/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
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 *      this list of conditions and the following disclaimer.
 *
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 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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package org.openimaj.image.feature.dense.gradient.dsift;

import org.openimaj.feature.local.list.LocalFeatureList;
import org.openimaj.image.Image;
import org.openimaj.image.analyser.ImageAnalyser;
import org.openimaj.math.geometry.shape.Rectangle;

/**
 * Base class for implementations of a dense SIFT feature extractors.
 * 
 * @see "http://www.vlfeat.org/api/dsift.html#dsift-usage"
 * 
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 * 
 * @param <IMAGE>
 *            Type of image being processed
 */
public abstract class AbstractDenseSIFT<IMAGE extends Image<?, IMAGE>> implements ImageAnalyser<IMAGE>, Cloneable {

        /**
         * Compute the dense sift descriptors inside the bounds rectangle of the
         * given image.
         * 
         * @param image
         *            the image
         * @param bounds
         *            the bounds rectangle
         */
        public abstract void analyseImage(IMAGE image, Rectangle bounds);

        /**
         * Compute the dense sift descriptors of the given image. The entire image
         * will be sampled.
         * 
         * @param image
         *            the image
         */
        @Override
        public final void analyseImage(IMAGE image) {
                analyseImage(image, image.getBounds());
        }

        /**
         * Get the SIFT descriptors from the previous call to
         * {@link #analyseImage(Image)} or {@link #analyseImage(Image, Rectangle)}
         * in the form of a list of local features with float vectors.
         * 
         * @return a list of {@link FloatDSIFTKeypoint}s.
         */
        public abstract LocalFeatureList<FloatDSIFTKeypoint> getFloatKeypoints();

        /**
         * Get the SIFT descriptors from the previous call to
         * {@link #analyseImage(Image)} or {@link #analyseImage(Image, Rectangle)}
         * in the form of a list of local features with byte vectors.
         * 
         * @return a list of {@link ByteDSIFTKeypoint}s.
         */
        public abstract LocalFeatureList<ByteDSIFTKeypoint> getByteKeypoints();

        /**
         * Get the SIFT descriptors from the previous call to
         * {@link #analyseImage(Image)} or {@link #analyseImage(Image, Rectangle)}
         * in the form of a list of local features with float vectors. Only the
         * features with an energy above the given threshold will be returned.
         * 
         * @param energyThreshold
         *            the threshold on the feature energy
         * 
         * @return a list of {@link FloatDSIFTKeypoint}s.
         */
        public abstract LocalFeatureList<FloatDSIFTKeypoint> getFloatKeypoints(float energyThreshold);

        /**
         * Get the SIFT descriptors from the previous call to
         * {@link #analyseImage(Image)} or {@link #analyseImage(Image, Rectangle)}
         * in the form of a list of local features with byte vectors. Only the
         * features with an energy above the given threshold will be returned.
         * 
         * @param energyThreshold
         *            the threshold on the feature energy
         * 
         * @return a list of {@link ByteDSIFTKeypoint}s.
         */
        public abstract LocalFeatureList<ByteDSIFTKeypoint> getByteKeypoints(float energyThreshold);

        @SuppressWarnings("unchecked")
        @Override
        public AbstractDenseSIFT<IMAGE> clone() {
                try {
                        return (AbstractDenseSIFT<IMAGE>) super.clone();
                } catch (final CloneNotSupportedException e) {
                        throw new AssertionError(e);
                }
        }

        /**
         * (Optional operation) Set the width of a single bin of the sampling window
         * (in pixels). Sampling window width is this multiplied by
         * {@link #getNumBinsX()}.
         * 
         * @param size
         *            size to set
         */
        public abstract void setBinWidth(int size);

        /**
         * (Optional operation) Set the height of a single bin of the sampling
         * window (in pixels). Sampling window height is this multiplied by
         * {@link #getNumBinsY()}.
         * 
         * @param size
         *            size to set
         */
        public abstract void setBinHeight(int size);

        /**
         * (Optional operation) Get the width of a single bin of the sampling window
         * (in pixels). Sampling window width is this multiplied by
         * {@link #getNumBinsX()}.
         * 
         * @return the bin width
         */
        public abstract int getBinWidth();

        /**
         * (Optional operation) Get the height of a single bin of the sampling
         * window (in pixels). Sampling window height is this multiplied by
         * {@link #getNumBinsY()}.
         * 
         * @return the bin height
         */
        public abstract int getBinHeight();

        /**
         * Get the number of spatial bins in the X direction
         * 
         * @return the number of bins in the x direction
         */
        public abstract int getNumBinsX();

        /**
         * Get the number of spatial bins in the Y direction
         * 
         * @return the number of bins in the y direction
         */
        public abstract int getNumBinsY();

        /**
         * Get the number of orientation bins
         * 
         * @return the number of orientation bins
         */
        public abstract int getNumOriBins();

        /**
         * Get the computed raw dense SIFT descriptors from the previous call to
         * {@link #analyseImage(Image)} or {@link #analyseImage(Image, Rectangle)} .
         * 
         * @return the descriptors.
         */
        public abstract float[][] getDescriptors();
}