opencv RBG三通道的拆分及合并

#include <opencv2/opencv.hpp>
#include<opencv2/imgproc/imgproc.hpp>
#include<iostream>
using namespace std;
using namespace cv;
int main()
{
    //分离方法一，超麻烦，是官网的教程
    Mat img;
    img = imread("timg.jpg");
    Mat R(img.rows, img.cols, CV_8UC3, Scalar(0, 0, 0));
    Mat B(img.rows, img.cols, CV_8UC3, Scalar(0, 0, 0));
    Mat G(img.rows, img.cols, CV_8UC3, Scalar(0, 0, 0));
    Mat out[] = { B };
    int from_to[] = { 0,0 };
    mixChannels(&img, 1, out, 1, from_to, 1);
    imshow("1 channel", B);
    waitKey();
    out[0] = G;
    from_to[0] = 1;
    from_to[1] = 1;
    mixChannels(&img, 1, out, 1, from_to, 1);
    imshow("1 channel", G);
    waitKey();
    out[0] = R;
    from_to[0] = 2;
    from_to[1] = 2;
    mixChannels(&img, 1, out, 1, from_to, 1);
    imshow("1 channel", R);
    waitKey();
    //方法2，CSDN上的
    Mat imageROI,Combine;
    vector channels;
    // 把一个3通道图像转换成3个单通道图像
    split(img, channels);//分离色彩通道
    imageROI = channels.at(0);
    imshow("c0", imageROI);
    waitKey();
    merge(channels, Combine);
    imshow("Combine", Combine);
    waitKey();
    return 0;
}