OpenCV3读取、写入和保存图像

需要说明的是在OpenCV3中已经将imread()和imwrite()函数转移到imgcodecs模块中，因此读写图像时，需要包含imgcodecs.hpp头文件，但是highgui.hpp头文件中已经包含了该头文件，因此不用再显式包含了。

#include <iostream>

#include <string>

using namespace std;

// OpenCV includes

#include <opencv2/core/core.hpp>

#include <opencv2/highgui/highgui.hpp>

using namespace cv;

int main(int argc, const char** argv)

{

    // Read images

    Mat color = imread("../images/eating.jpg");

    Mat gray  = imread("../images/eating.jpg", );

    // Write images

    imwrite("gray.jpg", gray);

    // Get same pixel with opencv function

    int myRow = color.cols - ;

    int myCol = color.rows - ;

    Vec3b pixel = color.at<Vec3b>(myRow, myCol);

    cout << "Pixel Value (B, G, R): ("

         << (int)pixel[] << ", "

         << (int)pixel[] << ", "

         << (int)pixel[] << ")" << endl;

    // Show images

    imshow("Color Image", color);

    imshow("Gray Image", gray);

    // Wait for any key

    waitKey();

    return ;

}

显示的图片效果如下：