Desktop: OpenCV Gui change every pixel

Goal

OpenCV_BrightnessChgEveryPixel.java

import java.awt.EventQueue;
import java.awt.image.BufferedImage;

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;

public class OpenCV_BrightnessChgEveryPixel {

	static {System.loadLibrary(Core.NATIVE_LIBRARY_NAME);}
	private JFrame frmJavaSwing;
	double alpha =2;
	double beta =50;
	
	public static void main(String[] args) {
		EventQueue.invokeLater(new Runnable() {
			
			@Override
			public void run() {
				try {
					OpenCV_BrightnessChgEveryPixel window = new OpenCV_BrightnessChgEveryPixel();
					window.frmJavaSwing.setVisible(true);
				}catch (Exception e) {
					e.printStackTrace();
				}
				
			}
		});

	}

	public OpenCV_BrightnessChgEveryPixel() {
		init();
	}

	
	private void init() {
		final Mat src = Imgcodecs.imread("D:\\projects\\Java\\OpenCV_Samples\\resource\\imgs\\clean.jpg ");
		
		BufferedImage image = matToBufferedImage(matConvertTo(src, alpha, beta));
		
		frmJavaSwing = new JFrame();
		frmJavaSwing.setTitle("Java Swing");
		frmJavaSwing.setBounds(100,100,520,520);
		frmJavaSwing.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frmJavaSwing.getContentPane().setLayout(null);
		
		final JLabel showAlphaValue = new JLabel("2");
		showAlphaValue.setBounds(250,10,46,15);
		frmJavaSwing.getContentPane().add(showAlphaValue);
		
		final JLabel showBetaValue = new JLabel("50");
		showBetaValue.setBounds(250,35,46,15);
		frmJavaSwing.getContentPane().add(showBetaValue);
		
		final JLabel lblNewLabel = new JLabel();
		lblNewLabel.setBounds(10,68,438,438);
		lblNewLabel.setIcon(new ImageIcon(image));
		frmJavaSwing.getContentPane().add(lblNewLabel);
		
		final JSlider slider_beta = new JSlider();
		slider_beta.setMaximum(300);
		slider_beta.setBounds(47, 33, 200, 25);
		frmJavaSwing.getContentPane().add(slider_beta);
		
		
		final JSlider slider_alpha = new JSlider();
		slider_alpha.setValue(2);
		slider_alpha.addChangeListener(new ChangeListener() {
			
			@Override
			public void stateChanged(ChangeEvent e) {
				showAlphaValue.setText(slider_alpha.getValue()+"");
				BufferedImage newImage = matToBufferedImage(matConvertTo(src,slider_alpha.getValue(),slider_beta.getValue()));
				lblNewLabel.setIcon(new ImageIcon(newImage));
				
			}
		});
		
		slider_alpha.setBounds(47,10,100,25);
		frmJavaSwing.getContentPane().add(slider_alpha);
		
		JLabel lblAlpha = new JLabel("Alpha");
		lblAlpha.setBounds(10,20,46,15);
		frmJavaSwing.getContentPane().add(lblAlpha);
		
		JLabel lblBeta = new JLabel("beta");
		lblBeta.setBounds(10,45,46,15);
		frmJavaSwing.getContentPane().add(lblBeta);
		
		slider_beta.addChangeListener(new ChangeListener() {
			
			@Override
			public void stateChanged(ChangeEvent e) {
				showBetaValue.setText(slider_beta.getValue()+"");
				BufferedImage newImage = matToBufferedImage(matConvertTo(src, alpha, beta));
				lblNewLabel.setIcon(new ImageIcon(newImage));
			}
		});
	}
	
	public Mat matConvertTo(Mat source,double alpha,double beta){
		
		 Mat destination=new Mat(source.rows(),source.cols(),source.type());
		 for(int j=0;j<source.rows();j++){
			 for(int i=0;i<source.cols();i++){
				 double[] temp=source.get(j, i);
				 temp[0]=temp[0]*alpha+beta;
				 temp[1]=temp[1]*alpha+beta;
				 temp[2]=temp[2]*alpha+beta;
				 destination.put(j, i,temp);
			 }
		 }         
		return destination;
		
	}
	
	 public BufferedImage matToBufferedImage(Mat matrix) {  
		    int cols = matrix.cols();  
		    int rows = matrix.rows();  
		    int elemSize = (int)matrix.elemSize();  
		    byte[] data = new byte[cols * rows * elemSize];  
		    int type;  
		    matrix.get(0, 0, data);  
		    switch (matrix.channels()) {  
		      case 1:  
		        type = BufferedImage.TYPE_BYTE_GRAY;  
		        break;  
		      case 3:  
		        type = BufferedImage.TYPE_3BYTE_BGR;  
		        // bgr to rgb  
		        byte b;  
		        for(int i=0; i<data.length; i=i+3) {  
		          b = data[i];  
		          data[i] = data[i+2];  
		          data[i+2] = b;  
		        }  
		        break;  
		      default:  
		        return null;  
		    }  
		    BufferedImage image2 = new BufferedImage(cols, rows, type);  
		    image2.getRaster().setDataElements(0, 0, cols, rows, data);  
		    return image2;  
		  }  
}

Result