用imageROI来增加某范围的像素，为什么出不来图

//roi_add
#include
#include
int main(int argc, char*argv[])
{
IplImage*src;
if (argc == 7 && ((src = cvLoadImage("pic.ipg", 1)) != 0))
{

    int x = atoi(argv[2]);
    int y = atoi(argv[3]);
    int width = atoi(argv[4]);
    int height = atoi(argv[5]);
    int add = atoi(argv[6]);
    cvSetImageROI(src, cvRect(x, y, width, height));
    cvAddS(src, cvScalar(150), src);
    cvResetImageROI(src);
    cvNamedWindow("ROI_Add", 1);
    cvShowImage("ROI_Add", src);
    cvReleaseImage(&src);
    cvDestroyWindow("ROI_Add");
    cvWaitKey(0);
}
return 0;

}

http://www.cnblogs.com/chenyang920/p/5345679.html