Desktop : OpenCV_BoxFilterBlur

<h5>Goal</h5>
Test OpenCV box filter.

```OpenCV_BoxFilterBlur.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_BoxFilterBlur {

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

    private JFrame frmjavaSwing;

    int apertureLinearSize =1; //follow API,must be positive and odd
    /**
     * Launch the application.
     */
    public static void main(String[] args) {

        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    OpenCV_BoxFilterBlur window = new OpenCV_BoxFilterBlur();
                    window.frmjavaSwing.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
    /**
     * Create the application.
     */
    public OpenCV_BoxFilterBlur() {
        initialize();
    }

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

        BufferedImage image=matToBufferedImage(BlurFilter(source,apertureLinearSize));

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

        final JLabel showKsizeValue = new JLabel("1");
        showKsizeValue.setBounds(372, 10, 46, 15);
        frmjavaSwing.getContentPane().add(showKsizeValue);

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

        final JSlider slider_X = new JSlider();
        slider_X.setMaximum(203);
        slider_X.setMinimum(1);
        slider_X.setValue(1);
        slider_X.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent arg0) {
                showKsizeValue.setText(slider_X.getValue()+"");
                BufferedImage newImage=matToBufferedImage(BlurFilter(source,slider_X.getValue()));
                lblNewLabel.setIcon(new ImageIcon(newImage));
            }
        });
        slider_X.setBounds(164, 10, 200, 25);
        frmjavaSwing.getContentPane().add(slider_X);

        JLabel lblAlpha = new JLabel("Ksize");
        lblAlpha.setBounds(116, 10, 38, 15);
        frmjavaSwing.getContentPane().add(lblAlpha);

    }
    public Mat BlurFilter(Mat source,int KSize){

        Mat destination=new Mat(source.rows(),source.cols(),source.type());
        Imgproc.boxFilter(source, destination,-1, new Size(KSize,KSize));
        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_box_filter.JPG](https://qiita-image-store.s3.ap-northeast-1.amazonaws.com/0/276243/dbb7b96a-39ed-101f-f56a-ba3995377abe.jpeg)