/**
 * 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
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.image.segmentation;

import org.openimaj.feature.FloatFVComparator;
import org.openimaj.image.MBFImage;
import org.openimaj.image.colour.ColourSpace;

/**
 * Simple image segmentation from grouping colours with k-means, and also
 * incorporating a spatial aspect based on pixel location.
 * 
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 * 
 */
public class KMSpatialColourSegmenter extends KMColourSegmenter {

        /**
         * Construct using the given colour space and number of segments. Euclidean
         * distance is used, and the elements of each colour band are unscaled. Up
         * to 100 K-Means iterations will be performed.
         * 
         * @param colourSpace
         *            the colour space
         * @param K
         *            the number of segments
         */
        public KMSpatialColourSegmenter(ColourSpace colourSpace, int K) {
                super(colourSpace, K);
        }

        /**
         * Construct using the given colour space, number of segments, and distance
         * measure. The elements of each colour band are unscaled. Up to 100 K-Means
         * iterations will be performed.
         * 
         * @param colourSpace
         *            the colour space
         * @param K
         *            the number of segments
         * @param distance
         *            the distance measure
         */
        public KMSpatialColourSegmenter(ColourSpace colourSpace, int K, FloatFVComparator distance) {
                super(colourSpace, K, distance);
        }

        /**
         * Construct using the given colour space, number of segments, and distance
         * measure. The elements of each colour band are by the corresponding
         * elements in the given scaling vector; the scaling vector should be two
         * elements longer than the number of colour bands of the target colour
         * space such that the last two elements correspond to the scalings for the
         * normalised x and y positions of the pixels. Up to 100 K-Means iterations
         * will be performed.
         * 
         * @param colourSpace
         *            the colour space
         * @param scaling
         *            the scaling vector
         * @param K
         *            the number of segments
         * @param distance
         *            the distance measure
         */
        public KMSpatialColourSegmenter(ColourSpace colourSpace, float[] scaling, int K, FloatFVComparator distance) {
                super(colourSpace, scaling, K, distance);
        }

        /**
         * Construct using the given colour space, number of segments, and distance
         * measure. The elements of each colour band are by the corresponding
         * elements in the given scaling vector; the scaling vector should be two
         * elements longer than the number of colour bands of the target colour
         * space such that the last two elements correspond to the scalings for the
         * normalised x and y positions of the pixels. The k-means algorithm will
         * iterate at most <code>maxIters</code> times.
         * 
         * @param colourSpace
         *            the colour space
         * @param scaling
         *            the scaling vector
         * @param K
         *            the number of segments
         * @param distance
         *            the distance measure
         * @param maxIters
         *            the maximum number of iterations to perform
         */
        public KMSpatialColourSegmenter(ColourSpace colourSpace, float[] scaling, int K, FloatFVComparator distance,
                        int maxIters)
        {
                super(colourSpace, scaling, K, distance, maxIters);
        }

        @Override
        protected float[][] imageToVector(MBFImage image) {
                final int height = image.getHeight();
                final int width = image.getWidth();
                final int bands = image.numBands();

                final float[][] f = new float[height * width][bands + 2];
                for (int b = 0; b < bands; b++) {
                        final float[][] band = image.getBand(b).pixels;
                        final float w = scaling == null ? 1 : scaling[b];

                        for (int y = 0; y < height; y++)
                                for (int x = 0; x < width; x++)
                                        f[x + y * width][b] = band[y][x] * w;
                }
                for (int y = 0; y < height; y++) {
                        for (int x = 0; x < width; x++) {
                                f[x + y * width][bands] = ((float) x / (float) width) * (scaling == null ? 1 : scaling[bands]);
                                f[x + y * width][bands + 1] = ((float) y / (float) height) * (scaling == null ? 1 : scaling[bands + 1]);
                        }
                }

                return f;
        }
}