OpenCV JavaFX application to alter the sharpness of an image

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

Following is a JavaFX program with two sliders representing the alpha and beta values.

import java.awt.image.BufferedImage; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import javafx.application.Application; import javafx.beans.value.ChangeListener; import javafx.beans.value.ObservableValue; import javafx.embed.swing.SwingFXUtils; import javafx.geometry.Insets; import javafx.scene.Scene; import javafx.scene.control.Label; import javafx.scene.control.Slider; import javafx.scene.image.ImageView; import javafx.scene.image.WritableImage; import javafx.scene.layout.VBox; import javafx.stage.Stage; import javax.imageio.ImageIO; import org.opencv.core.Core; import org.opencv.core.Mat; import org.opencv.core.MatOfByte; import org.opencv.core.Size; import org.opencv.imgcodecs.Imgcodecs; import org.opencv.imgproc.Imgproc; public class SharpnessJavaFX extends Application {    double contrast = 1;    private final int rtype = -1;    double alpha = 1;    double beta = 0;    Slider slider1;    Slider slider2;    Mat src = null;    public void start(Stage stage) throws IOException {       //Loading the OpenCV core library       System.loadLibrary( Core.NATIVE_LIBRARY_NAME );       String file ="D:\Image\lamma2.jpg";       src = Imgcodecs.imread(file);       WritableImage writableImage = loadImage(src);       //Setting the image view       ImageView imageView = new ImageView(writableImage);       imageView.setX(50);       imageView.setY(25);       imageView.setFitHeight(400);       imageView.setFitWidth(550);       imageView.setPreserveRatio(true);       Label label1 = new Label("Alpha value");       //Setting the slider       slider1 = new Slider(0.1, 3, 1);       slider1.setShowTickLabels(true);       slider1.setShowTickMarks(true);       slider1.setMajorTickUnit(1);       slider1.setBlockIncrement(0.05);       //Setting the label       Label label2 = new Label();       Label label3 = new Label("Beta value");       //Setting the slider       slider2 = new Slider(-2, 2, 0);       slider2.setShowTickLabels(true);       slider2.setShowTickMarks(true);       slider2.setMajorTickUnit(1);       slider2.setBlockIncrement(.5);       //Setting the label       Label label4 = new Label();       //Listener for the slider       slider1.valueProperty().addListener(new ChangeListener<Number>() {          public void changed(ObservableValue <?extends Number>observable, Number oldValue, Number newValue){             try {                label2.setText("α-value: " + newValue);                alpha = newValue.doubleValue();                Mat dest = new Mat(src.rows(), src.cols(), src.type());                Imgproc.GaussianBlur(src, dest, new Size(0,0), 10);                Core.addWeighted(src, alpha, dest, beta, 0, dest);                imageView.setImage(loadImage(dest));             }             catch(Exception e) {                System.out.println("");             }          }       });       slider2.valueProperty().addListener(new ChangeListener<Number>() {          public void changed(ObservableValue <?extends Number>observable, Number oldValue, Number newValue){             try {                label4.setText("β-value: " + newValue);                beta = newValue.doubleValue();                Mat dest = new Mat(src.rows(), src.cols(), src.type());                Imgproc.GaussianBlur(src, dest, new Size(0,0), 10);                Core.addWeighted(src, alpha, dest, beta, 0, dest);                imageView.setImage(loadImage(dest));             }             catch(Exception e) {                System.out.println("");             }          }       });       //VBox to arrange all the three components       VBox vbox = new VBox();       vbox.setPadding(new Insets(20));       vbox.setSpacing(10);       vbox.getChildren().addAll(label1, slider1, label2, imageView, label3, slider2, label4);       //Creating a scene object       Scene scene = new Scene(vbox, 600, 560);       stage.setTitle("Altering the sharpness");       stage.setScene(scene);       stage.show();    }    public WritableImage loadImage(Mat image) throws IOException {       MatOfByte matOfByte = new MatOfByte();       Imgcodecs.imencode(".jpg", image, matOfByte);       //Storing the encoded Mat in a byte array       byte[] byteArray = matOfByte.toArray();       //Displaying the image       InputStream in = new ByteArrayInputStream(byteArray);       BufferedImage bufImage = ImageIO.read(in);       System.out.println("Image Loaded");       WritableImage writableImage = SwingFXUtils.toFXImage(bufImage, null);       return writableImage;    }    public static void main(String args[]) {       launch(args);    } }

Input

Output