访问cv::Mat数据

	for (int i = 0; i < mask_glass.rows; i++) {
		for (int j = 0; j < mask_glass.cols; j++) {
			uchar a= mask_glass0.at<uchar>(i, j);
			mask_glass.at<uchar>((i, j), 0) = mask_glass0.at<uchar>(i, j);
			mask_glass.at<uchar>((i, j), 1) = mask_glass0.at<uchar>(i, j);
			mask_glass.at<uchar>((i, j), 2) = mask_glass0.at<uchar>(i, j);
		}
	}