/**
 * 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.feature.local.detector.mser;

import java.util.ArrayList;
import java.util.List;

import org.openimaj.citation.annotation.Reference;
import org.openimaj.citation.annotation.ReferenceType;
import org.openimaj.image.FImage;
import org.openimaj.image.analysis.watershed.Component;
import org.openimaj.image.analysis.watershed.MergeTreeBuilder;
import org.openimaj.image.analysis.watershed.WatershedProcessor;
import org.openimaj.image.analysis.watershed.feature.ComponentFeature;
import org.openimaj.util.tree.TreeNode;

/**
 * Detector for MSER features.
 * 
 * @author David Dupplaw (dpd@ecs.soton.ac.uk)
 */
@Reference(
                type = ReferenceType.Article,
                author = { "J Matas", "O Chum", "M Urban", "T Pajdla" },
                title = "Robust wide-baseline stereo from maximally stable extremal regions",
                year = "2004",
                journal = "Image and Vision Computing",
                pages = { "761 ", " 767" },
                url = "http://www.sciencedirect.com/science/article/pii/S0262885604000435",
                number = "10",
                volume = "22",
                customData = {
                                "issn", "0262-8856",
                                "doi", "10.1016/j.imavis.2004.02.006",
                                "keywords", "Robust metric"
                })
public class MSERFeatureGenerator {
        /**
         * A way of representing how the MSER should be processed.
         * 
         * @author David Dupplaw (dpd@ecs.soton.ac.uk)
         * 
         */
        public enum MSERDirection {
                /**
                 * Upwards detection
                 */
                Up,
                /**
                 * Downwards detection
                 */
                Down,
                /**
                 * Upwards and Downwards detection
                 */
                UpAndDown
        }

        private int delta = 10;
        private int maxArea = Integer.MAX_VALUE;
        private int minArea = 1;
        private float maxVariation = Float.MAX_VALUE;
        private float minDiversity = 0;
        private Class<? extends ComponentFeature>[] featureClasses;

        /**
         * Default constructor
         * 
         * @param featureClasses
         *            features to generate for each mser
         */
        public MSERFeatureGenerator(Class<? extends ComponentFeature>... featureClasses) {
                this.featureClasses = featureClasses;
        }

        /**
         * Constructor that takes all the parameters for the MSER process.
         * 
         * @param delta
         * @param maxArea
         * @param minArea
         * @param maxVariation
         * @param minDiversity
         * @param featureClasses
         *            features to generate for each mser
         */
        public MSERFeatureGenerator(int delta, int maxArea, int minArea, float maxVariation, float minDiversity,
                        Class<? extends ComponentFeature>... featureClasses)
        {
                this(featureClasses);

                this.delta = delta;
                this.maxArea = maxArea;
                this.minArea = minArea;
                this.maxVariation = maxVariation;
                this.minDiversity = minDiversity;
        }

        /**
         * Performs a watershed then an MSER detection on the given image and
         * returns the MSERs.
         * 
         * @param img
         *            The image to analyse.
         * @return A list of {@link Component}s
         */
        public List<Component> generateMSERs(FImage img) {
                return generateMSERs(img, MSERDirection.UpAndDown);
        }

        /**
         * Performs a watershed then an MSER detection on the given image and
         * returns the MSERs.
         * 
         * @param img
         *            The image to analyse.#
         * @param dir
         *            The direction which to process the MSERS
         * @return A list of {@link Component}s
         */
        public List<Component> generateMSERs(FImage img, MSERDirection dir) {
                final List<MergeTreeBuilder> mtb = performWatershed(img);
                final List<Component> regions = performMSERDetection(mtb, dir);
                return regions;
        }

        /**
         * Perform the watershed algorithm on the given image.
         * 
         * @param img
         *            The image to perform the watershed on
         * @return A tuple of {@link MergeTreeBuilder}s (down first, up second)
         */
        public List<MergeTreeBuilder> performWatershed(FImage img) {
                // Create the image analysis object
                final WatershedProcessor watershedUp = new WatershedProcessor(featureClasses);
                final WatershedProcessor watershedDown = new WatershedProcessor(featureClasses);
                final MergeTreeBuilder treeBuilderUp = new MergeTreeBuilder();
                watershedUp.addComponentStackMergeListener(treeBuilderUp);
                final MergeTreeBuilder treeBuilderDown = new MergeTreeBuilder();
                watershedDown.addComponentStackMergeListener(treeBuilderDown);

                // -----------------------------------------------------------------
                // Watershed the image to get the tree
                // -----------------------------------------------------------------
                // bottom-up watershed
                watershedUp.processImage(img);

                // Invert the image, as we must detect MSERs from both top-down
                // and bottom-up.
                img = img.inverse();
                // top-down watershed
                watershedDown.processImage(img);

                // Return the image to its original state.
                img = img.inverse();

                final List<MergeTreeBuilder> mtb = new ArrayList<MergeTreeBuilder>();
                mtb.add(treeBuilderDown);
                mtb.add(treeBuilderUp);
                return mtb;
        }

