001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.image.feature.local.descriptor;
031
032import org.openimaj.feature.FeatureVector;
033import org.openimaj.feature.FeatureVectorProvider;
034import org.openimaj.image.feature.local.descriptor.gradient.SIFTFeatureProvider;
035
036/**
037 * Base interface for classes capable of building local descriptors.
038 * Local descriptors are constructed by being handed
039 * values in a unit square sampling patch (the patch itself in
040 * terms of image coordinates doesn't have to be square, but the 
041 * coordinates will be normalised to lie in a unit square).
042 * 
043 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
044 * @param <T> The type of {@link FeatureVector}
045 * 
046 */
047public interface LocalFeatureProvider<T extends FeatureVector> extends FeatureVectorProvider<T> {   
048        /**
049         * Get the amount of required over-sampling outside of 
050         * the unit square patch. An oversampling of 0.5 would
051         * result in methods such as {@link SIFTFeatureProvider#addSample(float, float, float, float)}
052         * being called with pixels in the range -0.5 to 1.5.
053         * @return the amount over sampling above the unit square
054         */
055        public abstract float getOversamplingAmount();
056}