Package org.esa.snap.core.gpf.pointop

Class PointOperator

java.lang.Object

org.esa.snap.core.gpf.Operator

org.esa.snap.core.gpf.pointop.PointOperator

Direct Known Subclasses:

PixelOperator, SampleOperator

public abstract class PointOperator
extends Operator

The PointOperator class serves as a base class for operators

1. that compute single pixels independently of their neighbours and
2. whose target product and all source products share the same grid and coordinate reference system.

More specifically, the target product and all source products must share the same raster size and GeoCoding.

Since:

BEAM 4.9, revised in SNAP 2.0

Constructor Summary

Constructors

Constructor	Description
PointOperator()

Method Summary

Modifier and Type	Method	Description
protected final void	checkRasterSize()	Checks if all source products share the same raster size, otherwise throws an exception.
protected abstract void	configureSourceSamples(SourceSampleConfigurer sampleConfigurer)	Configures all source samples that this operator requires for the computation of target samples.
protected void	configureTargetProduct(ProductConfigurer productConfigurer)	Configures the target product via the given ProductConfigurer.
protected abstract void	configureTargetSamples(TargetSampleConfigurer sampleConfigurer)	Configures all target samples computed by this operator.
protected Product	createTargetProduct()	Creates the target product instance.
void	dispose()	Releases the resources the operator has acquired during its lifetime.
final void	initialize()	Configures this PointOperator by performing a number of initialisation steps in the given order: prepareInputs() createTargetProduct() configureTargetProduct(ProductConfigurer) configureSourceSamples(SourceSampleConfigurer) configureTargetSamples(TargetSampleConfigurer) This method cannot be overridden by intention (template method).
protected void	prepareInputs()	Prepares the inputs for this operator.

Methods inherited from class org.esa.snap.core.gpf.Operator

canComputeTile, canComputeTileStack, checkForCancellation, computeTile, computeTileStack, doExecute, ensureSceneGeoCoding, ensureSingleRasterSize, ensureSingleRasterSize, execute, finalize, getId, getLogger, getParameter, getParameter, getProductManager, getSourceProduct, getSourceProduct, getSourceProductId, getSourceProducts, getSourceTile, getSourceTile, getSpi, getTargetProduct, getTargetProperty, setLogger, setParameter, setParameterDefaultValues, setRequiresAllBands, setSourceProduct, setSourceProduct, setSourceProducts, setSpi, setTargetProduct, stopTileComputationObservation, update

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PointOperator

public PointOperator()

Method Details

initialize

public final void initialize()
                      throws OperatorException

Configures this PointOperator by performing a number of initialisation steps in the given order:

1. prepareInputs()
2. createTargetProduct()
3. configureTargetProduct(ProductConfigurer)
4. configureSourceSamples(SourceSampleConfigurer)
5. configureTargetSamples(TargetSampleConfigurer)

This method cannot be overridden by intention (template method). Instead clients may wish to override the methods that are called during the initialisation sequence.

Specified by:

initialize in class Operator

Throws:

OperatorException - If the configuration cannot be performed.

See Also:

• Operator.getTargetProduct()

prepareInputs

protected void prepareInputs()
                      throws OperatorException

Prepares the inputs for this operator. Called by initialize().

Clients may override to perform some extra validation of parameters and source products and/or to load external, auxiliary resources. External resources that may be opened by this method and that must remain open during the Operator's lifetime shall be closed by a dedicated override of the dispose() method.

Failures of input preparation shall be indicated by throwing an OperatorException.

The default implementation checks whether all source products have the same raster size. Clients that require a similar behaviour in their operator shall first call the super method in their implementation.

Throws:

OperatorException - If the validation of input fails.

dispose

public void dispose()

Description copied from class: Operator

Releases the resources the operator has acquired during its lifetime. The default implementation does nothing.

Overrides should make sure to call super.dispose() as well.

Overrides:

dispose in class Operator

createTargetProduct

protected Product createTargetProduct()
                               throws OperatorException

Creates the target product instance. Called by initialize().

The default implementation creates a target product instance given the raster size of the (first) source product.

Returns:

A new target product instance.

Throws:

OperatorException - If the target product cannot be created.

configureTargetProduct

protected void configureTargetProduct(ProductConfigurer productConfigurer)

Configures the target product via the given ProductConfigurer. Called by initialize().

Client implementations of this method usually add product components to the given target product, such as bands to be computed by this operator, virtual bands, masks or sample codings.

The default implementation retrieves the (first) source product and copies to the target product

• the start and stop time by calling ProductConfigurer.copyTimeCoding(),
• all tie-point grids by calling ProductConfigurer.copyTiePointGrids(String...),
• the geo-coding by calling ProductConfigurer.copyGeoCoding().

Clients that require a similar behaviour in their operator shall first call the super method in their implementation.

Parameters:

productConfigurer - The target product configurer.

Throws:

OperatorException - If the target product cannot be configured.

See Also:

• Product.addBand(Band)
• Product.addBand(String, String)
• Product.addTiePointGrid(TiePointGrid)
• Product.getMaskGroup()

configureSourceSamples

protected abstract void configureSourceSamples(SourceSampleConfigurer sampleConfigurer)
                                        throws OperatorException

Configures all source samples that this operator requires for the computation of target samples. Source sample are defined by using the provided SourceSampleConfigurer.

The method is called by initialize().

Parameters:

sampleConfigurer - The configurer that defines the layout of a pixel.

Throws:

OperatorException - If the source samples cannot be configured.

configureTargetSamples

protected abstract void configureTargetSamples(TargetSampleConfigurer sampleConfigurer)
                                        throws OperatorException

Configures all target samples computed by this operator. Target samples are defined by using the provided TargetSampleConfigurer.

The method is called by initialize().

Parameters:

sampleConfigurer - The configurer that defines the layout of a pixel.

Throws:

OperatorException - If the target samples cannot be configured.

checkRasterSize

protected final void checkRasterSize()
                              throws OperatorException

Checks if all source products share the same raster size, otherwise throws an exception. Called by initialize().

Throws:

OperatorException - If the source product's raster sizes are not equal.