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 package org.openimaj.video.processing.tracking;
31
32 import java.util.ArrayList;
33 import java.util.List;
34
35 import org.openimaj.image.FImage;
36 import org.openimaj.math.geometry.shape.Rectangle;
37 import org.openimaj.video.tracking.klt.FeatureList;
38 import org.openimaj.video.tracking.klt.KLTTracker;
39 import org.openimaj.video.tracking.klt.TrackingContext;
40
41 /**
42 * A tracker that will track one rectangular region using the KLTTracker.
43 *
44 * @author David Dupplaw (dpd@ecs.soton.ac.uk)
45 *
46 * @created 13 Oct 2011
47 */
48 public class BasicObjectTracker implements ObjectTracker<Rectangle,FImage>
49 {
50 /** The tracking context for the KLTTracker */
51 private TrackingContext trackingContext = new TrackingContext();
52
53 /** The feature list used for the tracking */
54 private FeatureList featureList = null;
55
56 /** The number of features found during the initialisation stage of the tracking */
57 private int featuresFound = -1;
58
59 /** The tracker used to track the faces */
60 private KLTTracker tracker = null;
61
62 /** The accuracy to use when tracking, between 0 and 1 */
63 private double accuracy = 0.5;
64
65 /** The previous frame */
66 private FImage previousFrame;
67
68 /**
69 * Default constructor that will use 50 features and an accuracy of 0.5.
70 */
71 public BasicObjectTracker()
72 {
73 this( 50, 0.5 );
74 }
75
76 /**
77 * Default constructor that takes the number of features to be used.
78 * Will use an accuracy of 0.5.
79 *
80 * @param nFeatures The number of features to use.
81 */
82 public BasicObjectTracker( int nFeatures )
83 {
84 this( nFeatures, 0.5 );
85 }
86
87 /**
88 * Constructor that takes the accuracy to use for tracking. Will use 50
89 * features.
90 *
91 * @param accuracy The accuracy to use.
92 */
93 public BasicObjectTracker( double accuracy )
94 {
95 this( 50, accuracy );
96 }
97
98 /**
99 * Constructor that takes the number of features to use and the accuracy
100 * for tracking.
101 *
102 * @param nFeatures The number of features to use.
103 * @param accuracy The accuracy to use
104 */
105 public BasicObjectTracker( int nFeatures, double accuracy )
106 {
107 this.featureList = new FeatureList( nFeatures );
108 this.accuracy = accuracy;
109 tracker = new KLTTracker( trackingContext, featureList );
110 }
111
112 /**
113 * Reset this tracker using the given image
114 * @return TRUE if the tracking continued ok; FALSE otherwise
115 */
116 @Override
117 public List<Rectangle> trackObject( FImage img )
118 {
119 List<Rectangle> trackedObjects = new ArrayList<Rectangle>();
120
121 tracker.trackFeatures( previousFrame, img );
122
123 // If we're losing features left-right and centre then we say
124 // we've lost the object we're tracking
125 if( featureList.countRemainingFeatures() <= featuresFound * accuracy )
126 return trackedObjects;
127
128 trackedObjects.add( featureList.getBounds() );
129
130 previousFrame = img;
131
132 return trackedObjects;
133 }
134
135 /**
136 * Initialise this tracker with a particular area on a particular
137 * image.
138 *
139 * @param bounds The area to track
140 * @param img The image
141 */
142 @Override
143 public List<Rectangle> initialiseTracking( Rectangle bounds, FImage img )
144 {
145 List<Rectangle> initialObjects = new ArrayList<Rectangle>();
146
147 // Set the tracking area to be the face found
148 trackingContext.setTargetArea( bounds );
149
150 // Select the good features from the area
151 tracker.selectGoodFeatures( img );
152
153 // Remember how many features we found, so that if we
154 // start to lose them, we can re-initialise the tracking
155 featuresFound = featureList.countRemainingFeatures();
156
157 // Add the initial bounds as the found object
158 initialObjects.add( bounds );
159
160 previousFrame = img;
161
162 return initialObjects;
163 }
164
165 /**
166 * Returns the list of features that the tracker has been tracking.
167 * @return the {@link FeatureList}
168 */
169 public FeatureList getFeatureList()
170 {
171 return featureList;
172 }
173 }