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1   /**
2    * Copyright (c) 2011, The University of Southampton and the individual contributors.
3    * All rights reserved.
4    *
5    * Redistribution and use in source and binary forms, with or without modification,
6    * are permitted provided that the following conditions are met:
7    *
8    *   * 	Redistributions of source code must retain the above copyright notice,
9    * 	this list of conditions and the following disclaimer.
10   *
11   *   *	Redistributions in binary form must reproduce the above copyright notice,
12   * 	this list of conditions and the following disclaimer in the documentation
13   * 	and/or other materials provided with the distribution.
14   *
15   *   *	Neither the name of the University of Southampton nor the names of its
16   * 	contributors may be used to endorse or promote products derived from this
17   * 	software without specific prior written permission.
18   *
19   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
20   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
23   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
26   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29   */
30  package org.openimaj.experiment.gmm.retrieval;
31  
32  import org.openimaj.feature.FeatureVector;
33  import org.openimaj.feature.local.LocalFeature;
34  import org.openimaj.feature.local.list.LocalFeatureList;
35  import org.openimaj.math.statistics.distribution.MixtureOfGaussians;
36  import org.openimaj.ml.gmm.GaussianMixtureModelEM;
37  import org.openimaj.ml.gmm.GaussianMixtureModelEM.CovarianceType;
38  import org.openimaj.util.array.ArrayUtils;
39  import org.openimaj.util.function.Function;
40  
41  import Jama.Matrix;
42  
43  /**
44   * This function turns a list of features to a gaussian mixture model
45   * 
46   * @author Sina Samangooei (ss@ecs.soton.ac.uk)
47   */
48  public class GMMFromFeatures implements Function<
49  			LocalFeatureList<? extends LocalFeature<?,? extends FeatureVector>>, 
50  			MixtureOfGaussians
51  		>
52  {
53  	
54  	/**
55  	 * default number of guassians to train agains
56  	 */
57  	public static final int DEFAULT_COMPONENTS = 10;
58  	/**
59  	 * default covariance type
60  	 */
61  	public static final CovarianceType DEFAULT_COVARIANCE = GaussianMixtureModelEM.CovarianceType.Spherical;
62  	
63  	private GaussianMixtureModelEM gmm;
64  	/**
65  	 * Defaults to {@link #DEFAULT_COMPONENTS} and 
66  	 */
67  	public GMMFromFeatures() {
68  		this.gmm = new GaussianMixtureModelEM(DEFAULT_COMPONENTS, DEFAULT_COVARIANCE);
69  	}
70  	
71  	/**
72  	 * @param type
73  	 */
74  	public GMMFromFeatures(CovarianceType type) {
75  		this.gmm = new GaussianMixtureModelEM(DEFAULT_COMPONENTS, type);
76  	}
77  	
78  	/**
79  	 * @param nComps
80  	 */
81  	public GMMFromFeatures(int nComps) {
82  		this.gmm = new GaussianMixtureModelEM(nComps, DEFAULT_COVARIANCE);
83  	}
84  	
85  	/**
86  	 * @param nComps
87  	 * @param type
88  	 */
89  	public GMMFromFeatures(int nComps,CovarianceType type) {
90  		this.gmm = new GaussianMixtureModelEM(nComps, type);
91  	}
92  	
93  	@Override
94  	public MixtureOfGaussians apply(LocalFeatureList<? extends LocalFeature<?,? extends FeatureVector>> features) {
95  		System.out.println("Creating double array...");
96  		double[][] doubleFeatures = new double[features.size()][];
97  		int i = 0;
98  		for (LocalFeature<?,?> localFeature : features) {			
99  			doubleFeatures[i] = ArrayUtils.divide(localFeature.getFeatureVector().asDoubleVector(), 128);
100 			i++;
101 		}
102 		System.out.println(String.format("Launching EM with double array: %d x %d",doubleFeatures.length,doubleFeatures[0].length));
103 		return this.gmm.estimate(new Matrix(doubleFeatures));
104 	}
105 
106 
107 
108 }