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.math.geometry.transforms;
031
032import java.util.List;
033
034import org.openimaj.math.geometry.point.Point2d;
035import org.openimaj.math.model.EstimatableModel;
036import org.openimaj.util.function.Predicate;
037import org.openimaj.util.pair.IndependentPair;
038
039import Jama.Matrix;
040
041/**
042 * Concrete implementation of a model of an Affine transform. Capable of
043 * least-squares estimate of model parameters using the SVD.
044 *
045 * @author Jonathon Hare
046 *
047 */
048public class AffineTransformModel implements EstimatableModel<Point2d, Point2d>, MatrixTransformProvider {
049        protected Predicate<AffineTransformModel> modelCheck;
050        protected Matrix transform;
051
052        /**
053         * Create an {@link AffineTransformModel}
054         */
055        public AffineTransformModel()
056        {
057                transform = new Matrix(3, 3);
058
059                transform.set(2, 0, 0);
060                transform.set(2, 1, 0);
061                transform.set(2, 2, 1);
062        }
063
064        /**
065         * Create an {@link AffineTransformModel}. The given {@link Predicate} is
066         * used by the {@link #estimate(List)} method to test whether the estimated
067         * affine transform is sensible.
068         *
069         * @param mc
070         *            the test function for sensible affine transforms
071         */
072        public AffineTransformModel(Predicate<AffineTransformModel> mc)
073        {
074                this.modelCheck = mc;
075                transform = new Matrix(3, 3);
076
077                transform.set(2, 0, 0);
078                transform.set(2, 1, 0);
079                transform.set(2, 2, 1);
080        }
081
082        @Override
083        public AffineTransformModel clone() {
084                final AffineTransformModel atm = new AffineTransformModel();
085                atm.modelCheck = modelCheck;
086                atm.transform = transform.copy();
087                return atm;
088        }
089
090        @Override
091        public Matrix getTransform() {
092                return transform;
093        }
094
095        /*
096         * SVD least-squares estimation of affine transform matrix for a set of 2d
097         * points
098         */
099        @Override
100        public boolean estimate(List<? extends IndependentPair<Point2d, Point2d>> data) {
101                if (data.size() < numItemsToEstimate())
102                        return false;
103
104                this.transform = TransformUtilities.affineMatrix(data);
105
106                if (modelCheck == null)
107                        return true;
108
109                return modelCheck.test(this);
110        }
111
112        @Override
113        public Point2d predict(Point2d p) {
114                return p.transform(transform);
115        }
116
117        @Override
118        public int numItemsToEstimate() {
119                return 3;
120        }
121
122        @Override
123        public String toString() {
124                String str = "";
125                final double[][] mat = transform.getArray();
126                for (final double[] r : mat) {
127                        for (final double v : r) {
128                                str += " " + v;
129                        }
130                        str += "\n";
131                }
132                return str;
133        }
134}