BEAM

GPF Operator API to provide better support for image filters and convolutions

Details

  • Type: New Feature New Feature
  • Status: Closed Closed
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: 4.7
  • Fix Version/s: 4.7.1, 4.8
  • Component/s: Graph Processing Framework
  • Labels:
    None

Description

For developers wanting to implement custom image filters or convolutions, it is currently not obvious how to best achieve this using the GPF Operator API.
Client GPF Operator code, that compute target pixels from a region around a corresponding source pixel, always have to deal with the nasty image border problem.

A simple improvement could be to add the following method to the Operator interface:

/**
 * Reads a source tile whose region can overlap the bounds of source image.
 * This method is particulary useful if you need to compute target pixels from an n x m region around a corresponding source pixel.
 * In this case an extended tile will need to be read from the source.
 *
 * @param b the band providing the source image from which the tile is read
 * @param r the requested tile region. This region might overlap the bounds of source image
 * @param be a strategy used to fill the raster regions that lie outside the bounds of the source image
 * @return a tile whose region can overlap the bounds of source image
 */
Tile getSourceTile(RasterDataNode b, Rectangle r, BorderExtender be);


Activity

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Norman Fomferra made changes -
Field Original Value New Value
Assignee Marco Zühlke [ marcoz ] Norman Fomferra [ norman ]
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Norman Fomferra added a comment -
Added new method to Operator interface.
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Norman Fomferra added a comment - Added new method to Operator interface.
Norman Fomferra made changes -
Resolution Fixed [ 1 ]
Status Open [ 1 ] Resolved [ 5 ]
Norman Fomferra made changes -
Fix Version/s 4.7.1 [ 10353 ]
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Norman Fomferra added a comment -
package org.esa.beam.framework.gpf;

import com.bc.ceres.core.ProgressMonitor;
import junit.framework.TestCase;
import org.esa.beam.framework.datamodel.Band;
import org.esa.beam.framework.datamodel.Product;
import org.esa.beam.framework.datamodel.ProductData;
import org.esa.beam.framework.gpf.annotations.Parameter;
import org.esa.beam.framework.gpf.annotations.SourceProduct;
import org.esa.beam.framework.gpf.annotations.TargetProduct;

import javax.media.jai.BorderExtenderConstant;
import java.awt.Rectangle;
import java.awt.image.Raster;


public class AreaOperatorTest extends TestCase {

    public void testBasicOperatorStates() throws OperatorException {
        Product sourceProduct = new Product("foo", "grunt", 4, 4);
        Band band = sourceProduct.addBand("bar", ProductData.TYPE_FLOAT32);
        band.setRasterData(ProductData.createInstance(new float[]{
                1, 2, 3, 4,
                2, 3, 4, 5,
                3, 4, 5, 6,
                4, 5, 6, 7,
        }));

        final SomeAreaOp op = new SomeAreaOp();
        op.setSourceProduct(sourceProduct);
        op.bandName = band.getName();
        op.kernelSize = 3;

        Product targetProduct = op.getTargetProduct();
        Raster data = targetProduct.getBand(op.bandName).getSourceImage().getData();

        final float X = Float.NaN;
        float[] expectedSamples = new float[]{
                X, X, X, X,
                X, 1, 2, X,
                X, 2, 3, X,
                X, X, X, X,
        };

        for (int i = 0; i < expectedSamples.length; i++) {
            float expectedSample = expectedSamples[i];
            assertEquals(expectedSample, data.getSampleFloat(i % 4, i / 4, 0));
        }

    }

    private static class SomeAreaOp extends Operator {

        @SourceProduct
        private Product sourceProduct;
        @TargetProduct
        private Product targetProduct;
        @Parameter
        String bandName;
        @Parameter(defaultValue = "3")
        int kernelSize;

        private Band sourceBand;
        private Band targetBand;

        @Override
        public void initialize() throws OperatorException {
            sourceBand = sourceProduct.getBand(bandName);
            targetProduct = new Product(sourceProduct.getName(), sourceProduct.getProductType(),
                                        sourceProduct.getSceneRasterWidth(), sourceProduct.getSceneRasterHeight());
            targetBand = targetProduct.addBand(bandName, sourceBand.getDataType());
        }

