Threshold Class Reference

Inheritance diagram for Threshold:

Collaboration diagram for Threshold:

Public Member Functions
String	getURI ()
GridCoverage	modify (GridCoverage raster, Integer rd1, GridCoverage raster2, Integer rd2)
Value	evaluate (ValueFactory valueFactory, Value... args) throws ValueExprEvaluationException

Member Function Documentation

evaluate()

Value evaluate ( ValueFactory  valueFactory, Value...  args  ) throws ValueExprEvaluationException

inherited

                                                                                                            {
                if (args.length != 4) {
                        throw new ValueExprEvaluationException(getURI() + " requires exactly 4 arguments, got " + args.length);
                }
                LiteralType l=LiteralRegistry.getLiteral(((Literal)args[0]).getDatatype().toString());
                LiteralType l2=LiteralRegistry.getLiteral(((Literal)args[2]).getDatatype().toString());
                if(l instanceof RasterLiteral && l2 instanceof RasterLiteral) {
                        GridCoverage geom=((RasterLiteral)l).read(args[0].stringValue());
                        Integer bd1=Integer.valueOf(args[1].stringValue());
                        GridCoverage geom2=((RasterLiteral)l).read(args[2].stringValue());
                        Integer bd2=Integer.valueOf(args[3].stringValue());
                        GridCoverage result = modify(geom,bd1,geom2,bd2);
                        return valueFactory.createLiteral(((RasterLiteral) l).unparse(result),((Literal)args[0]).getDatatype());
                }
                return null;
        }

References LiteralRegistry.getLiteral(), and RasterAlgebraFunction.modify().

Referenced by AddTest.testAdd(), AndTest.testAnd(), DivTest.testDiv(), LogTest.testLog(), MultTest.testMult(), OrTest.testOr(), SubtractTest.testSubtract(), and XorTest.testXor().

getURI()

String getURI

(

)

                               {
                return POSTGIS.ST_rast_algebra_threshold.stringValue();
        }

References POSTGIS.ST_rast_algebra_threshold.

modify()

GridCoverage modify	(	GridCoverage	raster,
		Integer	rd1,
		GridCoverage	raster2,
		Integer	rd2
	)

Reimplemented from RasterAlgebraFunction.

                                                                                                        {
                ParameterBlock pbSubtracted = new ParameterBlock();
                pbSubtracted.addSource(raster.render(raster.getGridGeometry().getExtent()));
                pbSubtracted.addSource(raster2.render(raster2.getGridGeometry().getExtent()));
                RenderedOp subtractedImage = JAI.create("threshold", pbSubtracted);
                final SampleDimension sd = new SampleDimension.Builder().setName("t")
                                .addQuantitative(
                                                (raster.getSampleDimensions().get(rd1).getName() + "-"
                                                                + raster2.getSampleDimensions().get(rd2).getName()).toString(),
                                                raster.getSampleDimensions().get(0).getMeasurementRange().get(),
                                                raster.getSampleDimensions().get(0).getTransferFunction().get(),
                                                raster.getSampleDimensions().get(0).getUnits().get())
                                .build();
                
                List<SampleDimension>sds=new LinkedList<SampleDimension>();
                sds.add(sd);
                /*
                 * Create the grid coverage, gets its image and set values directly as short
                 * integers.
                 */
                BufferedGridCoverage coverage = new BufferedGridCoverage(raster2.getGridGeometry(),
                                sds, DataBuffer.TYPE_SHORT);
                WritableRaster rasterr = ((BufferedImage) coverage.render(null)).getRaster();
                rasterr.setRect(subtractedImage.getSourceImage(0).getData());
                return coverage;
        }