Application: gvSIG desktop » gvSIG raster

/* gvSIG. Geographic Information System of the Valencian Government

 *

 * Copyright (C) 2007-2008 Infrastructures and Transports Department

 * of the Valencian Government (CIT)

 *

 * 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., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 */

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

import org.gvsig.fmap.dal.coverage.dataset.Buffer;

import org.gvsig.raster.impl.datastruct.DefaultStretch;

/**

 * Filtro de realce lineal para tipos de datos byte. El realce es aplicado por intervalos.

 * Para cada pixel se obtiene en que intervalo se encuentra y se aplica la scala y offset

 * calculados para ese intervalo.

 *

 * @author Nacho Brodin (nachobrodin@gmail.com)

 */

public class LinearStretchEnhancementByteFilter extends LinearStretchEnhancementFilter {

        public void process(int col, int line) {

                for (int iBand = 0; iBand < numberOfBandsToProcess(); iBand++) {

                        int p;

                        if (stretchs.rgb)

                                p = (int) (raster.getElemByte(line, col, iBand) & 0xff);

                        else

                                p = (int) raster.getElemByte(line, col, iBand);

                        if (iBand < scaleOffsetList.length)

                                processValue(p, scaleOffsetList[iBand], col, line, iBand);

                        else

                                rasterResult.setElem(line, col, iBand, (byte) p);

                }

                writeAlphaBand(line, col);

        }

        /**

         * Procesa un dato del raster aplicandole el factor de escala y desplazamiento que

         * necesita.

         * @param p Valor del punto

         * @param data Estructura de datos con los valores de escala y desplazamiento

         * @param col Columna del valor dentro del raster

         * @param line L?nea del valor dentro del raster

         * @param iBand N?mero de banda del valor dentro del raster

         * @return true si ha podido ser procesado y false si no lo hace

         */

        private void processValue(int p, DefaultStretch data, int col, int line, int iBand) {

                if(data.scale != null) {

                        if (p > data.maxValue)

                                p = (int) data.maxValue;

                        else if (p < data.minValue)

                                p = (int) data.minValue;

                        for (int i = 0; i < data.scale.length; i++) {

                                if((p > data.stretchIn[i] && p <= data.stretchIn[i + 1]) || (i == 0 && p == data.stretchIn[i])) {

                                        p =  (int)( (((double)p) - data.stretchIn[i]) * data.scale[i] + data.offset[i]);

                                        break;

                                }

                        }

                        rasterResult.setElem(line, col, iBand, (byte)p);

                }

        }

        public int getInRasterDataType() {

                return Buffer.TYPE_BYTE;

        }

}