#include <itkMovingHistogramImageFilter.h>

Inheritance diagram for itk::MovingHistogramImageFilter< TInputImage, TOutputImage, TKernel, THistogram >:

Collaboration diagram for itk::MovingHistogramImageFilter< TInputImage, TOutputImage, TKernel, THistogram >:

Detailed Description

template<typename TInputImage, typename TOutputImage, typename TKernel, typename THistogram>
class itk::MovingHistogramImageFilter< TInputImage, TOutputImage, TKernel, THistogram >

Implements a generic moving histogram algorithm.

This filter is a base class to implement efficiently many neighborhood filters. Instead of visiting all the neighbors of a pixel, the set of pixels in the neighborhood is updated when the filter is moving to a new pixel. The number of pixels read for each pixel can be very smaller than the number of pixels read by a basic algorithm.

This filter moves the neighborhood over all the pixels of the output requested region, and pass the pixel added and removed of the neighborhood to the an histogram class. This filter doesn't implement the histogram class - it must be implement and passed as template parameter. The histogram class is not necessary a real histogram. It can be implemented in many ways, and only has to provide the methods described below.

This filter takes 4 template parameters: the input and output image type, the structuring element (or kernel) type, and the histogram type. The input and output image must have the same number of dimension.

The histogram type is a class which has to implements six methods:

a default constructor which takes no parameter.
void AddPixel( const InputPixelType &p ) is called when a new pixel is added to the histogram.
void RemovePixel( const InputPixelType &p ) is called when a pixel is removed of the histogram.
void AddBoundary() is called when a pixel outside the image is added. No value is provided: it's the responsibility to the histogram class to get it if needed. This method can be kept empty to ignore the boundary pixels.
void RemoveBoundary() is called to when a pixel outside the image is removed. No value is provided: it's the responsibility to the histogram class to get it if needed. This method can be kept empty to ignore the boundary pixels.
AType GetValue() is called to set the value of the output image. AType must be the output pixel type, or a type castable to the output pixel type.

MovingHistogramImageFilter add the new pixels before removing the old ones, so, if AddBoundary() is implemented and/or the kernel is symetric, it is safe to consider that the histogram will never be empty.

One histogram is created for each thread by the method NewHistogram(). The NewHistogram() method can be overiden to pass some parameters to the histogram.

The neighborhood is defined by a structuring element, and must a itk::Neighborhood object or a subclass. The structuring element is assumed to be composed of binary values (zero or one). Only elements of the structuring element having values > 0 are candidates for affecting the center pixel.

See Also: MovingWindowMeanImageFilter, RankImageFilter, MaskedMovingHistogramImageFilter,; MovingHistogramMorphologicalGradientImageFilter

Author: Gaetan Lehmann; Richard Beare

Definition at line 87 of file itkMovingHistogramImageFilter.h.

Public Types
typedef SmartPointer< const Self >	ConstPointer

typedef TInputImage::IndexType	IndexType

typedef TInputImage	InputImageType

typedef KernelType::ConstIterator	KernelIteratorType

typedef TKernel	KernelType

typedef std::list< OffsetType >	OffsetListType

typedef std::map< OffsetType, OffsetListType, typename OffsetType::LexicographicCompare >	OffsetMapType

typedef TInputImage::OffsetType	OffsetType

typedef Superclass::OutputImageRegionType	OutputImageRegionType

typedef TOutputImage	OutputImageType

typedef TOutputImage::PixelType	OutputPixelType

typedef TInputImage::PixelType	PixelType

typedef SmartPointer< Self >	Pointer

typedef KernelType::SizeType	RadiusType

typedef TInputImage::RegionType	RegionType

typedef MovingHistogramImageFilter	Self

typedef TInputImage::SizeType	SizeType

typedef MovingHistogramImageFilterBase < TInputImage, TOutputImage, TKernel >	Superclass

Public Types inherited from itk::MovingHistogramImageFilterBase< TInputImage, TOutputImage, TKernel >
typedef SmartPointer< const Self >	ConstPointer

typedef TInputImage::IndexType	IndexType

typedef TInputImage	InputImageType

typedef KernelType::ConstIterator	KernelIteratorType

typedef TKernel	KernelType

typedef std::list< OffsetType >	OffsetListType

typedef std::map< OffsetType, OffsetListType, typename OffsetType::LexicographicCompare >	OffsetMapType

typedef TInputImage::OffsetType	OffsetType

typedef Superclass::OutputImageRegionType	OutputImageRegionType

typedef TOutputImage	OutputImageType

typedef TOutputImage::PixelType	OutputPixelType

typedef TInputImage::PixelType	PixelType

typedef SmartPointer< Self >	Pointer

typedef KernelType::SizeType	RadiusType

typedef TInputImage::RegionType	RegionType

typedef MovingHistogramImageFilterBase	Self

typedef TInputImage::SizeType	SizeType

typedef KernelImageFilter < TInputImage, TOutputImage, TKernel >	Superclass

Public Types inherited from itk::KernelImageFilter< TInputImage, TOutputImage, TKernel >
typedef SmartPointer< const Self >	ConstPointer

typedef FlatStructuringElement < itkGetStaticConstMacro(ImageDimension) >	FlatKernelType

