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.processing.morphology;
031
032import org.openimaj.image.FImage;
033import org.openimaj.image.pixel.ConnectedComponent;
034import org.openimaj.image.processor.ImageProcessor;
035import org.openimaj.image.processor.connectedcomponent.ConnectedComponentProcessor;
036
037/**
038 * Morphological sequential thinning of connected components and (assumed binary) FImages.
039 * 
040 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
041 */
042public class SequentialThin implements ConnectedComponentProcessor, ImageProcessor<FImage> {
043        protected HitAndMiss hitAndMiss;
044        protected int niter = -1;
045        
046        /**
047         * Construct the sequential thin operator with the given structuring elements
048         * @param se the structuring elements
049         */
050        public SequentialThin(StructuringElement... se) {
051                this.hitAndMiss = new HitAndMiss(se);
052        }
053        
054        /**
055         * Construct the sequential thin operator with the given structuring elements
056         * and number of iterations
057         * @param niter number of iterations to apply
058         * @param se the structuring elements
059         */
060        public SequentialThin(int niter, StructuringElement... se) {
061                this.hitAndMiss = new HitAndMiss(se);
062                this.niter = niter;
063        }
064        
065        @Override
066        public void process(ConnectedComponent cc) {            
067                for (int i=niter; i!=0; i--) {
068                        hitAndMiss.process(cc);
069                        
070                        if (hitAndMiss.outputPixels.size() == 0)
071                                break;
072                        
073                        cc.getPixels().removeAll(hitAndMiss.outputPixels);
074                }
075        }
076
077        /* (non-Javadoc)
078         * @see org.openimaj.image.processor.ImageProcessor#processImage(org.openimaj.image.Image)
079         */
080        @Override
081        public void processImage(FImage image) {
082                for (int i=niter; i!=0; i--) {
083                        FImage newImage = image.process(hitAndMiss, true);
084                        
085                        int count = 0;
086                        for (int y=0; y<newImage.height; y++) {
087                                for (int x=0; x<newImage.width; x++) {
088                                        if (newImage.pixels[y][x] == 1) {
089                                                count++;
090                                                image.pixels[y][x] = 0;
091                                        }
092                                }
093                        }
094                        
095                        if (count == 0)
096                                break;
097                }
098        }
099}