001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.demos.servotrack;
031
032import java.util.List;
033
034import org.openimaj.image.FImage;
035import org.openimaj.image.MBFImage;
036import org.openimaj.image.colour.RGBColour;
037import org.openimaj.image.connectedcomponent.ConnectedComponentLabeler;
038import org.openimaj.image.pixel.ConnectedComponent;
039import org.openimaj.image.pixel.ConnectedComponent.ConnectMode;
040import org.openimaj.math.geometry.point.Point2d;
041import org.openimaj.math.geometry.point.Point2dImpl;
042import org.openimaj.video.VideoDisplay;
043import org.openimaj.video.VideoDisplayListener;
044import org.openimaj.video.capture.VideoCapture;
045
046public class FrameDiffTrack {
047        public static void main(String[] args) throws Exception {
048                final VideoCapture capture = new VideoCapture(640, 480, VideoCapture.getVideoDevices().get(0));
049                final PTServoController servos = new PTServoController("/dev/tty.usbmodemfa131");
050                final Point2d frameCentre = new Point2dImpl(capture.getWidth() / 2, capture.getHeight() / 2);
051
052                VideoDisplay.createVideoDisplay(capture).addVideoListener(new VideoDisplayListener<MBFImage>() {
053                        FImage previousFrame = capture.getCurrentFrame().flatten();
054                        int inhibit = 0;
055
056                        @Override
057                        public void beforeUpdate(MBFImage frame) {
058                                final FImage thisFrame = frame.flatten();
059                                final FImage delta = thisFrame.subtract(previousFrame).abs().threshold(0.3f);
060
061                                final ConnectedComponentLabeler ccl = new ConnectedComponentLabeler(ConnectMode.CONNECT_8);
062                                final List<ConnectedComponent> comps = ccl.findComponents(delta);
063
064                                if (inhibit <= 0 && comps.size() > 0) {
065                                        ConnectedComponent big = comps.get(0);
066
067                                        for (int i = 1; i < comps.size(); i++) {
068                                                final ConnectedComponent cc = comps.get(i);
069                                                if (cc.calculateArea() > big.calculateArea())
070                                                        big = cc;
071                                        }
072
073                                        if (big.calculateArea() > 500) {
074                                                frame.drawShape(big.toPolygon(), RGBColour.RED);
075
076                                                final Point2d pt = big.calculateCentroidPixel();
077
078                                                final Point2d deltap = pt.minus(frameCentre);
079
080                                                final double damp = 0.03;
081
082                                                if (deltap.getX() < 0) {
083                                                        servos.changePanBy(-(int) (damp * deltap.getX()));
084                                                } else if (deltap.getX() > 0) {
085                                                        servos.changePanBy(-(int) (damp * deltap.getX()));
086                                                }
087
088                                                if (deltap.getY() < 0) {
089                                                        servos.changeTiltBy((int) (damp * deltap.getY()));
090                                                } else if (deltap.getY() > 0) {
091                                                        servos.changeTiltBy((int) (damp * deltap.getY()));
092                                                }
093
094                                                inhibit = 10;
095                                        }
096                                }
097
098                                previousFrame = thisFrame;
099                                inhibit--;
100                        }
101
102                        @Override
103                        public void afterUpdate(VideoDisplay<MBFImage> display) {
104                                // do nothing
105                        }
106                });
107
108        }
109}