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.ml.annotation;
031
032import java.util.List;
033import java.util.Set;
034
035import org.openimaj.data.dataset.cache.GroupedListCache;
036import org.openimaj.data.dataset.cache.InMemoryGroupedListCache;
037import org.openimaj.feature.FeatureExtractor;
038import org.openimaj.feature.IdentityFeatureExtractor;
039
040/**
041 * Adaptor that allows a {@link BatchAnnotator} to behave like a
042 * {@link IncrementalAnnotator} by caching extracted features and then
043 * performing training only when {@link #annotate(Object)} is called.
044 * <p>
045 * Because the features are cached, the internal annotator must rely on a
046 * {@link IdentityFeatureExtractor} or similar, and thus not perform any
047 * extraction itself.
048 *
049 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
050 *
051 * @param <OBJECT>
052 *            Type of object
053 * @param <ANNOTATION>
054 *            Type of annotation
055 * @param <FEATURE>
056 *            Type of feature extracted and cached.
057 */
058public class FeatureCachingIncrementalBatchAnnotator<OBJECT, ANNOTATION, FEATURE>
059extends IncrementalAnnotator<OBJECT, ANNOTATION>
060{
061        BatchAnnotator<FEATURE, ANNOTATION> batchAnnotator;
062        GroupedListCache<ANNOTATION, FEATURE> featureCache;
063        private FeatureExtractor<FEATURE, OBJECT> extractor;
064        boolean isInvalid = true;
065
066        /**
067         * Construct with the given feature extractor and batch annotator, and use
068         * an in-memory cache.
069         *
070         * @param extractor
071         *            the extractor
072         * @param batchAnnotator
073         *            the annotator
074         */
075        public FeatureCachingIncrementalBatchAnnotator(FeatureExtractor<FEATURE, OBJECT> extractor,
076                        BatchAnnotator<FEATURE, ANNOTATION> batchAnnotator)
077        {
078                this.extractor = extractor;
079                this.featureCache = new InMemoryGroupedListCache<ANNOTATION, FEATURE>();
080                this.batchAnnotator = batchAnnotator;
081        }
082
083        /**
084         * Construct with the given feature extractor and batch annotator, and use
085         * an in-memory cache.
086         *
087         * @param extractor
088         *            the extractor
089         * @param batchAnnotator
090         *            the annotator
091         * @param cache
092         *            the cache
093         */
094        public FeatureCachingIncrementalBatchAnnotator(FeatureExtractor<FEATURE, OBJECT> extractor,
095                        BatchAnnotator<FEATURE, ANNOTATION> batchAnnotator,
096                        GroupedListCache<ANNOTATION, FEATURE> cache)
097        {
098                this.extractor = extractor;
099                this.batchAnnotator = batchAnnotator;
100                this.featureCache = cache;
101        }
102
103        @Override
104        public void train(Annotated<OBJECT, ANNOTATION> annotated) {
105                final FEATURE fv = extractor.extractFeature(annotated.getObject());
106
107                featureCache.add(annotated.getAnnotations(), fv);
108                isInvalid = true;
109        }
110
111        @Override
112        public void reset() {
113                featureCache.reset();
114                isInvalid = true;
115        }
116
117        @Override
118        public Set<ANNOTATION> getAnnotations() {
119                return featureCache.getDataset().getGroups();
120        }
121
122        @Override
123        public List<ScoredAnnotation<ANNOTATION>> annotate(OBJECT object) {
124                if (isInvalid) {
125                        batchAnnotator.train(featureCache.getDataset());
126                        isInvalid = false;
127                }
128
129                return batchAnnotator.annotate(extractor.extractFeature(object));
130        }
131}