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.gradient.dsift;
31
32 import java.io.Serializable;
33
34 import org.openimaj.feature.ArrayFeatureVector;
35 import org.openimaj.feature.local.LocalFeature;
36 import org.openimaj.feature.local.SpatialLocation;
37 import org.openimaj.io.VariableLength;
38
39 /**
40 * Abstract base for Dense SIFT keypoints with a location and vector. Also
41 * includes the energy of the feature prior to normalisation in case
42 * low-contrast features need removing.
43 *
44 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
45 *
46 * @param <T>
47 * Type of {@link ArrayFeatureVector} that this keypoint provides
48 * @param <Q>
49 * Type of primitive array backing the feature
50 */
51 abstract class AbstractDSIFTKeypoint<T extends ArrayFeatureVector<Q>, Q>
52 extends
53 SpatialLocation
54 implements
55 Serializable,
56 LocalFeature<SpatialLocation, T>,
57 VariableLength,
58 Cloneable
59 {
60 final static long serialVersionUID = 1234554345;
61
62 /**
63 * Default length of standard SIFT features.
64 */
65 final static int DEFAULT_LENGTH = 128;
66
67 /**
68 * The energy of the descriptor prior to normalisation; computed as the sum
69 * of descriptor values divided by the number of sample pixels used to
70 * create it (hence comparable across different window sizes). Can be used
71 * to remove low-contrast descriptors.
72 */
73 public float energy;
74
75 /**
76 * The descriptor (normalised)
77 */
78 public Q descriptor;
79
80 @Override
81 public SpatialLocation getLocation() {
82 return this;
83 }
84
85 @Override
86 public byte[] binaryHeader() {
87 return "".getBytes();
88 }
89
90 @Override
91 public String asciiHeader() {
92 return "";
93 }
94 }