Example Tracker Object

• 

  Last frame from a sequence where the book was tracked using the ciruclant tracker.

In this example several different trackers can be used to track the object in the video. All of the trackers in this example use texture information (see mean-shift example for color based trackers) to localize and track the object. No one single tracker can track all the video sequences provided with BoofCV or in general. You should try out all the different video sequences and see which trackers work best when.

Example Code:

• ExampleTrackerObjectQuad.java

Concepts:

• Object tracking
• Local trackers
• Re-detection

Relevant Applets:

• Object Tracking

Example Code

/**
 * Demonstration on how to use the high level {@link TrackerObjectQuad} interface for tracking objects in a
 * video sequence.  This interface allows the target to be specified using an arbitrary quadrilateral.  Specific
 * implementations might not support that shape, so they instead will track an approximation of it.  The
 * interface also allows information on target visibility to be returned.  As is usually the case, tracker
 * specific information is lost in the high level interface and you should consider using the trackers
 * directly if more control is needed.
 *
 * This is an active area of research and all of the trackers eventually diverge given a long enough sequence.
 *
 * @author Peter Abeles
 */
public class ExampleTrackerObjectQuad {

	public static void main(String[] args) {
		MediaManager media = DefaultMediaManager.INSTANCE;
		String fileName = "../data/applet/tracking/wildcat_robot.mjpeg";

		// Create the tracker.  Comment/Uncomment to change the tracker.
		TrackerObjectQuad tracker =
				FactoryTrackerObjectQuad.circulant(null, ImageUInt8.class);
//				FactoryTrackerObjectQuad.sparseFlow(null,ImageUInt8.class,null);
//				FactoryTrackerObjectQuad.tld(null,ImageUInt8.class);
//				FactoryTrackerObjectQuad.meanShiftComaniciu2003(new ConfigComaniciu2003(), ImageType.ms(3, ImageUInt8.class));
//				FactoryTrackerObjectQuad.meanShiftComaniciu2003(new ConfigComaniciu2003(true),ImageType.ms(3,ImageUInt8.class));

				// Mean-shift likelihood will fail in this video, but is excellent at tracking objects with
				// a single unique color.  See ExampleTrackerMeanShiftLikelihood
//				FactoryTrackerObjectQuad.meanShiftLikelihood(30,5,255, MeanShiftLikelihoodType.HISTOGRAM,ImageType.ms(3,ImageUInt8.class));

		SimpleImageSequence video = media.openVideo(fileName, tracker.getImageType());

		// specify the target's initial location and initialize with the first frame
		Quadrilateral_F64 location = new Quadrilateral_F64(211.0,162.0,326.0,153.0,335.0,258.0,215.0,249.0);
		ImageBase frame = video.next();
		tracker.initialize(frame,location);

		// For displaying the results
		TrackerObjectQuadPanel gui = new TrackerObjectQuadPanel(null);
		gui.setPreferredSize(new Dimension(frame.getWidth(),frame.getHeight()));
		gui.setBackGround((BufferedImage)video.getGuiImage());
		gui.setTarget(location,true);
		ShowImages.showWindow(gui,"Tracking Results", true);

		// Track the object across each video frame and display the results
		long previous = 0;
		while( video.hasNext() ) {
			frame = video.next();

			boolean visible = tracker.process(frame,location);

			gui.setBackGround((BufferedImage) video.getGuiImage());
			gui.setTarget(location, visible);
			gui.repaint();

			// shoot for a specific frame rate
			long time = System.currentTimeMillis();
			BoofMiscOps.pause(Math.max(0,80-(time-previous)));
			previous = time;
		}
	}
}