Example usage for org.opencv.videoio VideoCapture grab

Introduction

In this page you can find the example usage for org.opencv.videoio VideoCapture grab.

Prototype

public boolean grab() 

Source Link

Usage

From source file:templatematching.ProcessFrame.java

public Image processFrame(VideoCapture capture) {

    while (k < 2) {
        capture.grab();
        capture.retrieve(frame);/*  www .j a va  2s.c om*/
        capture.retrieve(frame);
        //treat each frame of the capture individually
        // retives the grabbed frame into Mat obj
        int frame_width = frame.rows();
        int frame_height = frame.cols();
        MatOfRect faces1 = new MatOfRect();
        Mat frame_gray = new Mat();
        Mat ImageROI;
        //change the frame to gray-scale
        Imgproc.cvtColor(frame, frame_gray, Imgproc.COLOR_BGR2GRAY);//gray scale conversion
        //use histogram equilization
        //Imgproc.equalizeHist(frame_gray, frame_gray );
        //use the face classifie
        faceHaar.detectMultiScale(frame_gray, faces1, 1.1, 2, 2, new Size(30, 30), new Size());
        Rect[] faces = faces1.toArray();

        for (int i = 0; i < faces.length; i++) {
            //  System.out.println("Processing faces");
            Point center = new Point(faces[i].x + faces[i].width * 0.5, faces[i].y + faces[i].height * 0.5);
            Imgproc.ellipse(frame, center, new Size(faces[i].width * 0.5, faces[i].height * 0.5), 0, 0, 360,
                    new Scalar(0, 0, 255), 4, 8, 0);
            Mat faceROI = frame_gray.submat(faces[i]);

            MatOfRect eyes1 = new MatOfRect();
            eyesHaar.detectMultiScale(faceROI, eyes1, 1.15, 2, 2, new Size(30, 30), new Size());
            //eyesHaar.detectMultiScale(faceROI, eyes1, 1.1, 2,  Objdetect.CASCADE_FIND_BIGGEST_OBJECT|Objdetect.CASCADE_SCALE_IMAGE, new Size(30,30),new Size());
            Rect[] eyes = eyes1.toArray();
            //  System.out.println("Processing eyes");
            for (int j = 0; j < eyes.length; j++) {

                Mat eyeROI = frame_gray.submat(eyes[i]);
                Point center1 = new Point(faces[i].x + eyes[j].x + eyes[j].width * 0.5,
                        faces[i].y + eyes[j].y + eyes[j].height * 0.5);
                int radius = (int) ((eyes[j].width + eyes[j].height) * 0.005);
                Imgproc.circle(frame, center1, radius, new Scalar(255, 0, 0), 4, 8, 0);
                Pupilx = (int) center1.x;
                Pupily = (int) center1.y;
                ROIwidth = eyes[j].width;
                ROIheight = eyes[j].height;
                Point centerX[] = new Point[2];
                centerX[k] = center1;
                //performing the scaling of the coordintaes to fir to the screen dimensions
                if (k == 0) {
                    scaledPupilx = Pupilx;
                    scaledPupily = Pupily;
                    k++;
                } else {
                    System.out.println("In else part");
                    deltax = (int) Math.abs((centerX[k].x - centerX[k - 1].x));
                    deltay = (int) Math.abs((centerX[k].y - centerX[k - 1].y));

                    scaled_deltax = (deltax * (65535 / ROIwidth));

                    scaled_deltay = (deltay * (65535 / ROIheight));
                    scaledPupilx = centerX[k - 1].x + scaled_deltax;

                    scaledPupily = centerX[k - 1].y + scaled_deltay;
                }
                if (k == 2)
                    k = 0;
                //set the cursor position to the scaled coordinates
                try {
                    Robot robot = new Robot();

                    robot.mouseMove((int) (1366 - scaledPupilx), (int) (768 - scaledPupily));
                } catch (AWTException ex) {

                }
            }
            //define a window for displaying the frame

            //release window if any key is hit

        }

        MatOfByte mem = new MatOfByte();
        Imgcodecs.imencode(".bmp", frame, mem);
        Image im = null;
        try {
            im = ImageIO.read(new ByteArrayInputStream(mem.toArray()));

        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return im;
    }
    return null;

}

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