/*
* 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;
import java.awt.geom.AffineTransform;
import java.awt.image.DataBuffer;
import java.awt.image.WritableRaster;
import javax.media.jai.RasterFactory;
import org.opengis.geometry.Envelope;
import org.opengis.parameter.ParameterValueGroup;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.geotools.coverage.CoverageFactoryFinder;
import org.geotools.coverage.grid.GridCoverage2D;
import org.geotools.coverage.grid.GridCoverageFactory;
import org.geotools.coverage.processing.operation.Extrema;
import org.geotools.coverage.processing.operation.Histogram;
import org.geotools.geometry.Envelope2D;
import org.geotools.referencing.crs.DefaultGeographicCRS;
import org.geotools.referencing.operation.matrix.XAffineTransform;
import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.geom.LinearRing;
import com.vividsolutions.jts.geom.Polygon;
import com.vividsolutions.jts.geom.PrecisionModel;
import org.junit.*;
import static org.junit.Assert.*;
/**
* Testing Extrema and {@link Histogram} operations.
*
* @author Simone Giannecchini (GeoSolutions)
* @author Martin Desruisseaux (Geomatys)
*
*
* @source $URL$
*/
public final class StatisticsOperationsTest extends GridProcessingTestBase {
/**
* Creates a raster of the given type. Because we use only one tile with one band, the
* code below is pretty similar to the code we would have if we were just setting the
* values in a matrix.
*/
private static GridCoverage2D createRaster(final int type) {
final int width = 500;
final int height = 500;
final WritableRaster raster = RasterFactory.createBandedRaster(type, width, height, 1, null);
for (int y=0; y<height; y++) {
for (int x=0; x<width; x++) {
// We exploit the clamping capabilities of the sample model.
raster.setSample(x, y, 0, x + y);
}
}
final CoordinateReferenceSystem crs = DefaultGeographicCRS.WGS84;
final Envelope envelope = new Envelope2D(crs, 0, 0, 30, 30);
final GridCoverageFactory factory = CoverageFactoryFinder.getGridCoverageFactory(null);
return factory.create("My grayscale float coverage", raster, envelope);
}
/**
* Tests the "Extrema" operation with a raster of floating point values.
* This test compare the operation results with the expected ones using
* different subsampling values.
*/
@Test
public void testExtrema() {
final GridCoverage2D sampleFloatCoverage = createRaster(DataBuffer.TYPE_FLOAT);
assertEquals(DataBuffer.TYPE_FLOAT, sampleFloatCoverage.getRenderedImage().getSampleModel().getDataType());
final AffineTransform gridToCRS = getAffineTransform(sampleFloatCoverage);
assertNotNull(gridToCRS);
/*
* Create the ROI as a JTS polygon.
*/
final PrecisionModel pm = new PrecisionModel();
final GeometryFactory gf = new GeometryFactory(pm, 0);
final Envelope2D envelope = sampleFloatCoverage.getEnvelope2D();
final double minX = envelope.getMinX();
final double minY = envelope.getMinY();
final double maxX = envelope.getCenterX();
final double maxY = envelope.getCenterY();
final Coordinate[] corners = new Coordinate[] {
new Coordinate(minX, minY),
new Coordinate(maxX, minY),
new Coordinate(maxX, maxY),
new Coordinate(minX, maxY),
new Coordinate(minX, minY)
};
final LinearRing ring = gf.createLinearRing(corners);
final Polygon roi = new Polygon(ring, null, gf);
/*
* Create the operation for the Extrema with a ROI.
* No subsampling should be applied.
*/
final CoverageProcessor processor = CoverageProcessor.getInstance();
final AbstractOperation op = (AbstractOperation) processor.getOperation("Extrema");
assertTrue(op instanceof Extrema);
final ParameterValueGroup params = op.getParameters();
params.parameter("Source") .setValue(sampleFloatCoverage);
params.parameter("xPeriod").setValue(1 * XAffineTransform.getScaleX0(gridToCRS));
params.parameter("yPeriod").setValue(1 * XAffineTransform.getScaleY0(gridToCRS));
params.parameter("roi").setValue(roi);
GridCoverage2D coverage = (GridCoverage2D) op.doOperation(params, null);
double[] minimum = (double[]) coverage.getProperty("minimum");
double[] maximum = (double[]) coverage.getProperty("maximum");
assertEquals(1, minimum.length);
assertEquals(1, maximum.length);
assertEquals(250.0, minimum[0], 0);
assertEquals(748.0, maximum[0], 0);
/*
* Create the operation for the Extrema with a ROI and subsampling by 2. The
* source and the ROI are left unchanged. The maximal value is expected to be
* slightly different than the above test because of the change in subsampling.
