SodhanaLibrary

JFrame frmImageZoomIn = new JFrame();
JScrollPane scrollPane = new JScrollPane();
frmImageZoomIn.getContentPane().add(scrollPane, BorderLayout.CENTER);
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
scrollPane.setViewportView(panel);

Icon imageIcon = new ImageIcon(inputImage);
label = new JLabel( imageIcon );
panel.add(label, BorderLayout.CENTER);

public void mouseWheelMoved(MouseWheelEvent e) {
    int notches = e.getWheelRotation();
    double temp = zoom - (notches * 0.2);
    // minimum zoom factor is 1.0
    temp = Math.max(temp, 1.0);
    if (temp != zoom) {
        zoom = temp;
        resizeImage();
    }
}

import java.awt.EventQueue;
import javax.imageio.ImageIO;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import java.awt.BorderLayout;
import javax.swing.JPanel;
import com.mortennobel.imagescaling.ResampleOp;
import java.awt.event.MouseWheelListener;
import java.awt.event.MouseWheelEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class ImageZoom {

    private JFrame frmImageZoomIn;
    private static final String inputImage = "C:\\my-pfl-pic.jpg"; // give image path here
    private JLabel label = null; 
    private double zoom = 1.0;  // zoom factor
    private BufferedImage image = null;
    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    ImageZoom window = new ImageZoom();
                    window.frmImageZoomIn.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     * @throws IOException 
     */
    public ImageZoom() throws IOException {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     * @throws IOException 
     */
    private void initialize() throws IOException {
        frmImageZoomIn = new JFrame();
        frmImageZoomIn.setTitle("Image Zoom In and Zoom Out");
        frmImageZoomIn.setBounds(100, 100, 450, 300);
        frmImageZoomIn.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        JScrollPane scrollPane = new JScrollPane();
        frmImageZoomIn.getContentPane().add(scrollPane, BorderLayout.CENTER);
        
        image = ImageIO.read(new File(inputImage));
        
        JPanel panel = new JPanel();
        panel.setLayout(new BorderLayout());
        
        // display image as icon 
        Icon imageIcon = new ImageIcon(inputImage);
        label = new JLabel( imageIcon );
        panel.add(label, BorderLayout.CENTER);
        
        panel.addMouseWheelListener(new MouseWheelListener() {
            public void mouseWheelMoved(MouseWheelEvent e) {
                int notches = e.getWheelRotation();
                double temp = zoom - (notches * 0.2);
                // minimum zoom factor is 1.0
                temp = Math.max(temp, 1.0);
                if (temp != zoom) {
                    zoom = temp;
                    resizeImage();
                }
            }
        });
        scrollPane.setViewportView(panel);
    }
    
    public void resizeImage() {
           System.out.println(zoom);
           ResampleOp  resampleOp = new ResampleOp((int)(image.getWidth()*zoom), (int)(image.getHeight()*zoom));
               BufferedImage resizedIcon = resampleOp.filter(image, null);
           Icon imageIcon = new ImageIcon(resizedIcon);
           label.setIcon(imageIcon);
        }


}