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.analysis.algorithm.histogram.binning;
31
32 import java.util.List;
33
34 import org.openimaj.image.analysis.algorithm.histogram.WindowedHistogramExtractor;
35 import org.openimaj.image.pixel.sampling.QuadtreeSampler;
36 import org.openimaj.math.geometry.shape.Rectangle;
37 import org.openimaj.math.statistics.distribution.Histogram;
38
39 /**
40 * A {@link SpatialBinningStrategy} that extracts histograms from regions
41 * defined by a fixed depth quadtree overlayed over the sampling region and
42 * concatenates them together.
43 *
44 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
45 */
46 public class QuadtreeStrategy implements SpatialBinningStrategy {
47 int nlevels;
48
49 /**
50 * Construct with the given quadtree depth
51 *
52 * @param nlevels
53 * quadtree depth
54 */
55 public QuadtreeStrategy(int nlevels) {
56 this.nlevels = nlevels;
57 }
58
59 @Override
60 public Histogram extract(WindowedHistogramExtractor binnedData, Rectangle region, Histogram output) {
61 final QuadtreeSampler sampler = new QuadtreeSampler(region, nlevels);
62 final int blockSize = binnedData.getNumBins();
63 final List<Rectangle> rects = sampler.allRectangles();
64
65 if (output == null || output.values.length != blockSize * rects.size())
66 output = new Histogram(blockSize * rects.size());
67
68 final Histogram tmp = new Histogram(blockSize);
69 for (int i = 0; i < rects.size(); i++) {
70 final Rectangle r = rects.get(i);
71
72 binnedData.computeHistogram(r, tmp);
73
74 System.arraycopy(tmp.values, 0, output.values, blockSize * i, blockSize);
75 }
76
77 return output;
78 }
79 }