);
             }
             else
             {
                 p0=cvPoint(img->width-2*foo,y-foo);
                 p1=cvPoint(img->width,y+foo);
             }
         }
         else
         {
             if(y<foo)
             {
                 p0=cvPoint(x-foo,0);
                 p1=cvPoint(x+foo,2*foo);
             }
             else if(y>img->height-foo)
             {
                 p0=cvPoint(x-foo,img->height-2*foo);
                 p1=cvPoint(x+foo,img->height);
             }
             else
             {
                 p0=cvPoint(x-foo,y-foo);
                 p1=cvPoint(x+foo,y+foo);
             }
         }
         dst=cvCloneImage(tmp);
         cvSetImageROI(dst,cvRect(p0.x,p0.y,p1.x-p0.x,p1.y-p0.y));
         CvScalar mean=cvAvg(dst);
         cvSet(dst,mean);
         cvResetImageROI(dst);
         tmp=cvCloneImage(dst);
         cvRectangle(dst,p0,p1,CV_RGB(0,255,0));
         cvShowImage( "img", dst );
     }
 }
 int main()
 {
     org=cvLoadImage("lena.jpg",1);
     img=cvCloneImage(org);
     tmp=cvCloneImage(org);
     dst=cvCloneImage(org);
     cvNamedWindow("img",1);
     cvSetMouseCallback( "img", on_mouse, 0 );
     cvShowImage("img",img);
     cvWaitKey(0);
     cvDestroyAllWindows();
     cvReleaseImage(&org);
     cvReleaseImage(&img);
     cvReleaseImage(&tmp);
     cvReleaseImage(&dst);
     return 0;
 }

效果图如下，这里马赛克了lena图的左眼。