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 static java.lang.Math.PI; 033 034import org.openimaj.image.processing.convolution.FConvolution; 035import org.openimaj.image.processing.convolution.Gaussian2D; 036import org.openimaj.image.processing.convolution.LaplacianOfGaussian2D; 037 038/** 039 * Implementation of the Root Filter Set filter bank described at: 040 * http://www.robots.ox.ac.uk/~vgg/research/texclass/filters.html 041 * 042 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk) 043 */ 044 045public class RootFilterSetFilterBank extends FilterBank { 046 protected final static float[] SCALES = { 1, 2, 4 }; 047 protected final static int NUM_ORIENTATIONS = 6; 048 049 /** 050 * Default constructor with a support of 49 pixels. 051 */ 052 public RootFilterSetFilterBank() { 053 this(49); 054 } 055 056 /** 057 * Construct with given support (filter size). 058 * 059 * @param size 060 * the filter size 061 */ 062 public RootFilterSetFilterBank(int size) { 063 super(makeFilters(size)); 064 } 065 066 protected static FConvolution[] makeFilters(int size) { 067 final int numRotInvariants = 2; 068 final int numBar = SCALES.length * NUM_ORIENTATIONS; 069 final int numEdge = SCALES.length * NUM_ORIENTATIONS; 070 final int numFilters = numBar + numEdge + numRotInvariants; 071 final FConvolution[] F = new FConvolution[numFilters]; 072 073 int count = 0; 074 for (final float scale : SCALES) { 075 for (int orient = 0; orient < NUM_ORIENTATIONS; orient++) { 076 final float angle = (float) (PI * orient / NUM_ORIENTATIONS); 077 078 F[count] = new FConvolution(LeungMalikFilterBank.makeFilter(scale, 0, 1, angle, size)); 079 F[count + numEdge] = new FConvolution(LeungMalikFilterBank.makeFilter(scale, 0, 2, angle, size)); 080 count++; 081 } 082 } 083 084 F[numBar + numEdge] = new FConvolution(Gaussian2D.createKernelImage(size, 10)); // don't 085 // normalise 086 F[numBar + numEdge + 1] = new FConvolution(LeungMalikFilterBank.normalise(LaplacianOfGaussian2D 087 .createKernelImage(size, 10))); 088 089 return F; 090 } 091}