【图像处理通道分离去除印章】

如下图所示，想要取出图像上的红色印记，我们可以采用通道分离的方法，具体如下：

#include<opencv2\opencv.hpp>
#include<string>
#include <vector>

using namespace cv;
using namespace std;

int main()
{

	Mat src = imread("234.png");
	//resize(src, src, Size(700, 500));
	Mat gray;
	cvtColor(src, gray, CV_RGB2GRAY);
	if (src.empty())
	{
		printf("fail to open image!\n");
		return -1;
	}

	// 全局二值化
	int th = 180; //阈值要根据实际情况调整
	Mat binary;
	threshold(gray, binary, th, 255, CV_THRESH_BINARY);
	vector<Mat>channels;
	split(src, channels);
	Mat red = channels[2];//按照BGR的顺序
	Mat blue = channels[0];
	Mat green = channels[1];

	Mat red_binary;
	threshold(red, red_binary, th, 255, CV_THRESH_BINARY);

	imshow("src", src);
	imshow("gray", gray);
	imshow("binary", binary);
	imshow("red channel", red);
	imshow("blue channel", blue);
	imshow("green channel", green);
	imshow("red+binary", red_binary);

	waitKey();


	return 0;
}