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.convolution.filterbank;
031
032import org.openimaj.citation.annotation.Reference;
033import org.openimaj.citation.annotation.ReferenceType;
034import org.openimaj.image.processing.convolution.FConvolution;
035
036/**
037 * Base {@link FilterBank} that provides the 16 raw kernels used in Laws texture
038 * classification approach. These are used by the {@link LawsTexture} class to
039 * make 9 filters (by averaging the directional ones).
040 * <p>
041 * This class is provided as a convenience for extensions to Laws technique; in
042 * direct applications of Law's technique, you'll want to use
043 * {@link LawsTexture} instead.
044 * 
045 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
046 * 
047 */
048@Reference(
049                type = ReferenceType.Inproceedings,
050                author = { "Laws, K. I." },
051                title = "{Rapid Texture Identification}",
052                year = "1980",
053                booktitle = "Proc. SPIE Conf. Image Processing for Missile Guidance",
054                pages = { "376", "", "380" },
055                customData = {
056                                "citeulike-article-id", "2335645",
057                                "keywords", "bibtex-import",
058                                "posted-at", "2008-02-05 15:32:50",
059                                "priority", "2"
060                })
061public class LawsTextureBase extends FilterBank {
062        private static final float[] L5 = { 1, 4, 6, 4, 1 };
063        private static final float[] E5 = { -1, -2, 0, 2, 1 };
064        private static final float[] S5 = { -1, 0, 2, 0, -1 };
065        private static final float[] R5 = { 1, -4, 6, -4, 1 };
066
067        protected final static int L5E5 = 0;
068        protected final static int E5L5 = 1;
069        protected final static int L5R5 = 2;
070        protected final static int R5L5 = 3;
071        protected final static int E5S5 = 4;
072        protected final static int S5E5 = 5;
073        protected final static int S5S5 = 6;
074        protected final static int R5R5 = 7;
075        protected final static int L5S5 = 8;
076        protected final static int S5L5 = 9;
077        protected final static int E5E5 = 10;
078        protected final static int E5R5 = 11;
079        protected final static int R5E5 = 12;
080        protected final static int S5R5 = 13;
081        protected final static int R5S5 = 14;
082
083        /**
084         * Default constructor
085         */
086        public LawsTextureBase() {
087                super(makeFilters());
088        }
089
090        private static FConvolution[] makeFilters() {
091                final FConvolution[] filters = new FConvolution[15];
092
093                filters[L5E5] = makeFilter(L5, E5);
094                filters[E5L5] = makeFilter(E5, L5);
095                filters[L5R5] = makeFilter(L5, R5);
096                filters[R5L5] = makeFilter(R5, L5);
097                filters[E5S5] = makeFilter(E5, S5);
098                filters[S5E5] = makeFilter(S5, E5);
099                filters[S5S5] = makeFilter(S5, S5);
100                filters[R5R5] = makeFilter(R5, R5);
101                filters[L5S5] = makeFilter(L5, S5);
102                filters[S5L5] = makeFilter(S5, L5);
103                filters[E5E5] = makeFilter(E5, E5);
104                filters[E5R5] = makeFilter(E5, R5);
105                filters[R5E5] = makeFilter(R5, E5);
106                filters[S5R5] = makeFilter(S5, R5);
107                filters[R5S5] = makeFilter(R5, S5);
108
109                return filters;
110        }
111
112        private static FConvolution makeFilter(float[] l, float[] r) {
113                final float[][] f = new float[l.length][r.length];
114
115                for (int i = 0; i < l.length; i++)
116                        for (int j = 0; j < r.length; j++)
117                                f[i][j] = l[i] * r[j];
118
119                return new FConvolution(f);
120        }
121}