javax.media.jai.operator
Class OverlayDescriptor

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

All Implemented Interfaces:

OperationDescriptor, RegistryElementDescriptor, Serializable

public class OverlayDescriptor

extends OperationDescriptorImpl

An OperationDescriptor describing the "Overlay" operation.

The Overlay operation takes two rendered or renderable source images, and overlays the second source image on top of the first source image. No additional parameters are required.

The two source images must have the same data type and number of bands. However, their SampleModel types may differ. The destination image will always have the same bounding rectangle as the first source image, that is, the image on the bottom, and the same data type and number of bands as the two sources. In case the two sources don't intersect, the destination will be the same as the first source.

The destination pixel values are defined by the pseudocode:

 if (srcs[1] contains the point (x, y)) {
     dst[x][y][b] = srcs[1][x][y][b];
 } else {
     dst[x][y][b] = srcs[0][x][y][b];
 }
 

Resource List

Name	Value
GlobalName	Overlay
LocalName	Overlay
Vendor	com.sun.media.jai
Description	Overlays one rendered image on top of another.
DocURL	http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/OverlayDescriptor.html
Version	1.0

No parameters are needed for this operation.

See Also:

OperationDescriptor, Serialized Form

Fields inherited from class javax.media.jai.OperationDescriptorImpl

resources, sourceNames, supportedModes

Constructor Summary

OverlayDescriptor()
Constructor.

Method Summary

protected boolean

validateSources(String modeName, ParameterBlock args, StringBuffer msg) Validates the input sources.

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, validateArguments, validateParameters, validateParameters, validateRenderableArguments, validateRenderableSources, validateSources

Methods inherited from class java.lang.Object

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

Constructor Detail

OverlayDescriptor

public OverlayDescriptor()

Constructor.

Method Detail

validateSources

protected boolean validateSources(String modeName,
                                  ParameterBlock args,
                                  StringBuffer msg)

Validates the input sources.

In addition to the standard checks performed by the superclass method, this method checks that the source image SampleModels have the same number of bands and transfer types.

Overrides:

validateSources in class OperationDescriptorImpl

Tags copied from class: OperationDescriptorImpl

Parameters:

modeName - the operation mode name

args - a ParameterBlock that has the sources

msg - A string that may contain error messages.

Throws:

IllegalArgumentException - if any of the input parameters are null.

See Also:

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