/* * GeoTools - The Open Source Java GIS Toolkit * http://geotools.org * * (C) 2005-2008, Open Source Geospatial Foundation (OSGeo) * * 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.geotools.coverage.processing.operation; import java.awt.Shape; import java.awt.image.RenderedImage; import java.util.Collections; import java.util.HashMap; import java.util.Map; import javax.media.jai.JAI; import javax.media.jai.RenderedOp; import javax.media.jai.operator.HistogramDescriptor; import org.geotools.coverage.grid.GridCoverage2D; import org.geotools.coverage.processing.AbstractStatisticsOperationJAI; import org.opengis.coverage.processing.OperationNotFoundException; import org.opengis.parameter.ParameterValueGroup; import org.opengis.referencing.crs.CoordinateReferenceSystem; import org.opengis.referencing.operation.MathTransform; import org.opengis.util.InternationalString; /** * * This operation simply wraps JAI Histogram operations described by * {@link HistogramDescriptor} inside a GeoTools operation in order to make it * spatial-aware. * *
* For the moment this is a very simple wrap. Plans on the 2.4 and successive * versions of this operation are to add the ability to use spatial ROIs and * to specific Spatial subsampling. As of now, ROI has to be a Java2D * {@link Shape} subclass and the parameters to control x and y subsamplings got * to be Integer, which means pixel-aware. * *
* For more information on how the underlying {@link JAI} operators works you
* can have a look here: HistogramDescriptor
*
*
* @author Simone Giannecchini
* @since 2.4
* @see javax.media.jai.Histogram
*
*
*
*
* @source $URL$
*/
public class Histogram extends AbstractStatisticsOperationJAI {
/**
* Serial number for interoperability with different versions.
*/
private static final long serialVersionUID = -4256576399698278701L;
/**
* {@link String} key for getting the {@link javax.media.jai.Histogram}
* object.
*/
public final static String GT_SYNTHETIC_PROPERTY_HISTOGRAM = "histogram";
/**
* Default constructor for the {@link Histogram} operation.
*
* @throws OperationNotFoundException
*/
public Histogram() throws OperationNotFoundException {
super(getOperationDescriptor("Histogram"));
}
/**
* This operation MUST be performed on the geophysics data for this
* {@link GridCoverage2D}.
*
* @param parameters
* {@link ParameterValueGroup} that describes this operation
* @return always true.
*/
protected boolean computeOnGeophysicsValues(ParameterValueGroup parameters) {
return true;
}
/**
* Prepare the {@link javax.media.jai.Histogram} property for this histogram
* operation.
*
*
* See HistogramDescriptor
* for more info.
*
* @see OperationJAI#getProperties(RenderedImage, CoordinateReferenceSystem,
* InternationalString, MathTransform, GridCoverage2D[],
* org.geotools.coverage.processing.OperationJAI.Parameters),
*/
protected Map