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.feature;
031
032/**
033 * An adaptor for {@link FeatureExtractor}s that return objects that are
034 * {@link FeatureVectorProvider}s that is a {@link FeatureExtractor} that
035 * returns a {@link FeatureVector}.
036 * 
037 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
038 * 
039 * @param <FV>
040 *            Type of {@link FeatureVector}
041 * @param <OBJECT>
042 *            Type of object the extractor works on.
043 */
044public class FVProviderExtractor<FV extends FeatureVector, OBJECT>
045                implements FeatureExtractor<FV, OBJECT>
046{
047        /**
048         * The internal extractor
049         */
050        public FeatureExtractor<? extends FeatureVectorProvider<FV>, OBJECT> extractor;
051
052        /**
053         * Construct with the given extractor.
054         * 
055         * @param extractor
056         *            the extractor
057         */
058        public FVProviderExtractor(FeatureExtractor<? extends FeatureVectorProvider<FV>, OBJECT> extractor) {
059                this.extractor = extractor;
060        }
061
062        @Override
063        public FV extractFeature(OBJECT object) {
064                return extractor.extractFeature(object).getFeatureVector();
065        }
066
067        /**
068         * Create a new {@link FVProviderExtractor} with the given extractor.
069         * 
070         * @param extractor
071         *            the extractor
072         * 
073         * @param <FV>
074         *            Type of {@link FeatureVector}
075         * @param <OBJECT>
076         *            Type of object the extractor works on.
077         * @param <EXTRACTOR>
078         *            Type of extractor.
079         * 
080         * @return the new {@link FVProviderExtractor}
081         */
082        public static <FV extends FeatureVector, OBJECT, EXTRACTOR extends FeatureExtractor<? extends FeatureVectorProvider<FV>, OBJECT>>
083                        FVProviderExtractor<FV, OBJECT>
084                        create(EXTRACTOR extractor)
085        {
086                return new FVProviderExtractor<FV, OBJECT>(extractor);
087        }
088}