Application: gvSIG desktop

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2006 IVER T.I. and Generalitat Valenciana.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 */

package org.gvsig.raster.grid.filter.enhancement;

import org.gvsig.raster.buffer.RasterBuffer;

import org.gvsig.raster.dataset.IBuffer;

/**

 * Filtro de contraste para im?genes de 16 bits. En el m?todo de proceso 

 * procesa un solo pixel short. Varia su contraste en relaci?n a los par?metros

 * asignados en el m?todo pre();

 * 

 * @author Miguel ?ngel Querol Carratal? (miguelangel.querol@iver.es)

 *

 */

public class ContrastShortFilter extends ContrastFilter {

        protected IBuffer                rasterResult = null;

        /**

         * Constructor de Contraste para layers de tipo short

         */

        public ContrastShortFilter(){

                super();

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.grid.filter.enhancement.ContrastFilter#pre()

         */

        public void pre(){

                exec = true;

                this.raster = (RasterBuffer) params.get("raster");

                height = raster.getHeight();

                width = raster.getWidth();

                this.incrContraste = ((Integer) this.params.get("incrContraste")).shortValue();

                rasterResult = RasterBuffer.getBuffer(IBuffer.TYPE_SHORT, raster.getWidth(), raster.getHeight(), raster.getBandCount(), true);

                super.pre();

        }

        /**

         * Algoritmo de contraste

         * @param px3 valores ARGB

         * @return valores ARGB con el algoritmo aplicado

         */

        private short[] calcContrast(short[] px) {

                short result = 0;

                short diferencia;

                for (int i = 0; i < 3; i++) {

                        px[i] = (short) (px[i] % 256);

                        if (incrContraste >= 0) {

                                if (px[i] < 127) {

                                        diferencia = (short) (127 - px[i]);

                                        result = (short) (px[i] - (short) ((diferencia * 5) * (incrContraste * 0.1) / 25));

                                        if (result < 0)

                                                result = 0;

                                }

                                if (px[i] > 127) {

                                        diferencia = (short) (px[i] - 127);

                                        result = (short) (px[i] + (short) ((diferencia * 5) * (incrContraste * 0.1) / 25));

                                        if (result > 255)

                                                result = 255;

                                }

                        } else { // incrContraste < 0

                                if (px[i] < 127) {

                                        diferencia = (short) (127 - px[i]);

                                        result = (short) (px[i] + (diferencia * (short) (-incrContraste * 0.1) / 25));

                                        if (result > 127)

                                                result = 127;

                                        if (px[i] == 0 || px[i] == 0)

                                                if (incrContraste > -255)

                                                        result = 0;

                                }

                                if (px[i] > 127) {

                                        diferencia = (short) (px[i] - 127);

                                        result = (short) (px[i] - (diferencia * (short) (-incrContraste * 0.1) / 25));

                                        if (result < 127)

                                                result = 127;

                                        if (px[i] == 255 || px[i] == 254)

                                                if (incrContraste > -255)

                                                        result = 255;

                                }

                        }

                        px[i] = result;

                }

                return px;

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.grid.filter.enhancement.ContrastFilter#process(int, int)

         */

        public void process(int col, int line) {

                short[] px = new short[4];

                raster.getElemShort(line, col, px);

                px = calcContrast(px);

                rasterResult.setElemShort(line, col, px);

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.grid.filter.enhancement.ContrastFilter#getInRasterDataType()

         */

        public int getInRasterDataType() {

                return RasterBuffer.TYPE_SHORT;

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.grid.filter.enhancement.ContrastFilter#getOutRasterDataType()

         */

        public int getOutRasterDataType() {

                return RasterBuffer.TYPE_SHORT;

        }

        /*

         * (non-Javadoc)

         * @see org.gvsig.raster.grid.filter.enhancement.ContrastFilter#getResult(java.lang.String)

         */

        public Object getResult(String name) {

                if (name.equals("raster"))

                        return (Object) this.rasterResult;

                return null;

        }

}