javax.media.jai.operator
Class MeanDescriptor

java.lang.Object
  |
  +--javax.media.jai.OperationDescriptorImpl
        |
        +--javax.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

Fields inherited from class javax.media.jai.OperationDescriptorImpl

resources, 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.

Overrides:

getParamMinValue in class OperationDescriptorImpl

Following copied from class: javax.media.jai.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.

Throws:

IllegalArgumentException - if this operation has no parameters.

ArrayIndexOutOfBoundsException - if there is no parameter corresponding to the specified index.

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