Flip an image in opencv by using flip function

Syntax:
C++: void flip(InputArray src, OutputArray dst, int flipCode)

Flips a 2D array around vertical, horizontal, or both axes.

Parameters:
src – input array.
dst – output array of the same size and type as src.
flipCode – a flag to specify how to flip the array.

 0 means flipping around the x-axis
 positive value (for example, 1) means flipping around y-axis
 Negative value (for example, -1) means flipping around both axes

Here is the code of flipping the image:

// OpenCV Image Flipping Tutorial 
#include <opencv2/core/core.hpp> 
#include <opencv2/highgui/highgui.hpp> 
#include <iostream>

using namespace cv;
using namespace std;

int main()
{
  double alpha, beta; 

 Mat src1,src2;
 // Read image (same size, same type )
 src1 = imread("C:\Users\arjun\Desktop\flipsrc.jpg");//Linux.jpg");//atom.jpg");//"Linux.jpg"); //f1.jpg
 
 if( !src1.data ) { printf("Error loadind src1 n"); return -1;}

 //Create Window
 namedWindow("Original Image", CV_WINDOW_AUTOSIZE );
 imshow( "Original Image", src1 );
 
 flip(src1,src2,0);
 namedWindow("Flip-x-axis", CV_WINDOW_AUTOSIZE );
 imshow( "Flip-x-axis", src2 );
 imwrite( "C:\Users\arjun\Desktop\flipXaxis.jpg",src2);


 flip(src1,src2,1);
 namedWindow("Flip-y-axis", CV_WINDOW_AUTOSIZE );
 imshow( "Flip-y-axis", src2 );
 imwrite( "C:\Users\arjun\Desktop\flipYaxis.jpg",src2);

 flip(src1,src2,-1);
 namedWindow("Flip-z-axis", CV_WINDOW_AUTOSIZE );
 imshow( "Flip-z-axis", src2 );
 imwrite( "C:\Users\arjun\Desktop\flipZaxis.jpg",src2);

 waitKey(0);
 return 0;
 
}

Input Image:

Output:
Flipping around the X axis

Flipping around the Y axis

Flipping around both the axis

We can also put the flip function under for loop and obtain the three flipping of an image as shown below:

// OpenCV Image Flipping Tutorial 
#include <opencv2/core/core.hpp> 
#include <opencv2/highgui/highgui.hpp> 
#include <iostream>

using namespace cv;
using namespace std;

int main()
{
  double alpha, beta; 

 Mat src1,src2;
 // Read image (same size, same type )
 src1 = imread("C:\\Users\\arjun\\Desktop\\arj.jpg");
 
 if( !src1.data ) { printf("Error loading src1 n"); return -1;}
 
 //Create Window
 namedWindow("Original Image", CV_WINDOW_AUTOSIZE );
 imshow( "Original Image", src1 );
 for(int i=-1;i<2;i++)
 {
 flip(src1,src2,i);
 namedWindow("Flip", CV_WINDOW_AUTOSIZE );
 imshow( "Flip", src2 );
 waitKey(5000);
  }
 waitKey(0);
 return 0;
 }

Output: