C++OenCV——将灰度图特定像素区域的像素值进行标记

由于如果要在灰度图上进行标记效果不好，而且比较模糊。因此要想在图像得到一个比较好的标记，我们选择把灰度图转化为伪灰度图的三通道图像上进行标记。

Mat QuickDemo::grayImage_mask_print(Mat& image)
{
	// 输入图像image是单通道的灰度图
	int h = image.rows;
	int w = image.cols;
	int dims = image.channels();

	// 将单通道灰度图转换成为伪灰度图的三通道图像
	Mat image_bgr;
	cvtColor(image, image_bgr, COLOR_GRAY2BGR);

	for (int row = 0; row < h; row++) 
	{
		for (int col = 0; col < w; col++) {
			if (image.at<uchar>(row, col) > 0 && image.at<uchar>(row, col) < 40) {
				image_bgr.at<Vec3b>(row, col)[0] = 0;
				image_bgr.at<Vec3b>(row, col)[1] = 0;
				image_bgr.at<Vec3b>(row, col)[2] = 255;
			}
		}
	}
	return image_bgr;
	
}

测试函数如下：

int main(int argc, char** argv) {
	Mat src = imread("D:\\testImage\\4.BMP");
	Mat pt = src;
	if (src.empty()) {
		printf("could not load image...");
		return -1;
	}
	imshow("原图", src);
	Mat image_gray;
	cvtColor(src, image_gray, COLOR_BGR2GRAY);

	Mat image_bgr;
	cvtColor(image_gray, image_bgr, COLOR_GRAY2BGR);

	namedWindow("输入窗口", WINDOW_FREERATIO);
	imshow("输入窗口", image_bgr);

	int gray_dims = image_gray.channels();
	int bgr_dims = image_bgr.channels();

	cout << "image_gray的通道数：" << gray_dims << endl;
	cout << "image_bgr的通道数：" << bgr_dims << endl;
	QuickDemo qd;

	Mat new_image = qd.grayImage_mask_print(image_gray);
	namedWindow("new_image", WINDOW_FREERATIO);
	imshow("new_image", new_image);
    waitKey(0);
	return 0;
}

  

               

上图分别是通道数图、原图、灰度图以及摸一个像素的标记图