        /**
         * Performs MSER detection on the trees provided. The input list must be a
         * list containing {@link MergeTreeBuilder}s, the first being the downward
         * watershed, the second being the upward watershed.
         * 
         * @param mtbs
         *            The list of {@link MergeTreeBuilder}s
         * @param dir
         *            The direction to detect MSERs from
         * @return A list of {@link Component}s
         */
        public List<Component> performMSERDetection(List<MergeTreeBuilder> mtbs, MSERDirection dir) {
                // Remove the MSER component flags in the trees (in case they're being
                // reused)
                clearTree(mtbs.get(0).getTree());
                clearTree(mtbs.get(1).getTree());

                // -----------------------------------------------------------------
                // Now run the MSER detector on it
                // -----------------------------------------------------------------
                // bottom up detection
                // System.out.println( mtbs.get(1).getTree() );
                List<Component> regionsUp = null;
                if (mtbs.get(1).getTree() != null && (dir == MSERDirection.Up || dir == MSERDirection.UpAndDown)) {
                        final MSERDetector mser = new MSERDetector(mtbs.get(1).getTree());
                        mser.setDelta(this.delta);
                        mser.setMaxArea(this.maxArea);
                        mser.setMinArea(this.minArea);
                        mser.setMaxVariation(this.maxVariation);
                        mser.setMinDiversity(this.minDiversity);
                        regionsUp = mser.detect();
                        // System.out.println( "Top-down detected: "+regionsUp );
                }

                // top-down detection
                List<Component> regionsDown = null;
                if (mtbs.get(0).getTree() != null && (dir == MSERDirection.Down || dir == MSERDirection.UpAndDown)) {
                        final MSERDetector mser2 = new MSERDetector(mtbs.get(0).getTree());
                        mser2.setDelta(this.delta);
                        mser2.setMaxArea(this.maxArea);
                        mser2.setMinArea(this.minArea);
                        mser2.setMaxVariation(this.maxVariation);
                        mser2.setMinDiversity(this.minDiversity);
                        regionsDown = mser2.detect();
                        // System.out.println( "Bottom-up detected: "+regionsDown );
                }

                final List<Component> regions = new ArrayList<Component>();
                if (regionsUp != null)
                        regions.addAll(regionsUp);
                if (regionsDown != null)
                        regions.addAll(regionsDown);

                // System.out.println( "Detected "+regions.size()+" regions ");
                // System.out.println( "Detected "+countMSERs( mtbs.get(0).getTree()
                // )+" in down tree" );
                // System.out.println( "Detected "+countMSERs( mtbs.get(1).getTree()
                // )+" in up tree" );
                return regions;
        }

        /**
         * Removes all the MSER flags from the components in the tree
         * 
         * @param tree
         *            The tree to clear MSER flags
         */
        private void clearTree(TreeNode<Component> tree) {
                if (tree == null)
                        return;
                final Component c = tree.getValue();
                if (c != null)
                        c.isMSER = false;
                if (tree.getChildren() != null)
                        for (final TreeNode<Component> child : tree.getChildren())
                                clearTree(child);
        }

        /**
         * Returns a count of the number of components in the tree that are marked
         * as MSERs.
         * 
         * @param tree
         *            The tree to count MSERs in
         * @return the count
         */
        public int countMSERs(TreeNode<Component> tree) {
                if (tree == null)
                        return 0;
                int retVal = 0;
                final Component c = tree.getValue();
                if (c != null && c.isMSER)
                        retVal++;
                if (tree.getChildren() != null)
                        for (final TreeNode<Component> child : tree.getChildren())
                                retVal += countMSERs(child);
                return retVal;

        }

        /**
         * @return the delta
         */
        public int getDelta() {
                return delta;
        }

        /**
         * @param delta
         *            the delta to set
         */
        public void setDelta(int delta) {
                this.delta = delta;
        }

        /**
         * @return the maxArea
         */
        public int getMaxArea() {
                return maxArea;
        }

        /**
         * @param maxArea
         *            the maxArea to set
         */
        public void setMaxArea(int maxArea) {
                this.maxArea = maxArea;
        }

        /**
         * @return the minArea
         */
        public int getMinArea() {
                return minArea;
        }

        /**
         * @param minArea
         *            the minArea to set
         */
        public void setMinArea(int minArea) {
                this.minArea = minArea;
        }

        /**
         * @return the maxVariation
         */
        public float getMaxVariation() {
                return maxVariation;
        }

        /**
         * @param maxVariation
         *            the maxVariation to set
         */
        public void setMaxVariation(float maxVariation) {
                this.maxVariation = maxVariation;
        }

        /**
         * @return the minDiversity
         */
        public float getMinDiversity() {
                return minDiversity;
        }

        /**
         * @param minDiversity
         *            the minDiversity to set
         */
        public void setMinDiversity(float minDiversity) {
                this.minDiversity = minDiversity;
        }

}