How to alter the sharpness of an image using Java OpenCV library?

Sharpening an image is the opposite of blur. To alter the sharpness of an image using the OpenCV library, you need to smooth/blur it using the Gaussian filter and subtract the smoothed version from the original image.

Example

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.Size;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
public class AlteringSharpness {
   public static void main (String[] args) {
      //Loading the OpenCV core library
      System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
      //Reading the Image from the file
      String file ="D:\Image\lamma1.jpg";
      Mat src = Imgcodecs.imread(file, Imgcodecs.IMREAD_COLOR);
      //Creating an empty matrix
      Mat dest = new Mat(src.rows(), src.cols(), src.type());
      Imgproc.GaussianBlur(src, dest, new Size(0,0), 10);
      Core.addWeighted(src, 1.5, dest, -0.5, 0, dest);
      // Writing the image
      Imgcodecs.imwrite("D:\Image\altering_sharpness_100.jpg", dest);
   }
}

Input

Output