/*
* 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.List;
import java.util.Map;
import java.util.logging.Logger;
import javax.media.jai.JAI;
import javax.media.jai.RenderedOp;
import javax.media.jai.operator.ExtremaDescriptor;
import org.geotools.coverage.grid.GridCoverage2D;
import org.geotools.coverage.processing.AbstractStatisticsOperationJAI;
import org.geotools.util.logging.Logging;
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 Extrema operations described by
* {@link ExtremaDescriptor} inside a GeoTools operation in order to make it
* spatial-aware.
*
* <p>
* 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.
*
* <p>
* For more information on how the underlying {@link JAI} operators works you
* can have a look here: <a
* href="http://download.java.net/media/jai/javadoc/1.1.3/jai-apidocs/javax/media/jai/operator/ExtremaDescriptor.html">ExtremaDescriptor</a>
*
* <p>
* <strong>How to use this operation</strong> Here is a very simple example on
* how to use this operation in order to the minimum and maximum of the source
* coverage.
*
* <code>
* final OperationJAI op=new OperationJAI("Extrema");
* ParameterValueGroup params = op.getParameters();
* params.parameter("Source").setValue(coverage);
* coverage=(GridCoverage2D) op.doOperation(params,null);
* System.out.println(((double[])coverage.getProperty("minimum"))[0]);
* System.out.println(((double[])coverage.getProperty("minimum"))[1]);
* System.out.println(((double[])coverage.getProperty("minimum"))[2]);
* System.out.println(((double[])coverage.getProperty("maximum"))[0]);
* System.out.println(((double[])coverage.getProperty("maximum"))[1]);
* System.out.println(((double[])coverage.getProperty("maximum"))[2]);
* </code>
*
* @author Simone Giannecchini
* @since 2.4
*
*
*
* @source $URL$
*/
public class Extrema extends AbstractStatisticsOperationJAI {
/**
* Serial number for interoperability with different versions.
*/
private static final long serialVersionUID = 7731039381590398047L;
/** {@link Logger} for this class. */
public final static Logger LOGGER = Logging.getLogger("org.geotools.coverage.processing.operation");
/** {@link String} key for getting the minimum vector. */
public final static String GT_SYNTHETIC_PROPERTY_MINIMUM = "minimum";
/** {@link String} key for getting the maximum vector. */
public final static String GT_SYNTHETIC_PROPERTY_MAXIMUM = "maximum";
/**Locations of min values. */
public final static String GT_SYNTHETIC_PROPERTY_MIN_LOCATIONS="minLocations";
/**Locations of max values. */
public final static String GT_SYNTHETIC_PROPERTY_MAX_LOCATIONS="maxLocations";
/**
* Constructs a default {@code "Extrema"} operation.
*/
public Extrema() throws OperationNotFoundException {
super(getOperationDescriptor("Extrema"));
}
/**
* 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 minimum and maximum properties for this extream operation.
*
* <p>
* See <a
* href="http://download.java.net/media/jai/javadoc/1.1.3/jai-apidocs/javax/media/jai/operator/ExtremaDescriptor.html">ExtremaDescriptor</a>
* for more info.
*
* @see OperationJAI#getProperties(RenderedImage, CoordinateReferenceSystem,
* InternationalString, MathTransform, GridCoverage2D[],
* org.geotools.coverage.processing.OperationJAI.Parameters),
*/
@SuppressWarnings("unchecked")
protected Map<String,?> getProperties(RenderedImage data,
CoordinateReferenceSystem crs, InternationalString name,
MathTransform toCRS, GridCoverage2D[] sources, Parameters parameters) {
// /////////////////////////////////////////////////////////////////////
//
// If and only if data is a RenderedOp we prepare the properties for
// minimum and maximum as the output of the extrema operation.
//
// /////////////////////////////////////////////////////////////////////
if (data instanceof RenderedOp) {
final RenderedOp result = (RenderedOp) data;
final Map<String, Object> synthProp = new HashMap<String, Object>();
// get the properties
final double[] maximums = (double[]) result
.getProperty(GT_SYNTHETIC_PROPERTY_MAXIMUM);
final double[] minimums = (double[]) result
.getProperty(GT_SYNTHETIC_PROPERTY_MINIMUM);
Object property=result.getProperty(GT_SYNTHETIC_PROPERTY_MIN_LOCATIONS);
if((property instanceof List[]))
synthProp.put(GT_SYNTHETIC_PROPERTY_MIN_LOCATIONS, (List<int[]>[])property);
property=result.getProperty(GT_SYNTHETIC_PROPERTY_MAX_LOCATIONS);
if((property instanceof List[]))
synthProp.put(GT_SYNTHETIC_PROPERTY_MAX_LOCATIONS, (List<int[]>[])property);
// return the map
synthProp.put(GT_SYNTHETIC_PROPERTY_MINIMUM, minimums);
synthProp.put(GT_SYNTHETIC_PROPERTY_MAXIMUM, maximums);
return Collections.unmodifiableMap(synthProp);
}
return super.getProperties(data, crs, name, toCRS, sources, parameters);
}
}