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.feature.DoubleFV;
033import org.openimaj.feature.FeatureVectorProvider;
034import org.openimaj.image.FImage;
035import org.openimaj.image.analyser.ImageAnalyser;
036
037/**
038 * Produce a feature vector that describes the average intensity
039 * distribution across the from left to right. 
040 * 
041 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
042 *
043 */
044public class HorizontalIntensityDistribution implements ImageAnalyser<FImage>, FeatureVectorProvider<DoubleFV> {
045        DoubleFV fv;
046        int nbins = 10;
047        
048        /**
049         * Construct the {@link HorizontalIntensityDistribution} feature
050         * extractor using the default of 10 equally spaced bins.
051         */
052        public HorizontalIntensityDistribution() {
053        }
054        
055        /**
056         * Construct the {@link HorizontalIntensityDistribution} feature
057         * extractor using the given number of equally spaced bins.
058         * @param nbins number of bins to split the image into
059         */
060        public HorizontalIntensityDistribution(int nbins) {
061                this.nbins = nbins;
062        }
063        
064        @Override
065        public DoubleFV getFeatureVector() {
066                return fv;
067        }
068
069        /* (non-Javadoc)
070         * @see org.openimaj.image.analyser.ImageAnalyser#analyseImage(org.openimaj.image.Image)
071         */
072        @Override
073        public void analyseImage(FImage image) {
074                fv = new DoubleFV(nbins);
075                int [] counts = new int [nbins]; 
076                
077                float stripWidth = (float)image.width / (float)nbins;
078                for (int y=0; y<image.height; y++) {
079                        for (int x=0; x<image.width; x++) {
080                                int bin = (int)(x / stripWidth);
081                                
082                                fv.values[bin] += image.pixels[y][x];
083                                counts[bin]++;
084                        }
085                }
086                
087                for (int i=0; i<nbins; i++)
088                        fv.values[i] /= counts[i];
089        }
090}
091