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.contour;
031
032import org.openimaj.image.FImage;
033import org.openimaj.image.pixel.Pixel;
034import org.openimaj.util.function.Operation;
035import org.openimaj.util.pair.IndependentPair;
036
037/**
038 * The Moore Neighborhood contour tracing strategy as described by <a href=
039 * "http://www.imageprocessingplace.com/downloads_V3/root_downloads/tutorials/contour_tracing_Abeer_George_Ghuneim/moore.html"
040 * >this tutorial</a>.
041 * 
042 * @author Sina Samangooei (ss@ecs.soton.ac.uk)
043 * 
044 */
045public class MooreNeighborStrategy extends ContourFollowingStrategy {
046
047        @Override
048        public void contour(FImage image, Pixel start, Pixel from, final Operation<Pixel> operation) {
049                directedContour(image, start, from, new Operation<IndependentPair<Pixel, Direction>>() {
050                        @Override
051                        public void perform(IndependentPair<Pixel, Direction> object) {
052                                operation.perform(object.firstObject());
053                        }
054                });
055        }
056
057        /**
058         * Directed contour following.
059         * 
060         * @param image
061         *            the image
062         * @param start
063         *            the starting point on the contour
064         * @param from
065         *            the pixel that was not a contour
066         * @param operation
067         *            the operation to perform
068         */
069        public void directedContour(FImage image, Pixel start, Pixel from,
070                        Operation<IndependentPair<Pixel, Direction>> operation)
071        {
072                Pixel p = start;
073                if (image.pixels[start.y][start.x] == 0)
074                        return;
075                Direction cdirStart = Direction.fromTo(p, from);
076                operation.perform(IndependentPair.pair(start, cdirStart));
077                final Direction firstCdir = cdirStart;
078                Direction cdir = cdirStart.clockwise();
079                int startCount = 0;
080                while (cdir != cdirStart) {
081                        final Pixel c = cdir.active(image, p);
082                        if (c != null) {
083                                cdirStart = cdir.clockwiseEntryDirection();
084                                if (c.equals(start)) {
085                                        startCount++;
086                                        if (startCount >= 2 || firstCdir == cdirStart) {
087                                                return;
088                                        }
089
090                                }
091                                operation.perform(IndependentPair.pair(c, cdirStart));
092                                p = c;
093                                cdir = cdirStart.clockwise();
094                        }
095                        else {
096                                cdir = cdir.clockwise();
097                        }
098                }
099        }
100
101}