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.dense.binarypattern;
31
32 import org.openimaj.citation.annotation.Reference;
33 import org.openimaj.citation.annotation.ReferenceType;
34 import org.openimaj.image.FImage;
35 import org.openimaj.image.analyser.ImageAnalyser;
36 import org.openimaj.image.pixel.Pixel;
37
38 /**
39 * Implementation of the original 3x3 form of a local binary pattern.
40 *
41 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
42 */
43 @Reference(
44 type = ReferenceType.Article,
45 author = { "Ojala, T.", "Pietikainen, M.", "Harwood, D." },
46 title = "A Comparative Study of Texture Measures with Classification Based on Feature Distributions",
47 year = "1996",
48 journal = "Pattern Recognition",
49 pages = { "51", "59" },
50 month = "January",
51 number = "1",
52 volume = "29"
53 )
54 public class BasicLocalBinaryPattern implements ImageAnalyser<FImage> {
55 protected int[][] pattern = null;
56
57 /**
58 * Get the pattern created during the last call to
59 * {@link #analyseImage(FImage)}.
60 *
61 * @return the pattern
62 */
63 public int[][] getPattern() {
64 return pattern;
65 }
66
67 /**
68 * Calculate the LBP for every pixel in the image. The returned
69 * array of LBP codes has the same dimensions as the image.
70 *
71 * Samples taken from outside the image bounds are assumed to have
72 * the value 0.
73 *
74 * @param image the image
75 * @return a 2d-array of the LBP codes for every pixel
76 */
77 public static int[][] calculateLBP(FImage image) {
78 int [][] pattern = new int[image.height][image.width];
79
80 for (int y=0; y<image.height; y++) {
81 for (int x=0; x<image.width; x++) {
82 pattern[y][x] = calculateLBP(image, x, y);
83 }
84 }
85
86 return pattern;
87 }
88
89 /**
90 * Calculate the basic LBP for a single point. The
91 * point must be within the image.
92 *
93 * @param image the image
94 * @param x the x-coordinate of the point
95 * @param y the y-coordinate of the point
96 * @return the LBP code
97 */
98 public static int calculateLBP(FImage image, int x, int y) {
99 float thresh = image.pixels[y][x];
100 int i = 0;
101 int pattern = 0;
102
103 for (int yy=-1; yy<2; yy++) {
104 for (int xx=-1; xx<2; xx++) {
105 if (xx == 0 && yy == 0)
106 continue;
107
108 int xxx = x + xx;
109 int yyy = y + yy;
110 float pix = 0;
111
112 if (xxx >= 0 && xxx < image.width && yyy >= 0 && yyy < image.height) {
113 pix = image.pixels[yyy][xxx];
114 }
115
116 if (pix >= thresh) {
117 pattern += Math.pow(2, i);
118 }
119
120 i++;
121 }
122 }
123
124 return pattern;
125 }
126
127 /**
128 * Calculate the basic LBP for a single point. The
129 * point must be within the image.
130 *
131 * @param image the image
132 * @param point the point
133 * @return the LBP code
134 */
135 public static int calculateLBP(FImage image, Pixel point) {
136 return calculateLBP(image, point.x, point.y);
137 }
138
139 /* (non-Javadoc)
140 * @see org.openimaj.image.processor.ImageProcessor#processImage(org.openimaj.image.Image)
141 */
142 @Override
143 public void analyseImage(FImage image) {
144 pattern = calculateLBP(image);
145 }
146 }