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.FeatureVectorProvider;
036import org.openimaj.image.FImage;
037import org.openimaj.image.analyser.ImageAnalyser;
038import org.openimaj.image.mask.AbstractMaskedObject;
039import org.openimaj.image.processing.convolution.AverageBoxFilter;
040import org.openimaj.image.processing.convolution.Laplacian3x3;
041
042/**
043 * Sharpness measures the clarity and level of detail of an image. This class
044 * measures the Sharpness of an image as a function of its Laplacian, normalized
045 * by the local average luminance in the surroundings of each pixel.
046 * 
047 * @author Jonathon Hare
048 * 
049 */
050@Reference(
051                type = ReferenceType.Inproceedings,
052                author = { "Jose San Pedro", "Stefan Siersdorfer" },
053                title = "Ranking and Classifying Attractiveness of Photos in Folksonomies",
054                year = "2009",
055                booktitle = "18th International World Wide Web Conference",
056                pages = { "771", "", "771" },
057                url = "http://www2009.eprints.org/78/",
058                month = "April")
059public class Sharpness extends AbstractMaskedObject<FImage>
060                implements
061                        ImageAnalyser<FImage>,
062                        FeatureVectorProvider<DoubleFV>
063{
064        private final Laplacian3x3 laplacian = new Laplacian3x3();
065        private final AverageBoxFilter average = new AverageBoxFilter(3, 3);
066
067        protected double sharpness;
068
069        /**
070         * Construct with no mask set
071         */
072        public Sharpness() {
073                super();
074        }
075
076        /**
077         * Construct with a mask.
078         * 
079         * @param mask
080         *            the mask.
081         */
082        public Sharpness(FImage mask) {
083                super(mask);
084        }
085
086        @Override
087        public DoubleFV getFeatureVector() {
088                return new DoubleFV(new double[] { sharpness });
089        }
090
091        @Override
092        public void analyseImage(FImage image) {
093                final FImage limg = image.process(laplacian);
094                final FImage aimg = image.process(average);
095
096                double sum = 0;
097                for (int r = 0; r < limg.height; r++) {
098                        for (int c = 0; c < limg.width; c++) {
099                                if (mask != null && mask.pixels[r][c] == 0)
100                                        continue;
101
102                                if (aimg.pixels[r][c] != 0) {
103                                        sum += Math.abs(limg.pixels[r][c] / aimg.pixels[r][c]);
104                                }
105                        }
106                }
107
108                sharpness = sum / (limg.height * limg.width);
109        }
110
111        /**
112         * Get the sharpness of the last image processed with
113         * {@link #analyseImage(FImage)}.
114         * 
115         * @return the sharpness value
116         */
117        public double getSharpness() {
118                return sharpness;
119        }
120}