1 /** 2 * Copyright (c) 2011, The University of Southampton and the individual contributors. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without modification, 6 * are permitted provided that the following conditions are met: 7 * 8 * * Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 11 * * Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation 13 * and/or other materials provided with the distribution. 14 * 15 * * Neither the name of the University of Southampton nor the names of its 16 * contributors may be used to endorse or promote products derived from this 17 * software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 22 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR 23 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 26 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 /** 31 * 32 */ 33 package org.openimaj.video.processing.motion; 34 35 import java.util.LinkedList; 36 import java.util.Map; 37 import java.util.Queue; 38 39 import org.openimaj.image.FImage; 40 import org.openimaj.math.geometry.point.Point2d; 41 import org.openimaj.video.Video; 42 import org.openimaj.video.VideoFrame; 43 import org.openimaj.video.analyser.VideoAnalyser; 44 import org.openimaj.video.timecode.HrsMinSecFrameTimecode; 45 46 47 /** 48 * A motion estimator will estimate the motion of parts of a video frame. 49 * This class includes a set of algorithms for calculating the motion estimation. 50 * <p> 51 * This class deals with the buffering of frames from the video which to pass 52 * to the motion estimation. The class is abstract and the method 53 * {@link #estimateMotionField(MotionEstimatorAlgorithm, VideoFrame, VideoFrame[])} 54 * must be overridden by an implementing class to provide the field over which 55 * the motion estimation will take place. This field may, for example, be a grid 56 * or an overlapping grid. This overridden method must also determine the appropriate 57 * way to call the motion estimation algorithm while returning a map which maps 58 * a point to a displacement vector. 59 * 60 * @author David Dupplaw (dpd@ecs.soton.ac.uk) 61 * @created 1 Mar 2012 62 * 63 */ 64 @SuppressWarnings( "javadoc" ) 65 public abstract class MotionEstimator extends VideoAnalyser<FImage> 66 { 67 /** The estimator to use */ 68 private MotionEstimatorAlgorithm estimator = null; 69 70 /** The old frame stack. It's a queue so the oldest frame is popped off */ 71 private Queue<VideoFrame<FImage>> oldFrames = null; 72 73 /** The estimated motion vectors for the last analysed frame */ 74 public Map<Point2d,Point2d> motionVectors = null; 75 76 /** 77 * Constructor a new motion estimator using the given algorithm. 78 * @param alg The algorithm to use to estimate motion. 79 */ 80 public MotionEstimator( MotionEstimatorAlgorithm alg ) 81 { 82 this.estimator = alg; 83 oldFrames = new LinkedList<VideoFrame<FImage>>(); 84 } 85 86 /** 87 * Create a chainable motion estimator. 88 * @param v The video to chain to 89 * @param alg The algorithm to use to estimate motion 90 */ 91 public MotionEstimator( Video<FImage> v, MotionEstimatorAlgorithm alg ) 92 { 93 super(v); 94 this.estimator = alg; 95 oldFrames = new LinkedList<VideoFrame<FImage>>(); 96 } 97 98 /** 99 * {@inheritDoc} 100 * @see org.openimaj.video.analyser.VideoAnalyser#analyseFrame(org.openimaj.image.Image) 101 */ 102 @SuppressWarnings( "unchecked" ) 103 @Override 104 public void analyseFrame( FImage frame ) 105 { 106 VideoFrame<FImage> vf = new VideoFrame<FImage>( frame, 107 new HrsMinSecFrameTimecode( getTimeStamp(), getFPS() ) ); 108 109 motionVectors = estimateMotionField( estimator, vf, 110 oldFrames.toArray( new VideoFrame[0] ) ); 111 112 oldFrames.offer( vf ); 113 114 // Make sure there's never too many frames in the queue 115 if( oldFrames.size() > estimator.requiredNumberOfFrames() ) 116 oldFrames.poll(); 117 } 118 119 /** 120 * Return the estimated motion vectors for the last processed frame. 121 * @return The estimated motion vectors 122 */ 123 public Map<Point2d,Point2d> getMotionVectors() 124 { 125 return motionVectors; 126 } 127 128 /** 129 * This method needs to be overridden for specific layouts of motion 130 * field within the image. 131 * 132 * @param frame The current frame 133 * @param array The list of previous frames (based on the estimator) 134 * @return The motion field 135 */ 136 protected abstract Map<Point2d, Point2d> estimateMotionField( 137 MotionEstimatorAlgorithm estimator, VideoFrame<FImage> frame, 138 VideoFrame<FImage>[] array ); 139 }