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.image.segmentation;
31
32 import gnu.trove.map.hash.TFloatObjectHashMap;
33
34 import java.util.Arrays;
35 import java.util.List;
36
37 import org.openimaj.image.FImage;
38 import org.openimaj.image.pixel.PixelSet;
39 import org.openimaj.image.processor.Processor;
40
41 /**
42 * Simple wrapper to make thresholding algorithms into {@link Segmenter}s by
43 * applying the thresholding operation and then gathering the pixel sets
44 * belonging to each segment. Note that class does not perform connected
45 * component analysis, and for example in the case of binary thresholding, there
46 * will only be two {@link PixelSet}s produced (i.e. foreground and background).
47 *
48 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
49 *
50 */
51 public class ThresholdSegmenter implements Segmenter<FImage> {
52 Processor<FImage> thresholder;
53
54 /**
55 * Construct with the given thresholding algorithm implementation.
56 *
57 * @param thresholder
58 * the thresholding algorithm
59 */
60 public ThresholdSegmenter(Processor<FImage> thresholder) {
61 this.thresholder = thresholder;
62 }
63
64 @Override
65 public List<? extends PixelSet> segment(FImage image) {
66 final FImage timg = image.process(thresholder);
67 final TFloatObjectHashMap<PixelSet> sets = new TFloatObjectHashMap<PixelSet>();
68
69 for (int y = 0; y < timg.height; y++) {
70 for (int x = 0; x < timg.width; x++) {
71 final float p = image.getPixel(x, y);
72
73 PixelSet ps = sets.get(p);
74 if (ps == null)
75 sets.put(p, ps = new PixelSet());
76 ps.addPixel(x, y);
77 }
78 }
79
80 return Arrays.asList(sets.values());
81 }
82 }