javax.media.jai.operator
Class ThresholdDescriptor

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

public class ThresholdDescriptor

extends OperationDescriptorImpl

An OperationDescriptor describing the "Threshold" operation.

The Threshold operation takes one rendered image, and maps all the pixels of this image whose value falls within a specified range to a specified constant. The range is specified by a low value and a high value.

If the number of elements supplied via the "high", "low", and "constants" arrays are less than the number of bands of the source image, then the element from entry 0 is applied to all the bands. Otherwise, the element from a different entry is applied to its corresponding band.

The destination pixel values are defined by the pseudocode:

 lowVal = (low.length < dstNumBands) ?
          low[0] : low[b];
 highVal = (high.length < dstNumBands) ?
           high[0] : high[b];
 const = (constants.length < dstNumBands) ?
           constants[0] : constants[b];

 if (src[x][y][b] >= lowVal && src[x][y][b] <= highVal) {
     dst[x][y][b] = const;
 } else {
     dst[x][y][b] = src[x][y][b];
 }
 

Resource List

Name	Value
GlobalName	Threshold
LocalName	Threshold
Vendor	com.sun.media.jai
Description	Maps the pixels whose value falls between a low value and a high value to a constant.
DocURL	http://java.sun.com/products/java-media/jai/forDevelopers/jaiapi/ javax.media.jai.operator.ThresholdDescriptor.html
Version	1.0
arg0Desc	The low value.
arg1Desc	The high value.
arg2Desc	The constant the pixels are mapped to.

Parameter List

Name	Class Type	Default Value
low	double[]	NO_PARAMETER_DEFAULT
high	double[]	NO_PARAMETER_DEFAULT
constants	double[]	NO_PARAMETER_DEFAULT

See Also:

OperationDescriptor

Fields inherited from class javax.media.jai.OperationDescriptorImpl

paramClasses, paramDefaults, paramNames, renderableSourceClasses, resources, sourceClasses

Constructor Summary

ThresholdDescriptor()
Constructor.

Method Summary

boolean	isRenderableSupported() Returns true since renderable operation is supported.
protected boolean	validateParameters(java.awt.image.renderable.ParameterBlock args, java.lang.StringBuffer msg) Validates input parameters.

Methods inherited from class javax.media.jai.OperationDescriptorImpl

getDestClass, getName, getNumParameters, getNumSources, getParamClasses, getParamDefaults, getParamDefaultValue, getParamMaxValue, getParamMinValue, getParamNames, getPropertyGenerators, getRenderableDestClass, getRenderableSourceClasses, getResourceBundle, getResources, getSourceClasses, isImmediate, isRenderedSupported, validateArguments, validateRenderableArguments, validateRenderableSources, validateSources

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ThresholdDescriptor

public ThresholdDescriptor()

Constructor.

Method Detail

isRenderableSupported

public boolean isRenderableSupported()

Returns true since renderable operation is supported.

Overrides:

isRenderableSupported in class OperationDescriptorImpl

validateParameters

protected boolean validateParameters(java.awt.image.renderable.ParameterBlock args,
                                     java.lang.StringBuffer msg)

Validates input parameters.

Overrides:

validateParameters in class OperationDescriptorImpl