org.geotools.coverage.processing.operation
Class Resample

Object
  AbstractOperation
      Operation2D
          Resample

All Implemented Interfaces:

Serializable, Operation

public class Resample
extends Operation2D

Resample a grid coverage using a different grid geometry. This operation provides the following functionality:

• Resampling
  The grid coverage can be resampled at a different cell resolution. Some implementations may be able to do resampling efficiently at any resolution. Also a non-rectilinear grid coverage can be accessed as rectilinear grid coverage with this operation.
• Reprojecting
  The new grid geometry can have a different coordinate reference system than the underlying grid geometry. For example, a grid coverage can be reprojected from a geodetic coordinate reference system to Universal Transverse Mercator CRS.
• Subsetting
  A subset of a grid can be viewed as a separate coverage by using this operation with a grid geometry which as the same geoferencing and a region. Grid range in the grid geometry defines the region to subset in the grid coverage.

Geotools extension:
The "Resample" operation use the default CoordinateOperationFactory for creating a transformation from the source to the destination coordinate reference systems. If a custom factory is desired, it may be supplied as a rendering hint with the Hints.COORDINATE_OPERATION_FACTORY key. Rendering hints can be supplied to DefaultProcessor at construction time.

Name: "Resample"
JAI operator: "Affine" or "Warp"
Parameters:

Name	Class	Default value	Minimum value	Maximum value
"Source"	GridCoverage2D	N/A	N/A	N/A
"InterpolationType"	CharSequence	"NearestNeighbor"	N/A	N/A
"CoordinateReferenceSystem"	CoordinateReferenceSystem	Same as source grid coverage	N/A	N/A
"GridGeometry"	GridGeometry	(automatic)	N/A	N/A
"BackgroundValues"	double[]	N/A	N/A	N/A

Since:

2.2

Author:

Martin Desruisseaux (IRD), Giannecchini Simone, GeoSolutions SAS, Daniele Romagnoli, GeoSolutions SAS

See Also:

Operations.resample(org.opengis.coverage.Coverage, org.opengis.referencing.crs.CoordinateReferenceSystem), WarpDescriptor, Serialized Form

Field Summary

static ParameterDescriptor<double[]>	BACKGROUND_VALUES The parameter descriptor for the BackgroundValues.
static ParameterDescriptor<CoordinateReferenceSystem>	COORDINATE_REFERENCE_SYSTEM The parameter descriptor for the coordinate reference system.
static String	GRID_DIMENSIONS Key for the warp grid dimensions, available only if a WarpGrid is being used.
static ParameterDescriptor<GridGeometry>	GRID_GEOMETRY The parameter descriptor for the grid geometry.
static ParameterDescriptor<Object>	INTERPOLATION_TYPE The parameter descriptor for the interpolation type.
static String	OPERATION Key for the reprojection operation being used (null if no operation is performed)
static String	WARP_TYPE Key for the warp operation Class, null otherwise

Fields inherited from class Operation2D

PRIMARY_SOURCE_INDEX, SOURCE_0

Fields inherited from class AbstractOperation

descriptor

Constructor Summary

Resample()
Constructs a "Resample" operation.

Method Summary

static GridGeometry	computeGridGeometry(GridCoverage source, Envelope target) Computes a grid geometry from a source coverage and a target envelope.
Coverage	doOperation(ParameterValueGroup parameters, Hints hints) Resamples a grid coverage.

Methods inherited from class Operation2D

computeOnGeophysicsValues, extractSources, getFactory

Methods inherited from class AbstractOperation

equals, getDescription, getDocURL, getName, getNumSources, getParameters, getVendor, getVersion, hashCode, toString

Methods inherited from class Object

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

Field Detail

INTERPOLATION_TYPE

public static final ParameterDescriptor<Object> INTERPOLATION_TYPE

The parameter descriptor for the interpolation type.

COORDINATE_REFERENCE_SYSTEM

public static final ParameterDescriptor<CoordinateReferenceSystem> COORDINATE_REFERENCE_SYSTEM

The parameter descriptor for the coordinate reference system.

GRID_GEOMETRY

public static final ParameterDescriptor<GridGeometry> GRID_GEOMETRY

The parameter descriptor for the grid geometry.

BACKGROUND_VALUES

public static final ParameterDescriptor<double[]> BACKGROUND_VALUES

The parameter descriptor for the BackgroundValues.

OPERATION

public static final String OPERATION

Key for the reprojection operation being used (null if no operation is performed)

See Also:

Constant Field Values

WARP_TYPE

public static final String WARP_TYPE

Key for the warp operation Class, null otherwise

See Also:

Constant Field Values

GRID_DIMENSIONS

public static final String GRID_DIMENSIONS

Key for the warp grid dimensions, available only if a WarpGrid is being used. Returned as a Dimension object

See Also:

Constant Field Values

Constructor Detail

Resample

public Resample()

Constructs a "Resample" operation.

Method Detail

doOperation

public Coverage doOperation(ParameterValueGroup parameters,
                            Hints hints)

Resamples a grid coverage. This method is invoked by DefaultProcessor for the "Resample" operation.

Specified by:

doOperation in class AbstractOperation

Parameters:

parameters - List of name value pairs for the parameters required for the operation.

hints - A set of rendering hints, or null if none. The DefaultProcessor may provides hints for the following keys: Hints.COORDINATE_OPERATION_FACTORY and Hints.JAI_INSTANCE.

Returns:

The result as a coverage.

computeGridGeometry

public static GridGeometry computeGridGeometry(GridCoverage source,
                                               Envelope target)
                                        throws TransformException

Computes a grid geometry from a source coverage and a target envelope. This is a convenience method for computing the GRID_GEOMETRY argument of a "resample" operation from an envelope. The target envelope may contains a different coordinate reference system, in which case a reprojection will be performed.

Parameters:

source - The source coverage.

target - The target envelope, including a possibly different coordinate reference system.

Returns:

A grid geometry inferred from the target envelope.

Throws:

TransformException - If a transformation was required and failed.

Since:

2.5