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