javax.media.jai.operator
Class PiecewiseDescriptor

java.lang.Object
  javax.media.jai.OperationDescriptorImpl
      javax.media.jai.operator.PiecewiseDescriptor

All Implemented Interfaces:

OperationDescriptor, RegistryElementDescriptor, Serializable

public class PiecewiseDescriptor

extends OperationDescriptorImpl

An OperationDescriptor describing the "Piecewise" operation.

The "Piecewise" operation performs a piecewise linear mapping of the pixel values of an image. The piecewise linear mapping is described by a set of breakpoints which are provided as an array of the form

float breakPoints[N][2][numBreakPoints]

where the value of N may be either unity or the number of bands in the source image. If N is unity then the same set of breakpoints will be applied to all bands in the image. The abscissas of the supplied breakpoints must be monotonically increasing.

The pixel values of the destination image are defined by the pseudocode:

 if (src[x][y][b] < breakPoints[b][0][0]) {
     dst[x][y][b] = breakPoints[b][1][0]);
 } else if (src[x][y][b] > breakPoints[b][0][numBreakPoints-1]) {
     dst[x][y][b] = breakPoints[b][1][numBreakPoints-1]);
 } else {
     int i = 0;
     while(breakPoints[b][0][i+1] < src[x][y][b]) {
         i++;
     }
     dst[x][y][b] = breakPoints[b][1][i] +
                        (src[x][y][b] - breakPoints[b][0][i])*
                        (breakPoints[b][1][i+1] - breakPoints[b][1][i])/
                        (breakPoints[b][0][i+1] - breakPoints[b][0][i]);
 }
 

Resource List

Name	Value
GlobalName	Piecewise
LocalName	Piecewise
Vendor	com.sun.media.jai
Description	Applies a piecewise pixel value mapping.
DocURL	http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/PiecewiseDescriptor.html
Version	1.0
arg0Desc	The breakpoint array.

Parameter List

Name	Class Type	Default Value
breakPoints	float[][][]	identity mapping on [0, 255]

See Also:

DataBuffer, ImageLayout, OperationDescriptor, Serialized Form

Field Summary

Fields inherited from class javax.media.jai.OperationDescriptorImpl

sourceNames

Fields inherited from interface javax.media.jai.OperationDescriptor

NO_PARAMETER_DEFAULT

Constructor Summary

PiecewiseDescriptor()
Constructor.

Method Summary

static RenderedOp	create(RenderedImage source0, float[][][] breakPoints, RenderingHints hints) Applies a piecewise pixel value mapping.
static RenderableOp	createRenderable(RenderableImage source0, float[][][] breakPoints, RenderingHints hints) Applies a piecewise pixel value mapping.
boolean	validateArguments(String modeName, ParameterBlock args, StringBuffer msg) Validates the input source and parameter.

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, isRenderableSupported, isRenderedSupported, makeDefaultSourceClassList, 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

PiecewiseDescriptor

public PiecewiseDescriptor()

Constructor.

Method Detail

validateArguments

public boolean validateArguments(String modeName,
                                 ParameterBlock args,
                                 StringBuffer msg)

Validates the input source and parameter.

In addition to the standard checks performed by the superclass method, this method checks that the number of bands in "breakPoints" is either 1 or the number of bands in the source image, the second breakpoint array dimension is 2, the third dimension is the same for abscissas and ordinates, and that the absicssas are monotonically increasing.

Specified by:

validateArguments in interface OperationDescriptor

Overrides:

validateArguments in class OperationDescriptorImpl

Parameters:

modeName - the operation mode name

args - Input arguments, including source(s) and/or parameter(s).

msg - A string that may contain error messages.

See Also:

OperationDescriptorImpl.validateSources(java.lang.String, java.awt.image.renderable.ParameterBlock, java.lang.StringBuffer), OperationDescriptorImpl.validateParameters(java.lang.String, java.awt.image.renderable.ParameterBlock, java.lang.StringBuffer)

create

public static RenderedOp create(RenderedImage source0,
                                float[][][] breakPoints,
                                RenderingHints hints)

Applies a piecewise pixel value mapping.

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

Parameters:

source0 - RenderedImage source 0.

breakPoints - The breakpoint array. 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,
                                            float[][][] breakPoints,
                                            RenderingHints hints)

Applies a piecewise pixel value mapping.

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

Parameters:

source0 - RenderableImage source 0.

breakPoints - The breakpoint array. 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