// Catalano Imaging Library
// The Catalano Framework
//
// Copyright © Diego Catalano, 2012-2016
// diego.catalano at live.com
//
//    This library is free software; you can redistribute it and/or
//    modify it under the terms of the GNU Lesser General Public
//    License as published by the Free Software Foundation; either
//    version 2.1 of the License, or (at your option) any later version.
//
//    This library is distributed in the hope that it will be useful,
//    but WITHOUT ANY WARRANTY; without even the implied warranty of
//    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//    Lesser General Public License for more details.
//
//    You should have received a copy of the GNU Lesser General Public
//    License along with this library; if not, write to the Free Software
//    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
//

package Catalano.Imaging.Filters;

import Catalano.Imaging.FastBitmap;
import Catalano.Imaging.IApplyInPlace;

/**
 * Morphologic Gradient Image.
 * 
 *  In mathematical morphology and digital image processing, a morphological gradient is the
 * difference between the dilation and the erosion of a given image.
 * It is an image where each pixel value (typically non-negative) indicates the contrast intensity in the
 * close neighborhood of that pixel. It is useful for edge detection and segmentation applications.
 * 
 * References: http://en.wikipedia.org/wiki/Morphological_gradient
 * 
 * @author Diego Catalano
 */
public class MorphologicGradientImage implements IApplyInPlace{
    
    private int[][] kernel;
    private int radius = 1;
    private boolean applyRadius = true;

    /**
     * Get Radius of morphologic operators.
     * @return Radius.
     */
    public int getRadius() {
        return radius;
    }

    /**
     * Set Radius of morphologic operators.
     * @param radius Radius.
     */
    public void setRadius(int radius) {
        this.radius = radius;
        this.applyRadius = true;
    }

    /**
     * Get Kernel of morphologic operators.
     * @return Kernel.
     */
    public int[][] getKernel() {
        return kernel;
    }

    /**
     * Set Kernel of morphologic operators.
     * @param kernel Kernel.
     */
    public void setKernel(int[][] kernel) {
        this.kernel = kernel;
        this.applyRadius = false;
    }

    /**
     * Initialize a new instance of the MorphologicGradientImage class.
     */
    public MorphologicGradientImage() {}
    
    /**
     * Initialize a new instance of the MorphologicGradientImage class.
     * @param radius Radius.
     */
    public MorphologicGradientImage(int radius){
        this.radius = radius;
        this.applyRadius = true;
    }
    
    /**
     * Initialize a new instance of the MorphologicGradientImage class.
     * @param kernel Kernel.
     */
    public MorphologicGradientImage(int[][] kernel){
        this.kernel = kernel;
        this.applyRadius = false;
    }

    @Override
    public void applyInPlace(FastBitmap fastBitmap) {
        
        if (fastBitmap.isGrayscale()){
            FastBitmap temp = new FastBitmap(fastBitmap);
            
            if (applyRadius){
                Dilatation dil = new Dilatation(radius);
                dil.applyInPlace(fastBitmap);

                Erosion ero = new Erosion(radius);
                ero.applyInPlace(temp);
            }
            else{
                Dilatation dil = new Dilatation(kernel);
                dil.applyInPlace(fastBitmap);

                Erosion ero = new Erosion(kernel);
                ero.applyInPlace(temp);
            }
            
            Subtract sub = new Subtract(temp);
            sub.applyInPlace(fastBitmap);
        }
        else{
            throw new IllegalArgumentException("Morphologic Gradient Image only works with grayscale images.");
        }
    }
}