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.feature.global;
031
032import org.openimaj.citation.annotation.Reference;
033import org.openimaj.citation.annotation.ReferenceType;
034import org.openimaj.feature.DoubleFV;
035import org.openimaj.feature.DoubleFVComparison;
036import org.openimaj.feature.FeatureVectorProvider;
037import org.openimaj.image.FImage;
038import org.openimaj.image.analyser.ImageAnalyser;
039import org.openimaj.image.pixel.statistics.BlockHistogramModel;
040import org.openimaj.math.statistics.distribution.MultidimensionalHistogram;
041
042/**
043 * Implementation of the intensity balance algorithm described by Yeh et al.
044 * <p>
045 * The intensity balance measures how different the intensity is on the left
046 * side of the image compared to the right. A balance of zero means exactly
047 * balanced. Higher values are produced for more unbalanced images.
048 * 
049 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
050 */
051@Reference(
052                type = ReferenceType.Inproceedings,
053                author = { "Che-Hua Yeh", "Yuan-Chen Ho", "Brian A. Barsky", "Ming Ouhyoung" },
054                title = "Personalized Photograph Ranking and Selection System",
055                year = "2010",
056                booktitle = "Proceedings of ACM Multimedia",
057                pages = { "211", "220" },
058                month = "October",
059                customData = { "location", "Florence, Italy" })
060public class LRIntensityBalance implements ImageAnalyser<FImage>, FeatureVectorProvider<DoubleFV> {
061        int nbins = 64;
062        double balance;
063
064        /**
065         * Construct with the default 64 intensity histogram bins.
066         */
067        public LRIntensityBalance() {
068        }
069
070        /**
071         * Construct with the given number of intensity histogram bins.
072         * 
073         * @param nbins
074         *            number of intensity histogram bins
075         */
076        public LRIntensityBalance(int nbins) {
077                this.nbins = nbins;
078        }
079
080        @Override
081        public DoubleFV getFeatureVector() {
082                return new DoubleFV(new double[] { balance });
083        }
084
085        /*
086         * (non-Javadoc)
087         * 
088         * @see
089         * org.openimaj.image.analyser.ImageAnalyser#analyseImage(org.openimaj.image
090         * .Image)
091         */
092        @Override
093        public void analyseImage(FImage image) {
094                final BlockHistogramModel hm = new BlockHistogramModel(2, 1, nbins);
095
096                hm.estimateModel(image);
097
098                final MultidimensionalHistogram left = hm.histograms[0][0];
099                final MultidimensionalHistogram right = hm.histograms[0][1];
100
101                balance = left.compare(right, DoubleFVComparison.CHI_SQUARE);
102        }
103}