程序执行时间测算

   int64 st1,et1;
2    st1 = cvGetTickCount();
    const char* imagename = "lenaBG.jpg";
    //从文件中读入图像
    Mat img = imread(imagename);
6    et1 = cvGetTickCount();
8    printf("cost: %f milliseconds

", (et1-st1)/(double)cvGetTickFrequency()/1000.0);