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.residuals;
031
032import java.util.List;
033
034import org.openimaj.math.geometry.point.Point2d;
035import org.openimaj.math.geometry.transforms.MatrixTransformProvider;
036import org.openimaj.math.model.Model;
037import org.openimaj.math.model.fit.residuals.ResidualCalculator;
038import org.openimaj.util.pair.IndependentPair;
039
040import Jama.Matrix;
041
042/**
043 * The points in the first image are projected by the homography matrix to
044 * produce new estimates of the second image points and the second image point
045 * projected by the inverse homography to produce estimates of the first.
046 * Residuals are computed from both point sets and summed to produce the final
047 * geometric residual value.
048 * 
049 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
050 * 
051 * @param <M>
052 */
053public class SymmetricTransferResidual2d<M extends Model<Point2d, Point2d> & MatrixTransformProvider>
054                implements
055                ResidualCalculator<Point2d, Point2d, M>
056{
057        private Matrix transform;
058        private Matrix transformInv;
059
060        @Override
061        public void setModel(M model) {
062                this.transform = model.getTransform();
063
064                if (transform.getRowDimension() != 3 || transform.getColumnDimension() != 3)
065                        throw new IllegalArgumentException("Transform matrix must be 3x3");
066
067                transformInv = transform.inverse();
068        }
069
070        @Override
071        public double computeResidual(IndependentPair<Point2d, Point2d> data) {
072                final Point2d p1 = data.getFirstObject();
073                final Point2d p2 = data.getSecondObject();
074
075                final Point2d p1t = p1.transform(transform);
076                final Point2d p2t = p2.transform(transformInv);
077
078                final float p1x = p1.getX();
079                final float p1y = p1.getY();
080                final float p1tx = p1t.getX();
081                final float p1ty = p1t.getY();
082                final float p2x = p2.getX();
083                final float p2y = p2.getY();
084                final float p2tx = p2t.getX();
085                final float p2ty = p2t.getY();
086
087                final float dx12t = (p1x - p2tx);
088                final float dy12t = (p1y - p2ty);
089                final float dx1t2 = (p1tx - p2x);
090                final float dy1t2 = (p1ty - p2y);
091
092                return dx12t * dx12t + dy12t * dy12t + dx1t2 * dx1t2 + dy1t2 * dy1t2;
093        }
094
095        @Override
096        public void computeResiduals(List<? extends IndependentPair<Point2d, Point2d>> data, double[] residuals) {
097                for (int i = 0; i < data.size(); i++) {
098                        residuals[i] = computeResidual(data.get(i));
099                }
100        }
101}