opencv加载,修改,保存图像

#include <opencv2/opencv.hpp>
#include <iostream>
#include <math.h>
using namespace cv;
using namespace std;

int main()
{
    //原图
    Mat src1 = imread(".//pic//test.jpg",IMREAD_UNCHANGED);
    //灰度图
    Mat src2 = imread(".//pic//test.jpg", IMREAD_GRAYSCALE);
    //RGB图
    Mat src3 = imread(".//pic//test.jpg", IMREAD_COLOR );
    if (src1.empty() || src2.empty() || src3.empty())
    {
        cout << "找不到图像" << endl;
        return -1;
    }
    
    namedWindow("opencv startup", CV_WINDOW_AUTOSIZE);
    imshow("原图", src1);
    imshow("灰度图", src2);
    imshow("RGB图", src3);

    //转化成灰度图
    Mat output;
    /*cvtColor(src3, output, CV_BGR2GRAY);
    imshow("RGB图", src3);
    imshow("RGBTo灰度", output);*/

    //颜色空间转换
    cvtColor(src3, output,CV_BGR2HLS);
    imshow("RGB图", src3);
    imshow("颜色空间转换", output);
    //图像保存
    imwrite("./store.png", output); 

    waitKey();
    return 0;
}