/**
 * 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:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  Redistributions in binary form must reproduce the above copyright notice,
 *      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
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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package org.openimaj.image.feature.dense.gradient.dsift;

import org.openimaj.feature.local.list.LocalFeatureList;
import org.openimaj.feature.local.list.MemoryLocalFeatureList;
import org.openimaj.image.MBFImage;
import org.openimaj.image.colour.ColourSpace;
import org.openimaj.math.geometry.shape.Rectangle;

/**
 * Implementation of colour dense-sift. The algorithm works by applying the
 * {@link DenseSIFT} extractor to each channel of the image (in the target
 * {@link ColourSpace}) and then aggregating the descriptors across all
 * {@link ColourSpace}s for the same spatial location.
 * <p>
 * Any {@link ColourSpace} can be used. To compute the contrast energy of a
 * descriptor, the luminance is extracted across channels using
 * {@link ColourSpace#computeIntensity(float[])}. This means that if you choose
 * a {@link ColourSpace} that doesn't support intensities, then the contrast
 * energy will be zero. In practice this should not matter as it's most usual to
 * use the {@link ColourSpace#RGB}, {@link ColourSpace#HSV} or
 * {@link ColourSpace#OPPONENT} colour spaces, which can compute intensities.
 * 
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 * 
 */
public class ColourDenseSIFT extends AbstractDenseSIFT<MBFImage> {
        DenseSIFT dsift;
        ColourSpace colourSpace;

        volatile float[][] descriptors;
        volatile float[] energies;

        /**
         * Construct with the given internal {@link DenseSIFT} extractor to apply to
         * each band of the image created by converting the input to
         * {@link #analyseImage(MBFImage)} or
         * {@link #analyseImage(MBFImage, Rectangle)} to the given
         * {@link ColourSpace}.
         * 
         * @param dsift
         *            the dense sift extractor
         * @param colourSpace
         *            the target colour space
         */
        public ColourDenseSIFT(DenseSIFT dsift, ColourSpace colourSpace) {
                this.dsift = dsift;
                this.colourSpace = colourSpace;
        }

        @Override
        public void analyseImage(MBFImage image, Rectangle bounds) {
                // handle colour conversion?
                final MBFImage cimg = colourSpace.convert(image);

                // first band:
                dsift.analyseImage(cimg.bands.get(0), bounds);
                final int len = dsift.descriptors[0].length;
                descriptors = new float[dsift.descriptors.length][len * cimg.bands.size()];
                final float[][] tmpEnergies = new float[dsift.descriptors.length][cimg.bands.size()];

                for (int i = 0; i < descriptors.length; i++) {
                        System.arraycopy(dsift.descriptors[i], 0, descriptors[i], 0, len);
                        tmpEnergies[i][0] = dsift.energies[i];
                }

                // other bands
                for (int j = 1; j < cimg.bands.size(); j++) {
                        dsift.analyseImage(cimg.bands.get(j), bounds);
                        for (int i = 0; i < descriptors.length; i++) {
                                System.arraycopy(dsift.descriptors[i], 0, descriptors[i], j * len, len);
                                tmpEnergies[i][j] = dsift.energies[i];
                        }
                }

                // deal with energies
                energies = new float[descriptors.length];
                for (int i = 0; i < descriptors.length; i++) {
                        energies[i] = colourSpace.computeIntensity(tmpEnergies[i]);
                }
        }

        @Override
        public LocalFeatureList<FloatDSIFTKeypoint> getFloatKeypoints() {
                final MemoryLocalFeatureList<FloatDSIFTKeypoint> keys = new MemoryLocalFeatureList<FloatDSIFTKeypoint>(
                                dsift.numOriBins
                                                * dsift.numBinsX * dsift.numBinsY, descriptors.length);

                final int frameSizeX = dsift.binWidth * (dsift.numBinsX - 1) + 1;
                final int frameSizeY = dsift.binHeight * (dsift.numBinsY - 1) + 1;

                final float deltaCenterX = 0.5F * dsift.binWidth * (dsift.numBinsX - 1);
                final float deltaCenterY = 0.5F * dsift.binHeight * (dsift.numBinsY - 1);

                for (int framey = dsift.data.boundMinY, i = 0; framey <= dsift.data.boundMaxY - frameSizeY + 1; framey += dsift.stepY)
                {
                        for (int framex = dsift.data.boundMinX; framex <= dsift.data.boundMaxX - frameSizeX + 1; framex += dsift.stepX, i++)
                        {
                                keys.add(new FloatDSIFTKeypoint(framex + deltaCenterX, framey + deltaCenterY, descriptors[i], energies[i]));
                        }
                }

