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.feature.global;
31
32 import org.openimaj.citation.annotation.Reference;
33 import org.openimaj.citation.annotation.ReferenceType;
34 import org.openimaj.feature.DoubleFV;
35 import org.openimaj.feature.FeatureVectorProvider;
36 import org.openimaj.image.FImage;
37 import org.openimaj.image.MBFImage;
38 import org.openimaj.image.analyser.ImageAnalyser;
39 import org.openimaj.image.colour.ColourSpace;
40
41 /**
42 * Implementation of the RGB RMS contrast feature.
43 * <p>
44 * See the referenced paper for a description. The original python looked like:
45 * <code><pre>
46 * cdata = image.getdata()
47 * center = [0.0,0.0,0.0]
48 *
49 * for v in cdata:
50 * center[0]+=v[0]
51 * center[1]+=v[1]
52 * center[2]+=v[2]
53 *
54 * for i in xrange(len(center)):
55 * center[i]/=len(cdata) #mean vector of the RGB values
56 *
57 * contrast2 = 0.0
58 * for v in cdata:
59 * contrast2 += ((v[0]-center[0])**2) + ((v[1]-center[1])**2) + ((v[2]-center[2])**2) #norm of differences wrt the mean
60 * contrast2 /= len(cdata)
61 * </pre></code>
62 *
63 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
64 */
65 @Reference(
66 type = ReferenceType.Inproceedings,
67 author = { "Jose San Pedro", "Stefan Siersdorfer" },
68 title = "Ranking and Classifying Attractiveness of Photos in Folksonomies",
69 year = "2009",
70 booktitle = "18th International World Wide Web Conference",
71 pages = { "771", "", "771" },
72 url = "http://www2009.eprints.org/78/",
73 month = "April")
74 public class RGBRMSContrast implements ImageAnalyser<MBFImage>, FeatureVectorProvider<DoubleFV> {
75 double contrast;
76
77 @Override
78 public DoubleFV getFeatureVector() {
79 return new DoubleFV(new double[] { contrast });
80 }
81
82 /*
83 * (non-Javadoc)
84 *
85 * @see
86 * org.openimaj.image.processor.ImageProcessor#processImage(org.openimaj
87 * .image.Image)
88 */
89 @Override
90 public void analyseImage(MBFImage image) {
91 final int width = image.getWidth();
92 final int height = image.getHeight();
93
94 image = ColourSpace.convert(image, ColourSpace.RGB);
95
96 final FImage r = image.getBand(0);
97 final FImage g = image.getBand(1);
98 final FImage b = image.getBand(2);
99
100 double avgr = 0;
101 double avgg = 0;
102 double avgb = 0;
103 for (int y = 0; y < height; y++) {
104 for (int x = 0; x < width; x++) {
105 avgr += r.pixels[y][x];
106 avgg += g.pixels[y][x];
107 avgb += b.pixels[y][x];
108 }
109 }
110 avgr /= (width * height);
111 avgg /= (width * height);
112 avgb /= (width * height);
113
114 contrast = 0;
115 for (int y = 0; y < height; y++) {
116 for (int x = 0; x < width; x++) {
117 final double deltar = r.pixels[y][x] - avgr;
118 final double deltag = g.pixels[y][x] - avgg;
119 final double deltab = b.pixels[y][x] - avgb;
120
121 contrast += (deltar * deltar) + (deltag * deltag) + (deltab * deltab);
122 }
123 }
124
125 contrast /= (height * width);
126 }
127
128 /**
129 * Get the contrast of the last image analysed with
130 * {@link #analyseImage(MBFImage)}
131 *
132 * @return the contrast
133 */
134 public double getContrast() {
135 return contrast;
136 }
137 }