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.connectedcomponent.proc; 031 032import org.openimaj.feature.DoubleFV; 033import org.openimaj.feature.FeatureVectorProvider; 034import org.openimaj.image.pixel.ConnectedComponent; 035import org.openimaj.image.processor.connectedcomponent.ConnectedComponentProcessor; 036 037 038/** 039 * Implementation of the 7 Hu moments for describing 040 * connected component shape. 041 * 042 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk) 043 */ 044public class HuMoments implements ConnectedComponentProcessor, FeatureVectorProvider<DoubleFV> { 045 /** 046 * The first Hu moment 047 */ 048 public double h1; 049 050 /** 051 * The second Hu moment 052 */ 053 public double h2; 054 055 /** 056 * The third Hu moment 057 */ 058 public double h3; 059 060 /** 061 * The forth Hu moment 062 */ 063 public double h4; 064 065 /** 066 * The fifth Hu moment 067 */ 068 public double h5; 069 070 /** 071 * The sixth Hu moment 072 */ 073 public double h6; 074 075 /** 076 * The seventh Hu moment 077 */ 078 public double h7; 079 080 @Override 081 public void process(ConnectedComponent cc) { 082 double v11 = cc.calculateMomentNormalised(1, 1); 083 084 double v12 = cc.calculateMomentNormalised(1, 2); 085 double v21 = cc.calculateMomentNormalised(2, 1); 086 087 double v02 = cc.calculateMomentNormalised(0, 2); 088 double v20 = cc.calculateMomentNormalised(2, 0); 089 090 double v03 = cc.calculateMomentNormalised(0, 3); 091 double v30 = cc.calculateMomentNormalised(3, 0); 092 093 h1 = v20 + v02; 094 h2 = ((v20 - v02) * (v20 - v02)) + (4 * v11 * v11); 095 h3 = ((v30 - 3*v12)*(v30 - 3*v12)) + ((3*v21 - v03)*(3*v21 - v03)); 096 h4 = ((v30+v12)*(v30+v12)) + ((v21+v03)*(v21+v03)); 097 h5 = (((v30 - 3*v12)*(v30+v12)) * (((v30+v12)*(v30+v12) - (3*(v21+v03)*(v21+v03))))) + 098 (((3*v21-v03)*(v21+v03)) * ((3*(v30+v12)*(v30+v12)) - (v21+v03)*(v21+v03))); 099 h6 = ((v20 - v02) * ((v30+v12)*(v30+v12) - (v21 + v03)*(v21 + v03))) + (4*v11*(v30+v12)*(v21+v03)); 100 h7 = ((3*v21 - v03)*(v30+v12)*((v30+v12)*(v30+v12) - 3*(v21+v03)*(v21+v03))) - 101 ((v30-3*v12)*(v21+v03)*(3*(v30+v12)*(v30+v12) - (v21+v03)*(v21+v03))); 102 } 103 104 @Override 105 public String toString() { 106 return String.format("%2.2f, %2.2f, %2.2f, %2.2f, %2.2f, %2.2f, %2.2f", h1, h2, h3, h4, h5, h6, h7); 107 } 108 109 /** 110 * Get all the values of the descriptor as an array. 111 * @return an array of descriptor values 112 */ 113 public double[] getFeatureVectorArray() { 114 return new double[] {h1, h2, h3, h4, h5, h6, h7}; 115 } 116 117 @Override 118 public DoubleFV getFeatureVector() { 119 return new DoubleFV(getFeatureVectorArray()); 120 } 121} 122