MotionDetector.java

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package rlpark.plugin.opencv.samples;

/* 
 * I developed some code for recognize motion detections with JavaCV.
 * Actually, it works with an array of Rect, performing, every cicle, an
 * intersection test with area of difference with the rect of interests
 * (this array is callad "sa", stands for SizedArea). I hope could this
 * helps someone.
 * 
 * Feel free to ask about any question regarding the code above, cheers!
 *
 * Angelo Marchesin <marchesin.angelo@gmail.com>
 */

import static com.googlecode.javacv.cpp.opencv_core.IPL_DEPTH_8U;
import static com.googlecode.javacv.cpp.opencv_core.cvAbsDiff;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_GAUSSIAN;
import static com.googlecode.javacv.cpp.opencv_imgproc.CV_RGB2GRAY;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvCvtColor;
import static com.googlecode.javacv.cpp.opencv_imgproc.cvSmooth;

import com.googlecode.javacv.CanvasFrame;
import com.googlecode.javacv.OpenCVFrameGrabber;
import com.googlecode.javacv.cpp.opencv_core.IplImage;

public class MotionDetector {
    public static void main(String[] args) throws Exception {
        OpenCVFrameGrabber grabber = new OpenCVFrameGrabber(0);
        grabber.start();

        IplImage frame = grabber.grab();
        IplImage image = null;
        IplImage prevImage = null;
        IplImage diff = null;

        CanvasFrame canvasFrame = new CanvasFrame("Some Title");
        canvasFrame.setCanvasSize(frame.width(), frame.height());

        while (canvasFrame.isVisible() && (frame = grabber.grab()) != null) {
            cvSmooth(frame, frame, CV_GAUSSIAN, 9, 9, 2, 2);
            if (image == null) {
                image = IplImage.create(frame.width(), frame.height(), IPL_DEPTH_8U, 1);
                cvCvtColor(frame, image, CV_RGB2GRAY);
            } else {
                prevImage = IplImage.create(frame.width(), frame.height(), IPL_DEPTH_8U, 1);
                prevImage = image;
                image = IplImage.create(frame.width(), frame.height(), IPL_DEPTH_8U, 1);
                cvCvtColor(frame, image, CV_RGB2GRAY);
            }

            if (diff == null) {
                diff = IplImage.create(frame.width(), frame.height(), IPL_DEPTH_8U, 1);
            }

            if (prevImage != null) {
                // perform ABS difference
                cvAbsDiff(image, prevImage, diff);
                // do some threshold for wipe away useless details
                // cvThreshold(diff, diff, 64, 255, CV_THRESH_BINARY);
                canvasFrame.showImage(diff);
            }
        }
        grabber.stop();
        canvasFrame.dispose();
    }
}