/*
* Geotoolkit.org - An Open Source Java GIS Toolkit
* http://www.geotoolkit.org
*
* (C) 2005-2012, Open Source Geospatial Foundation (OSGeo)
* (C) 2009-2012, Geomatys
*
* 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotoolkit.coverage.processing.operation;
import javax.media.jai.operator.DivideByConstDescriptor;
import org.apache.sis.measure.NumberRange;
import org.geotoolkit.coverage.processing.OperationJAI;
/**
* Divides every sample values of the source coverage by constants (one for each band).
* If the number of constants supplied is less than the number of bands of the destination,
* then the constant from entry 0 is applied to all the bands. Otherwise, a constant from a
* different entry is applied to each band.
*
* <P><b>Name:</b> {@code "DivideByConst"}<BR>
* <b>JAI operator:</b> <CODE>"{@linkplain DivideByConstDescriptor DivideByConst}"</CODE><BR>
* <b>Parameters:</b></P>
* <table border='3' cellpadding='6' bgcolor='F4F8FF'>
* <tr bgcolor='#B9DCFF'>
* <th>Name</th>
* <th>Class</th>
* <th>Default value</th>
* <th>Minimum value</th>
* <th>Maximum value</th>
* </tr>
* <tr>
* <td>{@code "Source"}</td>
* <td>{@link org.geotoolkit.coverage.grid.GridCoverage2D}</td>
* <td align="center">N/A</td>
* <td align="center">N/A</td>
* <td align="center">N/A</td>
* </tr>
* <tr>
* <td>{@code "constants"}</td>
* <td>{@code double[]}</td>
* <td align="center">1.0</td>
* <td align="center">N/A</td>
* <td align="center">N/A</td>
* </tr>
* </table>
*
* @author Martin Desruisseaux (IRD)
* @version 3.00
*
* @see org.geotoolkit.coverage.processing.Operations#divideBy
* @see DivideByConstDescriptor
*
* @since 2.2
* @module
*
* @todo Should operates on {@code sampleToGeophysics} transform when possible.
* See <A HREF="http://jira.codehaus.org/browse/GEOT-610">GEOT-610</A>.
*/
public class DivideByConst extends OperationJAI {
/**
* Serial number for inter-operability with different versions.
*/
private static final long serialVersionUID = -3723238033407316564L;
/**
* Constructs a default {@code "DivideByConst"} operation.
*/
public DivideByConst() {
super("DivideByConst");
}
/**
* Returns the expected range of values for the resulting image.
*/
@Override
protected NumberRange<?> deriveRange(final NumberRange<?>[] ranges, final Parameters parameters) {
final double[] constants = (double[]) parameters.parameters.getObjectParameter("constants");
if (constants.length == 1) {
final double c = constants[0];
final NumberRange<?> range = ranges[0];
final double min = range.getMinDouble() / c;
final double max = range.getMaxDouble() / c;
return (max < min) ? NumberRange.create(max, true, min, true) : NumberRange.create(min, true, max, true);
}
return super.deriveRange(ranges, parameters);
}
}