如何在视频中选择矩形ROI - OpenCV java

Question

我正在尝试对通道进行预处理，以便我可以在之后使用通道检测。 所以我想选择一个带OpenCV的矩形ROI，但它只给我下面的裁剪Rect。我不知道如何将Rect复制到原始图像或者应该做什么。

我想在原始图像上使用我的Rect ROI，如下图所示。 非常感谢帮助，因为在互联网上没有太多的java支持

import org.opencv.core.*;
import org.opencv.videoio.*;

import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.util.concurrent.TimeUnit;

import javax.swing.*;

public class PreProcessing {



public static void main(String[] args) throws InterruptedException
{
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);

//Create new MAT object
Mat frame = new Mat();

//Create new VideoCapture object
VideoCapture camera = new VideoCapture("Car Clip NA.mov");

//Create new JFrame object
JFrame jframe = new JFrame();

//Inform jframe what to do in the event that you close the program
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

//Create a new JLabel object vidpanel
JLabel vidPanel = new JLabel();

//assign vidPanel to jframe
jframe.setContentPane(vidPanel);

//set frame size
jframe.setSize(640, 360);

//make jframe visible
jframe.setVisible(true);
while (true) {
    //If next video frame is available
    if (camera.read(frame)) {
        /Create new image icon object and convert Mat to Buffered Image
        Rect roi = new Rect(0, 200, 640, 140);
        Mat rectCrop = frame.submat(roi);
        //Mat imageROI = new Mat(frame,roi);
        Mat bw = new Mat();
        Mat destination = new Mat();
        Imgproc.GaussianBlur(rectCrop,destination ,new Size(9,9),0);
        Imgproc.cvtColor(destination, bw, Imgproc.COLOR_RGBA2GRAY);


        //bw.copyTo(rectCrop);
        ImageIcon image = new ImageIcon(Mat2BufferedImage(bw));

        Thread.sleep(20);
        //Update the image in the vidPanel
        vidPanel.setIcon(image);
        //Update the vidPanel in the JFrame
        vidPanel.repaint();

    }
}
}

public static BufferedImage Mat2BufferedImage(Mat m) {
//Method converts a Mat to a Buffered Image
int type = BufferedImage.TYPE_BYTE_GRAY;
 if ( m.channels() > 1 ) {
     type = BufferedImage.TYPE_3BYTE_BGR;
 }
 int bufferSize = m.channels()*m.cols()*m.rows();
 byte [] b = new byte[bufferSize];
 m.get(0,0,b); // get all the pixels
 BufferedImage image = new BufferedImage(m.cols(),m.rows(), type);
 final byte[] targetPixels = ((DataBufferByte) 
 image.getRaster().getDataBuffer()).getData();
 System.arraycopy(b, 0, targetPixels, 0, b.length);  
 return image;
 }

}