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.processing.algorithm;
31
32 import org.openimaj.image.FImage;
33 import org.openimaj.image.processing.convolution.FGaussianConvolve;
34 import org.openimaj.image.processor.ImageProcessor;
35
36 /**
37 * Implementation of a difference of Gaussian filter.
38 *
39 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
40 *
41 */
42 public class DifferenceOfGaussian implements ImageProcessor<FImage> {
43 FGaussianConvolve filter1;
44 FGaussianConvolve filter2;
45
46 /**
47 * Construct a difference of Gaussian with the default sigmas
48 * of 1 and 2.
49 */
50 public DifferenceOfGaussian() {
51 this(1, 2);
52 }
53
54 /**
55 * Construct a difference of Gaussian with the specified
56 * sigmas.
57 * @param sigma1 first (smaller sigma)
58 * @param sigma2 second sigma
59 */
60 public DifferenceOfGaussian(float sigma1, float sigma2) {
61 filter1 = new FGaussianConvolve(sigma1);
62 filter2 = new FGaussianConvolve(sigma2);
63 }
64
65 /* (non-Javadoc)
66 * @see org.openimaj.image.processor.ImageProcessor#processImage(org.openimaj.image.Image)
67 */
68 @Override
69 public void processImage(FImage image) {
70 FImage blur1 = image.process(filter1);
71 FImage blur2 = image.process(filter2);
72
73 image.internalAssign(blur1.subtractInplace(blur2));
74 }
75 }