                return keys;
        }

        @Override
        public LocalFeatureList<ByteDSIFTKeypoint> getByteKeypoints() {
                final MemoryLocalFeatureList<ByteDSIFTKeypoint> keys = new MemoryLocalFeatureList<ByteDSIFTKeypoint>(
                                dsift.numOriBins
                                                * dsift.numBinsX * dsift.numBinsY, descriptors.length);

                final int frameSizeX = dsift.binWidth * (dsift.numBinsX - 1) + 1;
                final int frameSizeY = dsift.binHeight * (dsift.numBinsY - 1) + 1;

                final float deltaCenterX = 0.5F * dsift.binWidth * (dsift.numBinsX - 1);
                final float deltaCenterY = 0.5F * dsift.binHeight * (dsift.numBinsY - 1);

                for (int framey = dsift.data.boundMinY, i = 0; framey <= dsift.data.boundMaxY - frameSizeY + 1; framey += dsift.stepY)
                {
                        for (int framex = dsift.data.boundMinX; framex <= dsift.data.boundMaxX - frameSizeX + 1; framex += dsift.stepX, i++)
                        {
                                keys.add(new ByteDSIFTKeypoint(framex + deltaCenterX, framey + deltaCenterY, descriptors[i], energies[i]));
                        }
                }

                return keys;
        }

        @Override
        public LocalFeatureList<FloatDSIFTKeypoint> getFloatKeypoints(float energyThreshold) {
                final MemoryLocalFeatureList<FloatDSIFTKeypoint> keys = new MemoryLocalFeatureList<FloatDSIFTKeypoint>(
                                dsift.numOriBins
                                                * dsift.numBinsX * dsift.numBinsY);

                final int frameSizeX = dsift.binWidth * (dsift.numBinsX - 1) + 1;
                final int frameSizeY = dsift.binHeight * (dsift.numBinsY - 1) + 1;

                final float deltaCenterX = 0.5F * dsift.binWidth * (dsift.numBinsX - 1);
                final float deltaCenterY = 0.5F * dsift.binHeight * (dsift.numBinsY - 1);

                for (int framey = dsift.data.boundMinY, i = 0; framey <= dsift.data.boundMaxY - frameSizeY + 1; framey += dsift.stepY)
                {
                        for (int framex = dsift.data.boundMinX; framex <= dsift.data.boundMaxX - frameSizeX + 1; framex += dsift.stepX, i++)
                        {
                                if (energies[i] >= energyThreshold)
                                        keys.add(new FloatDSIFTKeypoint(framex + deltaCenterX, framey + deltaCenterY, descriptors[i],
                                                        energies[i]));
                        }
                }

                return keys;
        }

        @Override
        public LocalFeatureList<ByteDSIFTKeypoint> getByteKeypoints(float energyThreshold) {
                final MemoryLocalFeatureList<ByteDSIFTKeypoint> keys = new MemoryLocalFeatureList<ByteDSIFTKeypoint>(
                                dsift.numOriBins
                                                * dsift.numBinsX * dsift.numBinsY);

                final int frameSizeX = dsift.binWidth * (dsift.numBinsX - 1) + 1;
                final int frameSizeY = dsift.binHeight * (dsift.numBinsY - 1) + 1;

                final float deltaCenterX = 0.5F * dsift.binWidth * (dsift.numBinsX - 1);
                final float deltaCenterY = 0.5F * dsift.binHeight * (dsift.numBinsY - 1);

                for (int framey = dsift.data.boundMinY, i = 0; framey <= dsift.data.boundMaxY - frameSizeY + 1; framey += dsift.stepY)
                {
                        for (int framex = dsift.data.boundMinX; framex <= dsift.data.boundMaxX - frameSizeX + 1; framex += dsift.stepX, i++)
                        {
                                if (energies[i] >= energyThreshold)
                                        keys.add(new ByteDSIFTKeypoint(framex + deltaCenterX, framey + deltaCenterY, descriptors[i],
                                                        energies[i]));
                        }
                }

                return keys;
        }

        @Override
        public void setBinWidth(int size) {
                this.dsift.setBinWidth(size);
        }

        @Override
        public void setBinHeight(int size) {
                this.dsift.setBinHeight(size);
        }

        @Override
        public int getBinWidth() {
                // TODO Auto-generated method stub
                return 0;
        }

        @Override
        public int getBinHeight() {
                // TODO Auto-generated method stub
                return 0;
        }

        @Override
        public int getNumBinsX() {
                // TODO Auto-generated method stub
                return 0;
        }

        @Override
        public int getNumBinsY() {
                // TODO Auto-generated method stub
                return 0;
        }

        @Override
        public int getNumOriBins() {
                // TODO Auto-generated method stub
                return 0;
        }

        @Override
        public float[][] getDescriptors() {
                return descriptors;
        }
}