org.geotoolkit.coverage.processing.operation
Class Resample

Object
  AbstractOperation
      Operation2D
          Resample

All Implemented Interfaces:

Serializable, Operation

@Immutable
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 envelope in the grid geometry defines the region to subset in the grid coverage.

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	"NearestNieghbor"	N/A	N/A
"CoordinateReferenceSystem"	CoordinateReferenceSystem	Same as source grid coverage	N/A	N/A
"GridGeometry"	GridGeometry	(automatic)	N/A	N/A
"Background"	double[]	(automatic)	N/A	N/A

Geotoolkit.org 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 DefaultCoverageProcessor at construction time.

Geotk adds a background parameter which is not part of OGC specification. This parameter specifies the color to use for pixels in the destination image that don't map to a pixel in the source image. If this parameter is not specified, then it is inferred from the "no data" category in the source coverage.

Since:

2.2

Version:

3.16

Author:

Martin Desruisseaux (IRD, Geomatys)

See Also:

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

Module:

coverage/geotk-coverage (download)

View source code for this class

Field Summary

static ParameterDescriptor<double[]>	BACKGROUND The parameter descriptor for the background values.
static ParameterDescriptor<CoordinateReferenceSystem>	COORDINATE_REFERENCE_SYSTEM The parameter descriptor for the coordinate reference system.
static ParameterDescriptor<GridGeometry>	GRID_GEOMETRY The parameter descriptor for the grid geometry.
static ParameterDescriptor<Object>	INTERPOLATION_TYPE The parameter descriptor for the interpolation type.

Fields inherited from class Operation2D

PRIMARY_SOURCE_INDEX, SOURCE_0, SOURCE_1, SOURCE_2

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.
protected Coverage	doOperation(ParameterValueGroup parameters, Hints hints) Resamples a grid coverage.

Methods inherited from class Operation2D

extractSources, extractSources, getComputationView

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

public static final ParameterDescriptor<double[]> BACKGROUND

The parameter descriptor for the background values.

Since:

3.16

Constructor Detail

Resample

public Resample()

Constructs a "Resample" operation.

Method Detail

doOperation

protected Coverage doOperation(ParameterValueGroup parameters,
                               Hints hints)

Resamples a grid coverage. This method is invoked by DefaultCoverageProcessor 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 DefaultCoverageProcessor 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