BlendApp.java

import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.InputStream;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfByte;
import org.opencv.core.Rect;
import org.opencv.core.Size;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.opencv.videoio.VideoCapture;

 
public class BlendApp {
    public static void main(String[] args) {
        System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
        
        VideoCapture capL = new VideoCapture(1);
        VideoCapture capR = new VideoCapture(3);
        
        if (!capL.isOpened() || !capR.isOpened()) {
        	System.out.println("ERROR: can not open video device");
        	System.exit(-1);
        }
       
        while(true) {
        	Mat cameraFrameL = new Mat();
        	Mat cameraFrameR = new Mat();
        	capL.read(cameraFrameL);
        	capR.read(cameraFrameR);
        	Mat combined = new Mat(cameraFrameL.rows() + cameraFrameR.rows(), cameraFrameL.cols(), cameraFrameL.type());
        	cameraFrameL.copyTo(combined.submat(new Rect(0, 0, cameraFrameL.cols(), cameraFrameL.rows())));
        	cameraFrameR.copyTo(combined.submat(new Rect(0, cameraFrameL.rows(), cameraFrameR.cols(), cameraFrameR.rows())));
        	showResult(combined);
        }
    }
    
    static JFrame frame = null;
    static JLabel label = null;

    public static void showResult(Mat img) {
        Imgproc.resize(img, img, new Size(1280, 1440));
        MatOfByte matOfByte = new MatOfByte();
        Imgcodecs.imencode(".jpg", img, matOfByte);
        byte[] byteArray = matOfByte.toArray();
        BufferedImage bufImage = null;
        try {
            InputStream in = new ByteArrayInputStream(byteArray);
            bufImage = ImageIO.read(in);
        	if (frame == null) {
        		frame = new JFrame();
        		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Already there
        	    //frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
        	    frame.setUndecorated(true);
        		label = new JLabel(new ImageIcon(bufImage));
                frame.getContentPane().add(label);
                frame.pack();
                frame.setVisible(true);
        	}
        	else {
        		label.setIcon(new ImageIcon(bufImage));
        	}
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}