Desktop : OpenCV Edge Preserving Filter

<h5>Goal</h5>
Test OpenCV edge preserving filter.

```OpenCV_EdgePreservingFilter.java
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.photo.Photo;

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

public class OpenCV_EdgePreservingFilter {
    static{ System.loadLibrary(Core.NATIVE_LIBRARY_NAME); }
    private JFrame frmjavaSwing;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {

        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    OpenCV_EdgePreservingFilter window = new OpenCV_EdgePreservingFilter();
                    window.frmjavaSwing.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
    /**
     * Create the application.
     */
    public OpenCV_EdgePreservingFilter() {
        initialize();
        System.out.println("Photo.RECURS_FILTER="+Photo.RECURS_FILTER);
        System.out.println("Photo.NORMCONV_FILTER ="+ Photo.NORMCONV_FILTER);

    }

    /**
     * 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 edgePreservingFilter處理練習");
        frmjavaSwing.setBounds(100, 100, 520, 550);
        frmjavaSwing.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frmjavaSwing.getContentPane().setLayout(null);

        final JLabel showFlagsValue = new JLabel("1");
        showFlagsValue.setBounds(84, 32, 46, 15);
        frmjavaSwing.getContentPane().add(showFlagsValue);

        final JLabel showSigmaSValue = new JLabel("1");
        showSigmaSValue.setBounds(256, 32, 46, 15);
        frmjavaSwing.getContentPane().add(showSigmaSValue);

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

        final JSlider slider_sigmaS = new JSlider();
        slider_sigmaS.setMinimum(1);
        slider_sigmaS.setValue(1);
        slider_sigmaS.setMaximum(500);
        slider_sigmaS.setBounds(220, 10, 75, 25);
        frmjavaSwing.getContentPane().add(slider_sigmaS);

        final JSlider slider_flags = new JSlider();
        slider_flags.setMinimum(1);
        slider_flags.setMaximum(2);
        slider_flags.setValue(1);

        slider_flags.setBounds(57, 10, 86, 25);
        frmjavaSwing.getContentPane().add(slider_flags);

        JLabel lblAlpha = new JLabel("flags");
        lblAlpha.setBounds(10, 10, 56, 15);
        frmjavaSwing.getContentPane().add(lblAlpha);

        JLabel lblsigma_s = new JLabel("sigma_s");
        lblsigma_s.setBounds(155, 10, 67, 15);
        frmjavaSwing.getContentPane().add(lblsigma_s);

        JLabel lblNewLabel_1 = new JLabel("sigma_r");
        lblNewLabel_1.setBounds(315, 10, 85, 15);
        frmjavaSwing.getContentPane().add(lblNewLabel_1);

        final JSlider slider_sigmaR = new JSlider();

        slider_sigmaR.setValue(1);
        slider_sigmaR.setMinimum(1);
        slider_sigmaR.setMaximum(20);
        slider_sigmaR.setBounds(373, 8, 75, 25);
        frmjavaSwing.getContentPane().add(slider_sigmaR);

        final JLabel showSigmaRValue = new JLabel("1");
        showSigmaRValue.setBounds(417, 32, 46, 15);
        frmjavaSwing.getContentPane().add(showSigmaRValue);

        slider_sigmaR.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                showSigmaRValue.setText((float)slider_sigmaR.getValue()/10+"");
                BufferedImage newImage=matToBufferedImage(EdgePreservingFilter(slider_flags.getValue(),slider_sigmaS.getValue(),(float)slider_sigmaR.getValue()/10));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
        slider_flags.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                //System.out.println(slider_alpha.getValue());
                showFlagsValue.setText(slider_flags.getValue()+"");
                BufferedImage newImage=matToBufferedImage(EdgePreservingFilter(slider_flags.getValue(),slider_sigmaS.getValue(),(float)slider_sigmaR.getValue()/10));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });

        slider_sigmaS.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                showSigmaSValue.setText(slider_sigmaS.getValue()+"");
                BufferedImage newImage=matToBufferedImage(EdgePreservingFilter(slider_flags.getValue(),slider_sigmaS.getValue(),(float)slider_sigmaR.getValue()/10));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
    }
    public Mat EdgePreservingFilter(int flags,float sigma_s ,float sigma_r ){
        Mat src = Imgcodecs.imread("D:\\projects\\Java\\OpenCV_Samples\\resource\\imgs\\lena.jpg",Imgcodecs.CV_LOAD_IMAGE_COLOR);
        Mat destination=new Mat();
        Photo.edgePreservingFilter(src, destination, flags, sigma_s, sigma_r);
        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_edge_preserving_filter.JPG](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/276243/f51f1286-6c80-c03f-f252-d3a0ab5bb825.jpeg)