使用OpenCV保存图像和视频

保存图像

    #include 
    #include 
    
    using namespace cv;
    using namespace std;
    
    int main(int argc, char** argv)
    {
    	// Read the image file
    	Mat image = imread("/home/CORPUSERS/xp025362/Pictures/opencv_test1.png");
    
    	// Check for failure
    	if (image.empty())
    	{
    		cout << "Could not open or find the image" << endl;
    		cin.get(); //wait for any key press
    		return -1;
    	}
    
    	/*
    	   Make changes to the image as necessary
    	   e.g.  
    	   1. Change brightness/contrast of the image
    	   2. Smooth/Blur image
    	   3. Crop the image
    	   4. Rotate the image
    	   5. Draw shapes on the image
    	   */
    
    	bool isSuccess = imwrite("/home/CORPUSERS/xp025362/software/opencv-3.2.0/wxt/save/wxt.jpg", image); //write the image to a file as JPEG 
    	//bool isSuccess = imwrite("D:/MyImage.png", image); //write the image to a file as PNG
    	if (isSuccess == false)
    	{
    		cout << "Failed to save the image" << endl;
    		cin.get(); //wait for a key press
    		return -1;
    	}
    
    	cout << "Image is succusfully saved to a file" << endl;
    
    	String windowName = "The Saved Image"; //Name of the window
    	namedWindow(windowName); // Create a window
    	imshow(windowName, image); // Show our image inside the created window.
    
    	waitKey(0); // Wait for any keystroke in the window
    
    	destroyWindow(windowName); //destroy the created window
    
    	return 0;
    }

保存视频

    #include 
    #include  
    #include 
    
    using namespace cv;
    using namespace std;
    
    int main(int argc, char* argv[])
    {
    	//Open the default video camera
    	VideoCapture cap("/home/CORPUSERS/xp025362/Videos/dog.mp4");
    
    	// if not success, exit program
    	if (cap.isOpened() == false)
    	{
    		cout << "Cannot open the video camera" << endl;
    		cin.get(); //wait for any key press
    		return -1;
    	}
    
    	int frame_width = static_cast<int>(cap.get(CV_CAP_PROP_FRAME_WIDTH)); //get the width of frames of the video
    	int frame_height = static_cast<int>(cap.get(CV_CAP_PROP_FRAME_HEIGHT)); //get the height of frames of the video
    
    	Size frame_size(frame_width, frame_height);
    	int frames_per_second = 10;
    
    	//Create and initialize the VideoWriter object 
    	int codec = CV_FOURCC('M','J','P','G');
    	VideoWriter oVideoWriter("/home/CORPUSERS/xp025362/software/opencv-3.2.0/wxt/save/wxt.avi", 
    			codec, frames_per_second, frame_size, true); 
    
    	//If the VideoWriter object is not initialized successfully, exit the program
    	if (oVideoWriter.isOpened() == false) 
    	{
    		cout << "Cannot save the video to a file" << endl;
    		cin.get(); //wait for any key press
    		return -1;
    	}
    
    	string window_name = "My Camera Feed";
    	namedWindow(window_name); //create a window called "My Camera Feed"
    
    	while (true)
    	{
    		Mat frame;
    		bool isSuccess = cap.read(frame); // read a new frame from the video camera
    
    		//Breaking the while loop if frames cannot be read from the camera
    		if (isSuccess == false)
    		{
    			cout << "Video camera is disconnected" << endl;
    			cin.get();//Wait for any key press
    			break;
    		}
    
    		//write the video frame to the file
    		oVideoWriter.write(frame); 
    
    		//show the frame in the created window
    		imshow(window_name, frame);
    		if (waitKey(10) == 27)
    		{
    			cout << "Esc key is pressed by the user. Stopping the video" << endl;
    			break;
    		}
    	}
    
    	//Flush and close the video file
    	oVideoWriter.release();
    
    	return 0;
    }

这里两个例子比较简单，相信大家都能看懂。 那么在使用不同版本的OpenCV编译时，会抛出比如我这样
‘CV_FOURCC’ is not a member of ‘cv::VideoWriter’ 的error，大家可以参考/sample/下的示例code，看下你自己所用的版本对应的member怎么使用，可以很快解决问题。
关于codec的参数含义可以参考：FOURCC
记录下第二天的学习路程，小白一枚有问题可以互相交流～