javax.media.jai.operator
Class ExtremaDescriptor

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

All Implemented Interfaces:

OperationDescriptor, RegistryElementDescriptor, Serializable

public class ExtremaDescriptor

extends OperationDescriptorImpl

An OperationDescriptor describing the "Extrema" operation.

The Extrema operation scans a specific region of a rendered image and finds the maximum and minimum pixel values for each band within that region of the image. The image data pass through this operation unchanged.

The region-wise maximum and minimum pixel values may be obtained as properties. Calling the getProperty method on this operation with "extrema" as the property name retrieves both the region-wise maximum and minimum pixel values. Calling it with "maximum" as the property name retrieves the region-wise maximum pixel value, and with "minimum" as the property name retrieves the region-wise minimum pixel value. The return value for "extrema" has type double[2][#bands], and those for "maximum" and "minimum" have 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 maximum and minimum pixel values 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	Extrema
LocalName	Extrema
Vendor	com.sun.media.jai
Description	Finds the maximum and minimum pixel value in each band of an image.
DocURL	http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/ExtremaDescriptor.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:

OperationDescriptor, Serialized Form

Fields inherited from class javax.media.jai.OperationDescriptorImpl

resources, sourceNames, supportedModes

Constructor Summary

ExtremaDescriptor()
Constructor.

Method Summary

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

ExtremaDescriptor

public ExtremaDescriptor()

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

Tags copied from 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.

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)