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.analysis.algorithm.histogram.binning;
031
032import org.openimaj.image.analysis.algorithm.histogram.WindowedHistogramExtractor;
033import org.openimaj.math.geometry.shape.Rectangle;
034import org.openimaj.math.statistics.distribution.Histogram;
035
036/**
037 * Interface that describes the creation of a histogram from a spatial region of
038 * an image based on sub-histograms extracted using a
039 * {@link WindowedHistogramExtractor}.
040 * 
041 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
042 */
043public interface SpatialBinningStrategy {
044        /**
045         * Extract a histogram describing image content in the given region using
046         * the given {@link WindowedHistogramExtractor} to extract (sub) histograms
047         * from which to build the output.
048         * <p>
049         * For efficiency, this method allows the output histogram to be specified
050         * as an input. This means that implementors of this interface can attempt
051         * to fill the output histogram rather than creating a new instance
052         * (although care should be taken to ensure that the porivded output
053         * histogram is the correct size and not <code>null</code>).
054         * <p>
055         * Users of {@link SpatialBinningStrategy}s should use the following style
056         * for maximum efficiency: <code><pre>
057         * Histogram h = null;
058         * ...
059         * for (Rectangle region : lots_of_regions)
060         *      h = strategy.extract(binnedData, region, h);
061         * </pre></code>
062         * 
063         * @param binnedData
064         *            the {@link WindowedHistogramExtractor} to extract
065         *            sub-histograms from
066         * @param region
067         *            the region to extract from
068         * @param output
069         *            the output histogram to fill (can be null)
070         * @return the extracted histogram (preferably <code>output</code>)
071         */
072        public Histogram extract(WindowedHistogramExtractor binnedData, Rectangle region, Histogram output);
073}