int GenerateTransparentMask()

{

    Mat mat = imread("test.jpg");

    if (mat.empty())

        return -;

    Size size = mat.size();

    cv::Mat mask ( size, mat.type() );

    mat.copyTo(mask);

    //cv::Mat mask(mat);    //Can not work, becuase mask will be just a copy of mat, if draw on mask, means draw on mat too

    Rect rect(, , , );

    rectangle(mask, rect, Scalar(, , ), CV_FILLED, CV_AA, );

    double alpha = 0.3;

    double beta = 1.0 - alpha;

    cv::addWeighted(mask, alpha, mat, beta, 0.0, mat);

    cvNamedWindow("Result");

    imshow("Result", mat);

    cvWaitKey(); //wait for a key press

    return ;

}

int GenerateTransparentMask()

{

    const Mat mat = imread("DetectingContours.jpg");

    if (mat.empty())

        return -;

    imshow("origianl", mat);

    Size size = mat.size();

    cv::Mat copy ( size, mat.type() );

    mat.copyTo ( copy );

    //cv::Mat mask(mat);    //Can not work, becuase mask will be just a copy of mat, draw on mask, means draw on mat too

    cv::Mat mask(size, CV_8U);　　//mask must be CV_8U

    mask.setTo(Scalar());

    Rect rect(, , , );

    rectangle(mask, rect, Scalar(, , ), CV_FILLED, CV_AA, );

    rectangle(mask, Rect(, , , ), Scalar(, , ), CV_FILLED);

    circle(mask, Point(, ), , Scalar(), CV_FILLED);

    copy.setTo(Scalar(, , ), mask);

    //imshow("copy", copy);

    double alpha = 0.5;

    double beta = 1.0 - alpha;

    cv::Mat result(size, mat.type());

    cv::addWeighted(copy, alpha, mat, beta, 0.0, result);

    cvNamedWindow("Result");

    imshow("Result", result);

    cvWaitKey(); //wait for a key press

    return ;

}