Desktop : OpenCV merge Picture

<h5>Goal</h5>
Test OpenCV merge two pictures.

```OpenCV_MergeUseAddWeight.java
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;
import java.awt.image.BufferedImage;

public class OpenCV_MergeUseAddWeight {

    static{ System.loadLibrary(Core.NATIVE_LIBRARY_NAME); }
    private JFrame frmjavaSwing;
    double alpha = 0.0;
    double beta = 0.0;
    double gamma=1;

    /**
     *  Launch the application.
     */
    public static void main(String[] args){
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    OpenCV_MergeUseAddWeight window = new OpenCV_MergeUseAddWeight();
                    window.frmjavaSwing.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public OpenCV_MergeUseAddWeight(){
        init();
    }

    public void  init(){
        final Mat source1 = Imgcodecs.imread("D:\\projects\\Java\\OpenCV_Samples\\resource\\imgs\\lena.jpg");
        final Mat source2 = Imgcodecs.imread("D:\\projects\\Java\\OpenCV_Samples\\resource\\imgs\\baboon.jpg");

        BufferedImage image=matToBufferedImage(merge(source1,source2,alpha,beta,gamma));

        frmjavaSwing = new JFrame();
        frmjavaSwing.setTitle("opencv Merge�m��");
        frmjavaSwing.setBounds(100, 100, 520, 550);
        frmjavaSwing.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frmjavaSwing.getContentPane().setLayout(null);

        final JLabel showAlphaValue = new JLabel("0");
        showAlphaValue.setBounds(260, 10, 29, 15);
        frmjavaSwing.getContentPane().add(showAlphaValue);

        final JLabel showBetaValue = new JLabel("0");
        showBetaValue.setBounds(259, 35, 29, 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.setValue(0);
        slider_Beta.setMaximum(20);
        slider_Beta.setBounds(57, 35, 200, 25);
        frmjavaSwing.getContentPane().add(slider_Beta);

        final JSlider slider_Gamma = new JSlider();
        slider_Gamma.setMaximum(200);
        slider_Gamma.setValue(0);
        slider_Gamma.setBounds(290, 35, 115, 25);
        frmjavaSwing.getContentPane().add(slider_Gamma);


        final JSlider slider_Alpha = new JSlider();
        slider_Alpha.setMaximum(20);
        slider_Alpha.setValue(0);
        slider_Alpha.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                //System.out.println(slider_Alpha.getValue()/10);
                showAlphaValue.setText((float)slider_Alpha.getValue()/10+"");
                BufferedImage newImage=matToBufferedImage(merge(source1,source2,(float)slider_Alpha.getValue()/10,(float)slider_Beta.getValue()/10,slider_Gamma.getValue()));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
        slider_Alpha.setBounds(57, 10, 200, 25);
        frmjavaSwing.getContentPane().add(slider_Alpha);

        JLabel lblAlpha = new JLabel("Alpha");
        lblAlpha.setBounds(10, 20, 46, 15);
        frmjavaSwing.getContentPane().add(lblAlpha);

        JLabel lblBetaval = new JLabel("Beta");
        lblBetaval.setBounds(10, 45, 46, 15);
        frmjavaSwing.getContentPane().add(lblBetaval);

        JLabel lblGamma = new JLabel("Gamma");
        lblGamma.setBounds(290, 10, 46, 15);
        frmjavaSwing.getContentPane().add(lblGamma);

        final JLabel showTypeValue = new JLabel("0");
        showTypeValue.setBounds(415, 35, 19, 15);
        frmjavaSwing.getContentPane().add(showTypeValue);

        slider_Gamma.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                showTypeValue.setText(slider_Gamma.getValue()+"");
                BufferedImage newImage=matToBufferedImage(merge(source1,source2,(float)slider_Alpha.getValue()/10,(float)slider_Beta.getValue()/10,slider_Gamma.getValue()));
                lblNewLabel.setIcon(new ImageIcon(newImage));

            }
        });

        slider_Beta.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                showBetaValue.setText((float)slider_Beta.getValue()/10+"");
                BufferedImage newImage=matToBufferedImage(merge(source1,source2,(float)slider_Alpha.getValue()/10,(float)slider_Beta.getValue()/10,slider_Gamma.getValue()));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
    }

    public Mat merge(Mat source1,Mat source2,double alpha,double beta,double gamma){

        Mat destination=new Mat(source1.rows(),source1.cols(),source1.type());
        Core.addWeighted(source1, alpha, source2, beta, gamma, destination);
        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;
    }
}

```

<h5>Result</h5>
![opencv_merge_images.JPG](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/276243/8ce3be24-f330-f90a-077b-6f87019c6dce.jpeg)