org.geotoolkit.coverage.processing
Class AbstractCoverageProcessor

Object
  Factory
      AbstractCoverageProcessor

All Implemented Interfaces:

Localized, GridCoverageProcessor

Direct Known Subclasses:

CachingCoverageProcessor, DefaultCoverageProcessor

@ThreadSafe
public abstract class AbstractCoverageProcessor
extends Factory
implements GridCoverageProcessor, Localized

Provides operations for different ways of accessing the grid coverage values as well as image processing functionality. The list of available processing operations is implementation dependent. The class has a discovery mechanism to determine the available processing operations.

These processing operations will transform values within a single sample dimension, and leave the values in other sample dimensions unaffected. The modified sample dimension may also change its type (e.g. from UNSIGNED_4BITS to UNSIGNED_1BIT). The actual underlying grid data remains unchanged.

The class has been designed to allow the adaptations to be done in a "pipe-lined" manner. The class operates on Coverage to create new a Coverage. The class does not need to make a copy of the source grid data. Instead, it can return a grid coverage object which applies the adaptations on the original grid coverage whenever a block of data is requested. In this way, a pipeline of several grid coverages can be constructed cheaply.

This class can perform any of the following:

• Change the number of bands being accessed.
• Change the value sequencing in which the grid values are retrieved.
• Allow re-sampling of the grid coverage for a different geometry. Creating a new Coverage with different grid geometry allows for reprojecting the grid coverage to another projection and another georeferencing type, resampling to another cell resolution and subsetting the grid coverage.
• Modify the way the grid values are accessed (filtered, classified...).
• Change the interpolation method used when evaluating points which fall between grid cells.
• Filtering.
• Image enhancements.
• etc.

Since:

2.2

Version:

3.00

Author:

Martin Desruisseaux (IRD)

Module:

coverage/geotk-coverage (download)

View source code for this class

Nested Class Summary

Nested classes/interfaces inherited from class Factory

Factory.Availability, Factory.Organizer

Field Summary

static Logger	LOGGER The logger for coverage processing operations.
static Level	OPERATION The logging level for reporting coverage operations.

Fields inherited from class Factory

EMPTY_HINTS, hints

Constructor Summary

protected

AbstractCoverageProcessor() Constructs a coverage processor.

Method Summary

abstract Coverage	doOperation(ParameterValueGroup parameters) Applies an operation.
static AbstractCoverageProcessor	getInstance() Returns a default processor instance.
Locale	getLocale() The locale for logging message or reporting errors.
abstract Operation	getOperation(String name) Returns the operation for the specified name.
abstract Collection<Operation>	getOperations() Retrieves grid processing operations information.
void	listOperations(Writer out) Lists a summary of all operations to the specified stream.
void	printOperations(Writer out, String[] names) Prints a description of operations to the specified stream.

Methods inherited from class Factory

availability, dispose, equals, getImplementationHints, hasCompatibleHints, hashCode, setOrdering, toString

Methods inherited from class Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

LOGGER

public static final Logger LOGGER

The logger for coverage processing operations.

OPERATION

public static final Level OPERATION

The logging level for reporting coverage operations. This level is equals or slightly lower than Level.INFO.

Constructor Detail

AbstractCoverageProcessor

protected AbstractCoverageProcessor()

Constructs a coverage processor.

Method Detail

getInstance

public static AbstractCoverageProcessor getInstance()

Returns a default processor instance. This method is a shortcut for CoverageFactoryFinder.getCoverageProcessor(Hints) with hints asking for an instance of AbstractCoverageProcessor.

Returns:

The default processor instance.

getOperations

public abstract Collection<Operation> getOperations()

Retrieves grid processing operations information. Each operation information contains the name of the operation as well as a list of its parameters.

Specified by:

getOperations in interface GridCoverageProcessor

Returns:

The available processing operations

getOperation

public abstract Operation getOperation(String name)
                                throws OperationNotFoundException

Returns the operation for the specified name.

Parameters:

name - Name of the operation.

Returns:

The operation for the given name.

Throws:

OperationNotFoundException - if there is no operation for the specified name.

doOperation

public abstract Coverage doOperation(ParameterValueGroup parameters)
                              throws OperationNotFoundException,
                                     CoverageProcessingException

Applies an operation.

Parameters:

parameters - Parameters required for the operation.

Returns:

The result as a coverage.

Throws:

OperationNotFoundException - if there is no operation for the parameter group name.

CoverageProcessingException - if the operation can not be executed.

getLocale

public Locale getLocale()

The locale for logging message or reporting errors. The default implementations returns the default locale. Subclasses can override this method if a different locale is wanted.

Specified by:

getLocale in interface Localized

Returns:

The locale for logging message.

listOperations

public void listOperations(Writer out)
                    throws IOException

Lists a summary of all operations to the specified stream.

Parameters:

out - The destination stream.

Throws:

IOException - if an error occurred will writing to the stream.

printOperations

public void printOperations(Writer out,
                            String[] names)
                     throws OperationNotFoundException,
                            IOException

Prints a description of operations to the specified stream. If the names array is non-null, then only the specified operations are printed. Otherwise, all operations are printed. The description details include operation names and lists of parameters.

Parameters:

out - The destination stream.

names - The operation to print, or an empty array for none, or null for all.

Throws:

IOException - if an error occurred will writing to the stream.

OperationNotFoundException - if an operation named in names was not found.