Desktop : OpenCV Change Size Use GassianPryamid

<h5>Goal</h5>
Test OpenCV GassianPryamid scale a image.

```OpenCV_ChangeSizeUseGassianPryamid.java
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;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;

public class OpenCV_ChangeSizeUseGassianPryamid {

    static{System.loadLibrary(Core.NATIVE_LIBRARY_NAME);}

    private JFrame frmjavaSwing;
    private Mat src = new Mat();

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

    /**
     *  Create the application.
     */
    public OpenCV_ChangeSizeUseGassianPryamid(){
        init();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void init(){
        final Mat src = Imgcodecs.imread("D:\\projects\\Java\\OpenCV_Samples\\resource\\imgs\\lena.jpg");
        setSource(src);
        BufferedImage image=matToBufferedImage(src);

        frmjavaSwing = new JFrame();
        frmjavaSwing.setTitle("opencv ���j�Y�p�m��2");
        frmjavaSwing.setBounds(100, 100, 520, 550);
        frmjavaSwing.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frmjavaSwing.getContentPane().setLayout(null);

        final JLabel lblNewLabel = new JLabel("");
        lblNewLabel.setBounds(10, 68, 438, 438);
        lblNewLabel.setIcon(new ImageIcon(image));
        frmjavaSwing.getContentPane().add(lblNewLabel);

        JButton btnNewButton = new JButton("���j2��");
        btnNewButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                BufferedImage newImage=matToBufferedImage( pyrUp(getSource()));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
        btnNewButton.setBounds(63, 21, 87, 23);
        frmjavaSwing.getContentPane().add(btnNewButton);

        JButton button = new JButton("�Y�p2��");
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                BufferedImage newImage=matToBufferedImage( pyrDown(getSource()));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
        button.setBounds(221, 21, 87, 23);
        frmjavaSwing.getContentPane().add(button);
    }

    public Mat pyrUp(Mat source){

        Mat destination=new Mat(source.rows(),source.cols(),source.type());
        Imgproc.pyrUp(source, destination, new Size(source.rows()*2,source.cols()*2));
        setSource(destination);
        return destination;

    }

    public Mat pyrDown(Mat source){

        Mat destination=new Mat(source.rows(),source.cols(),source.type());
        Imgproc.pyrDown(source, destination, new Size(source.rows()*0.5,source.cols()*0.5));
        setSource(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;
    }


    public Mat getSource() {
        return src;
    }

    public void setSource(Mat source) {
        this.src = source;
    }
}
```
<H5>Result</H5>
![opencv_scale_up_image.JPG](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/276243/155c7653-8574-9c8a-64ee-735e23f8f2f1.jpeg)
![opencv_scale_down_image.JPG](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/276243/bd39c0d7-b683-103c-235b-6d007fef9258.jpeg)