        @Override
        public void computeTile(Band band, Tile tile, ProgressMonitor pm) throws OperatorException {
            if (band == targetBand) {
                int border = kernelSize / 2;
                Rectangle sourceRegion = tile.getRectangle();
                sourceRegion.grow(border, border);
                Tile sourceTile = getSourceTile(sourceBand, sourceRegion, new BorderExtenderConstant(new double[]{Double.NaN}), ProgressMonitor.NULL);
                for (int y = tile.getMinY(); y <= tile.getMaxY(); y++) {
                    for (int x = tile.getMinX(); x <= tile.getMaxX(); x++) {
                        tile.setSample(x, y, computeMin(sourceTile, x, y, border));
                    }
                }
            }
        }

        private double computeMin(Tile sourceTile, int x, int y, int border) {
            double min = Double.MAX_VALUE;
            for (int j = y - border; j <= y + border; j++) {
                for (int i = x - border; i <= x + border; i++) {
                    min = Math.min(min, sourceTile.getSampleDouble(i, j));
                }
            }
            return min;
        }
    }
}
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Norman Fomferra added a comment - package org.esa.beam.framework.gpf; import com.bc.ceres.core.ProgressMonitor; import junit.framework.TestCase; import org.esa.beam.framework.datamodel.Band; import org.esa.beam.framework.datamodel.Product; import org.esa.beam.framework.datamodel.ProductData; import org.esa.beam.framework.gpf.annotations.Parameter; import org.esa.beam.framework.gpf.annotations.SourceProduct; import org.esa.beam.framework.gpf.annotations.TargetProduct; import javax.media.jai.BorderExtenderConstant; import java.awt.Rectangle; import java.awt.image.Raster; public class AreaOperatorTest extends TestCase {     public void testBasicOperatorStates() throws OperatorException {         Product sourceProduct = new Product("foo", "grunt", 4, 4);         Band band = sourceProduct.addBand("bar", ProductData.TYPE_FLOAT32);         band.setRasterData(ProductData.createInstance(new float[]{                 1, 2, 3, 4,                 2, 3, 4, 5,                 3, 4, 5, 6,                 4, 5, 6, 7,         }));         final SomeAreaOp op = new SomeAreaOp();         op.setSourceProduct(sourceProduct);         op.bandName = band.getName();         op.kernelSize = 3;         Product targetProduct = op.getTargetProduct();         Raster data = targetProduct.getBand(op.bandName).getSourceImage().getData();         final float X = Float.NaN;         float[] expectedSamples = new float[]{                 X, X, X, X,                 X, 1, 2, X,                 X, 2, 3, X,                 X, X, X, X,         };         for (int i = 0; i < expectedSamples.length; i++) {             float expectedSample = expectedSamples[i];             assertEquals(expectedSample, data.getSampleFloat(i % 4, i / 4, 0));         }     }     private static class SomeAreaOp extends Operator {         @SourceProduct         private Product sourceProduct;         @TargetProduct         private Product targetProduct;         @Parameter         String bandName;         @Parameter(defaultValue = "3")         int kernelSize;         private Band sourceBand;         private Band targetBand;         @Override         public void initialize() throws OperatorException {             sourceBand = sourceProduct.getBand(bandName);             targetProduct = new Product(sourceProduct.getName(), sourceProduct.getProductType(),                                         sourceProduct.getSceneRasterWidth(), sourceProduct.getSceneRasterHeight());             targetBand = targetProduct.addBand(bandName, sourceBand.getDataType());         }         @Override         public void computeTile(Band band, Tile tile, ProgressMonitor pm) throws OperatorException {             if (band == targetBand) {                 int border = kernelSize / 2;                 Rectangle sourceRegion = tile.getRectangle();                 sourceRegion.grow(border, border);                 Tile sourceTile = getSourceTile(sourceBand, sourceRegion, new BorderExtenderConstant(new double[]{Double.NaN}), ProgressMonitor.NULL);                 for (int y = tile.getMinY(); y <= tile.getMaxY(); y++) {                     for (int x = tile.getMinX(); x <= tile.getMaxX(); x++) {                         tile.setSample(x, y, computeMin(sourceTile, x, y, border));                     }                 }             }         }         private double computeMin(Tile sourceTile, int x, int y, int border) {             double min = Double.MAX_VALUE;             for (int j = y - border; j <= y + border; j++) {                 for (int i = x - border; i <= x + border; i++) {                     min = Math.min(min, sourceTile.getSampleDouble(i, j));                 }             }             return min;         }     } }
Marco Peters made changes -
Status Resolved [ 5 ] Closed [ 6 ]

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  • Assignee:
    Norman Fomferra
    Reporter:
    Norman Fomferra
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