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.image.processing.face.feature.comparison;
031
032import java.io.DataInput;
033import java.io.DataOutput;
034import java.io.IOException;
035import java.util.List;
036
037import org.openimaj.citation.annotation.Reference;
038import org.openimaj.citation.annotation.ReferenceType;
039import org.openimaj.image.FImage;
040import org.openimaj.image.pixel.Pixel;
041import org.openimaj.image.processing.face.feature.ltp.LtpDtFeature;
042
043/**
044 * A comparator for Local Trinary Pattern Features using a
045 * Euclidean distance transform.
046 * 
047 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
048 */
049@Reference(
050                type = ReferenceType.Article,
051                author = { "Tan, Xiaoyang", "Triggs, Bill" },
052                title = "Enhanced local texture feature sets for face recognition under difficult lighting conditions",
053                year = "2010",
054                journal = "Trans. Img. Proc.",
055                pages = { "1635", "1650" },
056                url = "http://dx.doi.org/10.1109/TIP.2010.2042645",
057                month = "June",
058                number = "6",
059                publisher = "IEEE Press",
060                volume = "19"
061        )
062public class LtpDtFeatureComparator implements FacialFeatureComparator<LtpDtFeature> {
063
064        @Override
065        public double compare(LtpDtFeature query, LtpDtFeature target) {
066                List<List<Pixel>> slicePixels = query.ltpPixels;
067                float distance = 0;
068                
069                FImage[] distanceMaps = target.getDistanceMaps();
070                
071                for (int i=0; i<distanceMaps.length; i++) {
072                        List<Pixel> pixels = slicePixels.get(i);
073                        
074                        if (distanceMaps[i] == null || pixels == null)
075                                continue;
076                        
077                        for (Pixel p : pixels) {
078                                distance += distanceMaps[i].pixels[p.y][p.x];
079                        }
080                }
081                
082                return distance;
083        }
084
085        @Override
086        public boolean isDistance() {
087                return true;
088        }
089
090        @Override
091        public void readBinary(DataInput in) throws IOException {
092                //do nothing
093        }
094
095        @Override
096        public byte[] binaryHeader() {
097                //do nothing
098                return null;
099        }
100
101        @Override
102        public void writeBinary(DataOutput out) throws IOException {
103                //do nothing
104        }
105        
106        @Override
107        public String toString() {
108                return "LtpDtFeatureComparator";
109        }
110}