*/
params.parameter("xPeriod").setValue(2 * XAffineTransform.getScaleX0(gridToCRS));
params.parameter("yPeriod").setValue(2 * XAffineTransform.getScaleY0(gridToCRS));
coverage = (GridCoverage2D) op.doOperation(params, null);
minimum = (double[]) coverage.getProperty("minimum");
maximum = (double[]) coverage.getProperty("maximum");
assertEquals(1, minimum.length);
assertEquals(1, maximum.length);
assertEquals(250.0, minimum[0], 0);
assertEquals(746.0, maximum[0], 0);
}
/**
* Tests the "Histogram" operation with a raster of byte values.
* This test compare the operation results with the expected ones
* using different subsampling values.
*/
@Test
public void testHistogram() {
final GridCoverage2D sampleByteCoverage = createRaster(DataBuffer.TYPE_BYTE );
assertEquals(DataBuffer.TYPE_BYTE, sampleByteCoverage .getRenderedImage().getSampleModel().getDataType());
final AffineTransform gridToCRS = getAffineTransform(sampleByteCoverage);
assertNotNull(gridToCRS);
/*
* Create the ROI as a JTS polygon.
*/
final PrecisionModel pm = new PrecisionModel();
final GeometryFactory gf = new GeometryFactory(pm, 0);
final Envelope2D envelope = sampleByteCoverage.getEnvelope2D();
final double minX = envelope.getMinX();
final double maxY = envelope.getMaxY();
final double minY = maxY - envelope.getHeight() / 16;
final double maxX = minX + envelope.getWidth() / 16;
final Coordinate[] coord = new Coordinate[] {
new Coordinate(minX, maxY),
new Coordinate(maxX, maxY),
new Coordinate(maxX, minY),
new Coordinate(minX, minY),
new Coordinate(minX, maxY)
};
final LinearRing ring = gf.createLinearRing(coord);
final Polygon roi = new Polygon(ring, null, gf);
/*
* Create the operation for the Histogram with a ROI.
* No subsampling should be applied.
*/
final CoverageProcessor processor = CoverageProcessor.getInstance();
final AbstractOperation op = (AbstractOperation) processor.getOperation("Histogram");
assertTrue(op instanceof Histogram);
final ParameterValueGroup params = op.getParameters();
params.parameter("Source").setValue(sampleByteCoverage);
params.parameter("xPeriod").setValue(1 * XAffineTransform.getScaleX0(gridToCRS));
params.parameter("yPeriod").setValue(1 * XAffineTransform.getScaleY0(gridToCRS));
params.parameter("roi").setValue(roi);
GridCoverage2D coverage = (GridCoverage2D) op.doOperation(params, null);
javax.media.jai.Histogram histogram = (javax.media.jai.Histogram) coverage
.getProperty(Histogram.GT_SYNTHETIC_PROPERTY_HISTOGRAM);
assertEquals(0, histogram.getBinSize(0, 255));
assertEquals(1, histogram.getBinSize(0, 60));
/*
* Create the operation for the Histogram with a ROI and subsampling by 7. The
* source and the ROI are left unchanged. The histogram values are expected to
* be slightly different than the above test because of the change in subsampling.
*/
params.parameter("xPeriod").setValue(7 * XAffineTransform.getScaleX0(gridToCRS));
params.parameter("yPeriod").setValue(7 * XAffineTransform.getScaleY0(gridToCRS));
coverage = (GridCoverage2D) op.doOperation(params, null);
histogram = (javax.media.jai.Histogram) coverage
.getProperty(Histogram.GT_SYNTHETIC_PROPERTY_HISTOGRAM);
assertEquals(0, histogram.getBinSize(0, 255));
assertEquals(0, histogram.getBinSize(0, 60));
assertEquals(1, histogram.getBinSize(0, 56));
}
}