ingo@1115: /*
ingo@1115:  * Copyright (c) 2010 by Intevation GmbH
ingo@1115:  *
ingo@1115:  * This program is free software under the LGPL (>=v2.1)
ingo@1115:  * Read the file LGPL.txt coming with the software for details
ingo@1115:  * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@1115:  */
ingo@1115: 
sascha@441: package de.intevation.gnv.raster;
sascha@441: 
sascha@779: import org.apache.log4j.Logger;
sascha@779: 
sascha@441: import org.w3c.dom.Element;
sascha@441: 
sascha@441: /**
sascha@801:  * An implemenation of raster filters based on given kernels.
sascha@780:  * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
sascha@441:  */
sascha@441: public class KernelFilter
sascha@441: implements   Filter
sascha@441: {
sascha@441:     private static Logger log = Logger.getLogger(KernelFilter.class);
sascha@441: 
sascha@801:     /**
sascha@801:      *  Implemens a factory which produces KernelFilters with Gauss kernels.
sascha@801:      */
sascha@441:     public static class GaussFactory
sascha@441:     implements          Filter.Factory
sascha@441:     {
sascha@801:         /**
sascha@801:          * Default sigma of Gauss kernel: {@value}
sascha@801:          */
sascha@441:         public static final double DEFAULT_SIGMA  = 1.0d;
sascha@801:         /**
sascha@801:          * Default radius of Gauss kernel: {@value}
sascha@801:          */
sascha@441:         public static final int    DEFAULT_RADIUS = 5;
sascha@441: 
sascha@801:         /**
sascha@801:          * Configured sigma.
sascha@801:          */
sascha@441:         protected double sigma;
sascha@801:         /**
sascha@801:          * Configured radius.
sascha@801:          */
sascha@441:         protected int    radius;
sascha@441: 
sascha@801:         /**
sascha@801:          * Default constructor.
sascha@801:          */
sascha@441:         public GaussFactory() {
sascha@441:             sigma  = DEFAULT_SIGMA;
sascha@441:             radius = DEFAULT_RADIUS;
sascha@441:         }
sascha@441: 
sascha@441:         public void init(Element element) {
sascha@441:             String s = element.getAttribute("sigma");
sascha@441:             String r = element.getAttribute("radius");
sascha@441: 
sascha@441:             if ((s = s.trim()).length() > 0) {
sascha@441:                 try {
sascha@441:                     sigma = Math.abs(Double.parseDouble(s));
sascha@441:                 }
sascha@441:                 catch (NumberFormatException nfe) {
sascha@441:                     log.warn("gauss sigma '" + s + "' not a valid float value.");
sascha@441:                 }
sascha@441:             }
sascha@441: 
sascha@441:             if ((r = r.trim()).length() > 0) {
sascha@441:                 try {
sascha@441:                     radius = Math.min(3, Math.abs(Integer.parseInt(r)));
sascha@441:                 }
sascha@441:                 catch (NumberFormatException nfe) {
sascha@441:                     log.warn("gauss radius '" + r + "' not a valid integer value.");
sascha@441:                 }
sascha@441:             }
sascha@441:         }
sascha@441: 
sascha@441:         public Filter create() {
sascha@441:             return new KernelFilter(Raster.Kernel.createGauss(sigma, radius));
sascha@441:         }
sascha@441:     } // class GaussFactory
sascha@441: 
sascha@801:     /**
sascha@801:      * The kernel used by this filter.
sascha@801:      */
sascha@441:     protected Raster.Kernel kernel;
sascha@441: 
sascha@801:     /**
sascha@801:      * Default constructor.
sascha@801:      */
sascha@441:     public KernelFilter() {
sascha@441:     }
sascha@441: 
sascha@801:     /**
sascha@801:      * Constructor to create a filter with a given kernel.
sascha@801:      * @param kernel The kernel to be used.
sascha@801:      */
sascha@441:     public KernelFilter(Raster.Kernel kernel) {
sascha@441:         this.kernel = kernel;
sascha@441:     }
sascha@441: 
sascha@441:     public Raster filter(Raster raster) {
sascha@441:         return raster.create(kernel);
sascha@441:     }
sascha@441: }
sascha@798: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :