The flip() method of the Core class of OpenCV flips an image along the x/y axis. This method accepts −
A source matrix congaing the data of the original image.
An empty destination matrix to hold the data of the resultant image.
A flip code to specify the direction of the image (0 –x axis, +ve – y axis, – ve both the axes).
To flip an image −
Load the OpenCV core native library, using the loadLibrary() method.
Read the contents of the image file to a matrix using the imread() method.
Create an empty matric to hold the result.
Invoke the flip() method by passing the above-created matrices.
Create an image using the imwrite() method, bypassing the destination matrix as a parameter.
Example
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
public class ChangingOrientation {
public static void main(String args[]) {
//Loading the OpenCV core library
System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
//Reading the Image from the file and storing it in to a Matrix object
String file ="D:\\Images\\cat.jpg";
Mat src = Imgcodecs.imread(file);
//Creating an empty matrix to store the result
Mat dst = new Mat();
//Changing the orientation of an image
Core.flip(src, dst, -1);
//Writing the image
Imgcodecs.imwrite("D:\\Images\\flipping.jpg", dst);
System.out.println("Image Processed");
}
}Input
Output
