javax.media.jai.operator
Class DivideByConstDescriptor

java.lang.Object
  |
  +--javax.media.jai.OperationDescriptorImpl
        |
        +--javax.media.jai.operator.DivideByConstDescriptor
All Implemented Interfaces:
OperationDescriptor, RegistryElementDescriptor, Serializable

public class DivideByConstDescriptor
extends OperationDescriptorImpl

An OperationDescriptor describing the "DivideByConst" operation.

The DivideByConst operation takes one rendered or renderable source image and an array of double constants, and divides every pixel of the same band of the source by the constant from the corresponding array entry. If the number of constants supplied is less than the number of bands of the destination, then the constant from entry 0 is applied to all the bands. Otherwise, a constant from a different entry is applied to each band.

In case of division by 0, if the numerator is 0, then the result is set to 0; otherwise, the result is set to the maximum value supported by the destination data type.

By default, the destination image bound, data type, and number of bands are the same as the source image. If the result of the operation underflows/overflows the minimum/maximum value supported by the destination data type, then it will be clamped to the minimum/maximum value respectively.

The destination pixel values are defined by the pseudocode:

 if (constants.length < dstNumBands) {
     dst[x][y][b] = srcs[x][y][b]/constants[0];
 } else {
     dst[x][y][b] = srcs[x][y][b]/constants[b];
 }
 

Resource List
Name Value
GlobalName DivideByConst
LocalName DivideByConst
Vendor com.sun.media.jai
Description Divides an image by constants.
DocURL http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/DivideByConstDescriptor.html
Version 1.0
arg0Desc The constants to be divided by.

Parameter List
Name Class Type Default Value
constants double[] {1.0}

See Also:
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
DivideByConstDescriptor()
          Constructor.
 
Method Summary
static RenderedOp create(RenderedImage source0, double[] constants, RenderingHints hints)
          Divides an image by constants.
static RenderableOp createRenderable(RenderableImage source0, double[] constants, RenderingHints hints)
          Divides an image by constants.
 boolean isRenderableSupported()
          Returns true since renderable operation is supported.
protected  boolean validateParameters(ParameterBlock args, StringBuffer message)
          Validates the input parameters.
 
Methods inherited from class javax.media.jai.OperationDescriptorImpl
arePropertiesSupported, getDefaultSourceClass, getDestClass, getDestClass, getInvalidRegion, getName, getNumParameters, getNumSources, getParamClasses, getParamDefaults, getParamDefaultValue, getParameterListDescriptor, getParamMaxValue, getParamMinValue, getParamNames, getPropertyGenerators, getPropertyGenerators, getRenderableDestClass, getRenderableSourceClasses, getResourceBundle, getResources, getSourceClasses, getSourceClasses, getSourceNames, getSupportedModes, isImmediate, isModeSupported, isRenderedSupported, makeDefaultSourceClassList, validateArguments, validateArguments, 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

DivideByConstDescriptor

public DivideByConstDescriptor()
Constructor.
Method Detail

isRenderableSupported

public boolean isRenderableSupported()
Returns true since renderable operation is supported.
Overrides:
isRenderableSupported in class OperationDescriptorImpl
Following copied from class: javax.media.jai.OperationDescriptorImpl
See Also:
OperationDescriptorImpl.isModeSupported(java.lang.String)

validateParameters

protected boolean validateParameters(ParameterBlock args,
                                     StringBuffer message)
Validates the input parameters.

In addition to the standard checks performed by the superclass method, this method checks that the length of the "constants" array is at least 1.

Overrides:
validateParameters in class OperationDescriptorImpl
Following copied from class: javax.media.jai.OperationDescriptorImpl
Throws:
IllegalArgumentException - if args is null.
IllegalArgumentException - if msg is null and the validation fails.
See Also:
OperationDescriptorImpl.validateParameters(java.lang.String, java.awt.image.renderable.ParameterBlock, java.lang.StringBuffer)

create

public static RenderedOp create(RenderedImage source0,
                                double[] constants,
                                RenderingHints hints)
Divides an image by constants.

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

Parameters:
source0 - RenderedImage source 0.
constants - The constants to be divided by. 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

createRenderable

public static RenderableOp createRenderable(RenderableImage source0,
                                            double[] constants,
                                            RenderingHints hints)
Divides an image by constants.

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

Parameters:
source0 - RenderableImage source 0.
constants - The constants to be divided by. May be null.
hints - The RenderingHints to use. May be null.
Returns:
The RenderableOp destination.
Throws:
IllegalArgumentException - if source0 is null.
See Also:
JAI, ParameterBlockJAI, RenderableOp