org.geotools.coverage.processing.operation
Class Histogram

Object
  extended by AbstractOperation
      extended by Operation2D
          extended by OperationJAI
              extended by AbstractStatisticsOperationJAI
                  extended by Histogram
All Implemented Interfaces:
Serializable, Operation

public class Histogram
extends AbstractStatisticsOperationJAI

* This operation simply wraps JAI Histogram operations described by HistogramDescriptor inside a GeoTools operation in order to make it spatial-aware.

For the moment this is a very simple wrap. Plans on the 2.4 and successive versions of this operation are to add the ability to use spatial ROIs and to specific Spatial subsampling. As of now, ROI has to be a Java2D Shape subclass and the parameters to control x and y subsamplings got to be Integer, which means pixel-aware.

For more information on how the underlying JAI operators works you can have a look here: HistogramDescriptor Histogram of the source coverage. final OperationJAI op=new OperationJAI("Histogram"); ParameterValueGroup params = op.getParameters(); params.parameter("Source").setValue(coverage); coverage=(GridCoverage2D) op.doOperation(params,null); System.out.println(((double[])coverage.getProperty("histogram")));

Since:
2.4
Author:
Simone Giannecchini
See Also:
Histogram, Serialized Form
Module:
modules/library/coverage (gt-coverage.jar)

Nested Class Summary
 
Nested classes/interfaces inherited from class OperationJAI
OperationJAI.Parameters
 
Field Summary
static String GT_SYNTHETIC_PROPERTY_HISTOGRAM
          String key for getting the Histogram object.
 
Fields inherited from class AbstractStatisticsOperationJAI
LOGGER, ROI, SPATIAL_SUBSAMPLING_X, SPATIAL_SUBSAMPLING_Y
 
Fields inherited from class OperationJAI
operation, RENDERED_MODE
 
Fields inherited from class Operation2D
PRIMARY_SOURCE_INDEX, SOURCE_0
 
Fields inherited from class AbstractOperation
descriptor
 
Constructor Summary
Histogram()
          Default constructor for the Histogram operation.
 
Method Summary
protected  boolean computeOnGeophysicsValues(ParameterValueGroup parameters)
          This operation MUST be performed on the geophysics data for this GridCoverage2D.
protected  Map<String,?> getProperties(RenderedImage data, CoordinateReferenceSystem crs, InternationalString name, MathTransform toCRS, GridCoverage2D[] sources, OperationJAI.Parameters parameters)
          Prepare the Histogram property for this histogram operation.
 
Methods inherited from class AbstractStatisticsOperationJAI
prepareParameters
 
Methods inherited from class OperationJAI
createRenderedImage, deriveCategory, deriveGridCoverage, deriveName, deriveRange, deriveSampleDimension, deriveUnit, doOperation, equals, getJAI, getOperationDescriptor, getQuantitative, resampleToCommonGeometry
 
Methods inherited from class Operation2D
extractSources, getFactory
 
Methods inherited from class AbstractOperation
ensureNonNull, getDescription, getDocURL, getName, getNumSources, getParameters, getProcessor, getVendor, getVersion, hashCode, toString
 
Methods inherited from class Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

GT_SYNTHETIC_PROPERTY_HISTOGRAM

public static final String GT_SYNTHETIC_PROPERTY_HISTOGRAM
String key for getting the Histogram object.

See Also:
Constant Field Values
Constructor Detail

Histogram

public Histogram()
          throws OperationNotFoundException
Default constructor for the Histogram operation.

Throws:
OperationNotFoundException
Method Detail

computeOnGeophysicsValues

protected boolean computeOnGeophysicsValues(ParameterValueGroup parameters)
This operation MUST be performed on the geophysics data for this GridCoverage2D.

Overrides:
computeOnGeophysicsValues in class Operation2D
Parameters:
parameters - ParameterValueGroup that describes this operation
Returns:
always true.
See Also:
GridCoverage2D.geophysics(boolean)

getProperties

protected Map<String,?> getProperties(RenderedImage data,
                                      CoordinateReferenceSystem crs,
                                      InternationalString name,
                                      MathTransform toCRS,
                                      GridCoverage2D[] sources,
                                      OperationJAI.Parameters parameters)
Prepare the Histogram property for this histogram operation.

See HistogramDescriptor for more info.

Overrides:
getProperties in class OperationJAI
Parameters:
data - The RenderedImage created by this operation.
crs - The coordinate reference system assigned to the coverage this OperationJAI will produce.
name - The name assigned to the coverage this OperationJAI will produce.
toCRS - The transform from grid to crs to be assigned to the coverage this OperationJAI will produce.
sources - The sources to be assigned to the coverage this OperationJAI will produce.
parameters - The parameters that were used by this OperationJAI.
Returns:
a Map with the properties generated by this OperationJAI or null if we haven't any.
See Also:
OperationJAI#getProperties(RenderedImage, CoordinateReferenceSystem, InternationalString, MathTransform, GridCoverage2D[], org.geotools.coverage.processing.OperationJAI.Parameters),


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