/**
 * 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
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.openimaj.image.pixel.statistics;

import org.openimaj.image.FImage;
import org.openimaj.image.MBFImage;

/**
 * A multidimensional histogram calculated from image pixels selected through a mask
 * (assumes image is in 0-1 range)
 * 
 * @author Jonathon Hare
 *
 */
public class MaskingHistogramModel extends HistogramModel {
        private static final long serialVersionUID = 1L;
        private FImage mask;

        /**
         * Construct with the given parameters
         * @param mask the mask image
         * @param nbins the number of bins in each dimension for the histograms
         */
        public MaskingHistogramModel(FImage mask, int... nbins) {
                super(nbins);
                
                this.mask = mask;
        }
        
        @Override
        protected void accum(MBFImage im) {
                if (im.numBands() != ndims)
                        throw new AssertionError("number of bands must match");
                
                for (int y=0; y<im.getHeight(); y++) {
                        for (int x=0; x<im.getWidth(); x++) {
                                if (mask.pixels[y][x] != 1)
                                        continue;
                                
                                int [] bins = new int[ndims];
                                
                                for (int i=0; i<ndims; i++) {
                                        bins[i] = (int)(im.getBand(i).pixels[y][x] * (histogram.nbins[i]));
                                        if (bins[i] >= histogram.nbins[i]) bins[i] = histogram.nbins[i] - 1;
                                }
                                
                                int bin = 0;
                                for (int i=0; i<ndims; i++) {
                                        int f = 1;
                                        for (int j=0; j<i; j++)
                                                f *= histogram.nbins[j];
                                        
                                        bin += f * bins[i];
                                }
                                
                                histogram.values[bin]++;
                        }
                }
        }
}