opencv png和jpg的叠加

char *bgFile = "C:/C_Project/HandTraining/Debug/res/bg.jpg";
    FILE *file = fopen(bgFile, "r");
    if (file == NULL){
        cout << "bg.jpg文件不存在..." << endl;
        return -1;
    }
    char *handFile = "C:/C_Project/HandTraining/Debug/res/hand002.png";
    file = fopen(handFile, "r");
    if (file == NULL){
        cout << "hand0001.png文件不存在..." << endl;
        return -1;
    }
    Mat image = imread(bgFile);
    Mat hand = imread(handFile);
    Mat mask = imread(handFile,0);
    Mat imageROI = image(Rect(30, 120, hand.cols, hand.rows));
    
    hand.copyTo(imageROI,mask);
    
    
    //addWeighted(imageROI, 1.0, hand, 0.3, 0, imageROI);
    cv::imwrite("C:/C_Project/HandTraining/Debug/res/result.jpg", image);
    
    imshow("result", image);
    waitKey();
    cv::destroyAllWindows();