jaitools.media.jai.maskedconvolve
Class MaskedConvolveDescriptor

java.lang.Object
  javax.media.jai.OperationDescriptorImpl
      jaitools.media.jai.maskedconvolve.MaskedConvolveDescriptor

All Implemented Interfaces:

Serializable, javax.media.jai.OperationDescriptor, javax.media.jai.RegistryElementDescriptor

public class MaskedConvolveDescriptor
extends javax.media.jai.OperationDescriptorImpl

An OperationDescriptor describing the "MaskedConvolve" operation. This is a variant of JAI's convolve operator which constrains the convolution to pixels that are included in an ROI.

Two masking options are provided:

• source masking, in which the ROI is used to constrain which source image pixels contribute to the kernel calculation;
• destination masking in which the ROI constrains the positioning of the convolution kernel such that destination image value will be 0 if a source pixel is not contained in the ROI.

The two options may be used together. If neither masking option is required it is prefereable to use the "Convolve" operator for faster processing.

If there is no convolution result for a destination image pixel, either because it was not included in a destination mask or had no kernel values included in a source mask, it will be set to a flag value. This can be set using the nilValue parameter (default is 0).

Since:

1.0

Version:

$Id: MaskedConvolveDescriptor.java 1383 2011-02-10 11:22:29Z michael.bedward $

Author:

Michael Bedward

See Also:

ConvolveDescriptor, Serialized Form

Field Summary

static Number	DEFAULT_NIL_VALUE Default value for nilValue parameter (0)
static String	MIN_CELLS_ALL Constant that can be used for the minCells parameter to require all non-zero kernel cells to overlap with unmasked source image cells for convolution to be performed for a terget cell
static String	MIN_CELLS_ANY Constant that can be used for the minCells parameter to specify convolution will be performed for a terget cell if any non-zero kernel cells overlap with unmasked source image cells.

Fields inherited from class javax.media.jai.OperationDescriptorImpl

resources, sourceNames, supportedModes

Fields inherited from interface javax.media.jai.OperationDescriptor

NO_PARAMETER_DEFAULT

Constructor Summary

MaskedConvolveDescriptor()
Constructor.

Method Summary

static javax.media.jai.RenderedOp	create(RenderedImage source0, javax.media.jai.KernelJAI kernel, javax.media.jai.ROI roi, Boolean maskSource, Boolean maskDest, Number nilValue, int minCells, RenderingHints hints) Constructs a ParameterBlockJAI and invokes JAI.create("maskedconvolve", params) .
protected boolean	validateParameters(String modeName, ParameterBlock pb, StringBuffer msg)

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, validateRenderableArguments, validateRenderableSources, validateSources, validateSources

Methods inherited from class java.lang.Object

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

Field Detail

MIN_CELLS_ANY

public static final String MIN_CELLS_ANY

Constant that can be used for the minCells parameter to specify convolution will be performed for a terget cell if any non-zero kernel cells overlap with unmasked source image cells. This is the default parameter value.

See Also:

Constant Field Values

MIN_CELLS_ALL

public static final String MIN_CELLS_ALL

Constant that can be used for the minCells parameter to require all non-zero kernel cells to overlap with unmasked source image cells for convolution to be performed for a terget cell

See Also:

Constant Field Values

DEFAULT_NIL_VALUE

public static final Number DEFAULT_NIL_VALUE

Default value for nilValue parameter (0)

Constructor Detail

MaskedConvolveDescriptor

public MaskedConvolveDescriptor()

Constructor.

Method Detail

create

public static javax.media.jai.RenderedOp create(RenderedImage source0,
                                                javax.media.jai.KernelJAI kernel,
                                                javax.media.jai.ROI roi,
                                                Boolean maskSource,
                                                Boolean maskDest,
                                                Number nilValue,
                                                int minCells,
                                                RenderingHints hints)

Constructs a ParameterBlockJAI and invokes JAI.create("maskedconvolve", params) .

Note: with this method only integer values can be passed for the minCells argument. To use the Strings "ANY" or "ALL" or the constants described in the class docs use the JAI.create method with a parameter block rather than this method.

Parameters:

source0 - the image to be convolved

kernel - convolution kernel

roi - the roi controlling convolution (must have the same pixel bounds as the source image)

maskSource - if TRUE only the values of source pixels where roi.contains is true contribute to the convolution

maskDest - if TRUE convolution is only performed for pixels where roi.contains is true

nilValue - value to write to the destination image for pixels where there is no convolution result

minCells - the minimum number of non-zero kernel cells that be positioned over unmasked source image cells for convolution to be performed for the target cell

hints - useful for specifying a border extender; may be null

Returns:

the RenderedOp destination

Throws:

IllegalArgumentException - if any args are null

validateParameters

protected boolean validateParameters(String modeName,
                                     ParameterBlock pb,
                                     StringBuffer msg)

Overrides:

validateParameters in class javax.media.jai.OperationDescriptorImpl