Desktop : OpenCV Erode

<h5>Goal</h5>
Test OpenCV Erode.

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

public class OpenCV_Erode {
    static {System.loadLibrary(Core.NATIVE_LIBRARY_NAME);}
    private JFrame frmjavaSwing;
    double alpha =2;
    double beta = 50;

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

    /**
     * Create the application.
     */
    public OpenCV_Erode() {
        initialize();
        System.out.println("Imgproc.MORPH_RECT="+Imgproc.MORPH_RECT);
        System.out.println("Imgproc.MORPH_ELLIPSE="+ Imgproc.MORPH_ELLIPSE);
        System.out.println("Imgproc.MORPH_CROSS="+Imgproc.MORPH_CROSS);

    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        final Mat source = Imgcodecs.imread("D:\\projects\\Java\\OpenCV_Samples\\resource\\imgs\\lena.jpg");

        BufferedImage image=matToBufferedImage(source);

        frmjavaSwing = new JFrame();
        frmjavaSwing.setTitle("opencv Erode(»G»k)³B²z½m²ß");
        frmjavaSwing.setBounds(100, 100, 520, 550);
        frmjavaSwing.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frmjavaSwing.getContentPane().setLayout(null);

        final JLabel showKsizeValue = new JLabel("0");
        showKsizeValue.setBounds(250, 10, 46, 15);
        frmjavaSwing.getContentPane().add(showKsizeValue);

        final JLabel showShapeValue = new JLabel("0");
        showShapeValue.setBounds(402, 10, 46, 15);
        frmjavaSwing.getContentPane().add(showShapeValue);

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

        final JSlider slider_shape = new JSlider();
        slider_shape.setValue(0);
        slider_shape.setMaximum(2);
        slider_shape.setBounds(326, 10, 75, 25);
        frmjavaSwing.getContentPane().add(slider_shape);

        final JSlider slider_ksize = new JSlider();
        slider_ksize.setMaximum(50);
        slider_ksize.setValue(0);
        slider_ksize.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                //System.out.println(slider_alpha.getValue());
                showKsizeValue.setText(slider_ksize.getValue()+"");
                BufferedImage newImage=matToBufferedImage(erode(source,slider_ksize.getValue(),slider_shape.getValue()));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
        slider_ksize.setBounds(47, 10, 200, 25);
        frmjavaSwing.getContentPane().add(slider_ksize);

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

        JLabel lblBeta = new JLabel("shape");
        lblBeta.setBounds(283, 10, 46, 15);
        frmjavaSwing.getContentPane().add(lblBeta);


        slider_shape.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                showShapeValue.setText(slider_shape.getValue()+"");
                BufferedImage newImage=matToBufferedImage(erode(source,slider_ksize.getValue(),slider_shape.getValue()));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
    }
    public Mat erode(Mat source,int ksize,int shape){

        Mat destination=new Mat(source.rows(),source.cols(),source.type());
        Mat element = Imgproc.getStructuringElement(shape,new Size(2*ksize + 1, 2*ksize+1));
        Imgproc.erode(source, destination, element);

        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_erode.JPG](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/276243/5af285ed-a6a2-c1e8-34ca-8f1e2b875b68.jpeg)