javax.media.jai.operator
Class MeanDescriptor

java.lang.Object
  extended byjavax.media.jai.OperationDescriptorImpl
      extended byjavax.media.jai.operator.MeanDescriptor
All Implemented Interfaces:
OperationDescriptor, RegistryElementDescriptor, Serializable

public class MeanDescriptor
extends OperationDescriptorImpl

An OperationDescriptor describing the "Mean" operation.

The Mean operation scans a specific region of a rendered image and computes the mean pixel value for each band within that region of the image. The image data pass through this operation unchanged.

The region-wise mean pixel value for each band may be retrieved by calling the getProperty method on this operation with "mean" as the property name. The return value has type double[#bands].

The region of interest (ROI) does not have to be a rectangle. It may be null, in which case the entire image is scanned to find the image-wise mean pixel value for each band.

The set of pixels scanned may be further reduced by specifying the "xPeriod" and "yPeriod" parameters that represent the sampling rate along each axis. These variables may not be less than 1. However, they may be null, in which case the sampling rate is set to 1; that is, every pixel in the ROI is processed.

Resource List
Name Value
GlobalName Mean
LocalName Mean
Vendor com.sun.media.jai
Description Calculates the region-wise mean pixel value for each band of an image.
DocURL http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/MeanDescriptor.html
Version 1.0
arg0Desc The region of the image to scan.
arg1Desc The horizontal sampling rate, may not be less than 1.
arg2Desc The vertical sampling rate, may not be less than 1.

Parameter List
Name Class Type Default Value
roi javax.media.jai.ROI null
xPeriod java.lang.Integer 1
yPeriod java.lang.Integer 1

See Also:
ROI, OperationDescriptor, Serialized Form

Field Summary
 
Fields inherited from class javax.media.jai.OperationDescriptorImpl
sourceNames, supportedModes
 
Fields inherited from interface javax.media.jai.OperationDescriptor
NO_PARAMETER_DEFAULT
 
Constructor Summary
MeanDescriptor()
          Constructor.
 
Method Summary
static RenderedOp create(RenderedImage source0, ROI roi, Integer xPeriod, Integer yPeriod, RenderingHints hints)
          Calculates the image-wise mean pixel value for each band of an image.
 Number getParamMinValue(int index)
          Returns the minimum legal value of a specified numeric parameter for this operation.
 
Methods inherited from class javax.media.jai.OperationDescriptorImpl
arePropertiesSupported, getDefaultSourceClass, getDestClass, getDestClass, getInvalidRegion, getName, getNumParameters, getNumSources, getParamClasses, getParamDefaults, getParamDefaultValue, getParameterListDescriptor, getParamMaxValue, getParamNames, getPropertyGenerators, getPropertyGenerators, getRenderableDestClass, getRenderableSourceClasses, getResourceBundle, getResources, getSourceClasses, getSourceClasses, getSourceNames, getSupportedModes, isImmediate, isModeSupported, isRenderableSupported, isRenderedSupported, makeDefaultSourceClassList, validateArguments, validateArguments, validateParameters, validateParameters, validateRenderableArguments, validateRenderableSources, validateSources, validateSources
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

MeanDescriptor

public MeanDescriptor()
Constructor.

Method Detail

getParamMinValue

public Number getParamMinValue(int index)
Returns the minimum legal value of a specified numeric parameter for this operation.

Specified by:
getParamMinValue in interface OperationDescriptor
Overrides:
getParamMinValue in class OperationDescriptorImpl
Parameters:
index - The index of the parameter to be queried.
Returns:
A Number representing the minimum legal value, or null if the specified parameter is not numeric.
See Also:
ParameterListDescriptor.getParamValueRange(java.lang.String), ParameterListDescriptor.getEnumeratedParameterValues(java.lang.String), ParameterListDescriptor.isParameterValueValid(java.lang.String, java.lang.Object)

create

public static RenderedOp create(RenderedImage source0,
                                ROI roi,
                                Integer xPeriod,
                                Integer yPeriod,
                                RenderingHints hints)
Calculates the image-wise mean pixel value for each band of an image.

Creates a ParameterBlockJAI from all supplied arguments except hints and invokes JAI.create(String,ParameterBlock,RenderingHints).

Parameters:
source0 - RenderedImage source 0.
roi - The region of the image to scan. May be null.
xPeriod - The horizontal sampling rate, may not be less than 1. May be null.
yPeriod - The vertical sampling rate, may not be less than 1. May be null.
hints - The RenderingHints to use. May be null.
Returns:
The RenderedOp destination.
Throws:
IllegalArgumentException - if source0 is null.
See Also:
JAI, ParameterBlockJAI, RenderedOp