typedef TInputImage::IndexType	IndexType

typedef TInputImage	InputImageType

typedef TInputImage::PixelType	InputPixelType

typedef TKernel	KernelType

typedef TInputImage::OffsetType	OffsetType

typedef TOutputImage	OutputImageType

typedef TOutputImage::PixelType	OutputPixelType

typedef SmartPointer< Self >	Pointer

typedef TInputImage::SizeType	RadiusType

typedef TInputImage::RegionType	RegionType

typedef KernelImageFilter	Self

typedef TInputImage::SizeType	SizeType

typedef BoxImageFilter < TInputImage, TOutputImage >	Superclass

Public Types inherited from itk::BoxImageFilter< TInputImage, TOutputImage >
typedef SmartPointer< const Self >	ConstPointer

typedef TInputImage::IndexType	IndexType

typedef TInputImage	InputImageType

typedef TInputImage::PixelType	InputPixelType

typedef TInputImage::OffsetType	OffsetType

typedef TOutputImage	OutputImageType

typedef TOutputImage::PixelType	OutputPixelType

typedef SmartPointer< Self >	Pointer

typedef TInputImage::SizeType	RadiusType

typedef TInputImage::SizeValueType	RadiusValueType

typedef TInputImage::RegionType	RegionType

typedef BoxImageFilter	Self

typedef TInputImage::SizeType	SizeType

typedef ImageToImageFilter < TInputImage, TOutputImage >	Superclass

Public Types inherited from itk::ImageToImageFilter< TInputImage, TOutputImage >
typedef SmartPointer< const Self >	ConstPointer

typedef InputImageType::ConstPointer	InputImageConstPointer

typedef InputImageType::PixelType	InputImagePixelType

typedef InputImageType::Pointer	InputImagePointer

typedef InputImageType::RegionType	InputImageRegionType

typedef TInputImage	InputImageType

typedef Superclass::OutputImagePixelType	OutputImagePixelType

typedef Superclass::OutputImageRegionType	OutputImageRegionType

typedef SmartPointer< Self >	Pointer

typedef ImageToImageFilter	Self

typedef ImageSource< TOutputImage >	Superclass

Public Types inherited from itk::ImageSource< TOutputImage >
typedef SmartPointer< const Self >	ConstPointer

typedef Superclass::DataObjectIdentifierType	DataObjectIdentifierType

typedef DataObject::Pointer	DataObjectPointer

typedef Superclass::DataObjectPointerArraySizeType	DataObjectPointerArraySizeType

typedef OutputImageType::PixelType	OutputImagePixelType

typedef OutputImageType::Pointer	OutputImagePointer

typedef OutputImageType::RegionType	OutputImageRegionType

typedef TOutputImage	OutputImageType

typedef SmartPointer< Self >	Pointer

typedef ImageSource	Self

typedef ProcessObject	Superclass

Public Types inherited from itk::ProcessObject
typedef SmartPointer< const Self >	ConstPointer

typedef DataObject::DataObjectIdentifierType	DataObjectIdentifierType

typedef DataObject::Pointer	DataObjectPointer

typedef std::vector < DataObjectPointer >	DataObjectPointerArray

typedef DataObjectPointerArray::size_type	DataObjectPointerArraySizeType

typedef MultiThreader	MultiThreaderType

typedef std::vector < DataObjectIdentifierType >	NameArray

typedef SmartPointer< Self >	Pointer

typedef ProcessObject	Self

typedef Object	Superclass

Public Types inherited from itk::Object
typedef SmartPointer< const Self >	ConstPointer

typedef SmartPointer< Self >	Pointer

typedef Object	Self

typedef LightObject	Superclass

Public Types inherited from itk::LightObject
typedef SmartPointer< const Self >	ConstPointer

typedef SmartPointer< Self >	Pointer

typedef LightObject	Self

Public Member Functions
virtual void	ConfigureHistogram (THistogram &)

virtual ::itk::LightObject::Pointer	CreateAnother () const

virtual const char *	GetNameOfClass () const

Public Member Functions inherited from itk::MovingHistogramImageFilterBase< TInputImage, TOutputImage, TKernel >
virtual ::itk::LightObject::Pointer	CreateAnother () const

virtual SizeValueType	GetPixelsPerTranslation () const

void	SetKernel (const KernelType &kernel) override

Public Member Functions inherited from itk::KernelImageFilter< TInputImage, TOutputImage, TKernel >
virtual const KernelType &	GetKernel () const

virtual void	SetRadius (const RadiusType &radius) override

virtual void	SetRadius (const SizeValueType &radius) override

Public Member Functions inherited from itk::BoxImageFilter< TInputImage, TOutputImage >
virtual const RadiusType &	GetRadius () const

virtual void	SetRadius (const RadiusValueType &radius)

Public Member Functions inherited from itk::ImageToImageFilter< TInputImage, TOutputImage >
const InputImageType *	GetInput () const

const InputImageType *	GetInput (unsigned int idx) const

virtual void	PopBackInput () override

virtual void	PopFrontInput () override

virtual void	PushBackInput (const InputImageType *image)

virtual void	PushFrontInput (const InputImageType *image)

virtual void	SetInput (const InputImageType *image)

virtual void	SetInput (unsigned int, const TInputImage *image)

virtual void	SetCoordinateTolerance (double _arg)

virtual double	GetCoordinateTolerance () const

virtual void	SetDirectionTolerance (double _arg)

virtual double	GetDirectionTolerance () const

Public Member Functions inherited from itk::ImageSource< TOutputImage >
OutputImageType *	GetOutput (unsigned int idx)

virtual void	GraftNthOutput (unsigned int idx, DataObject *output)

virtual void	GraftOutput (const DataObjectIdentifierType &key, DataObject *output)

OutputImageType *	GetOutput ()

const OutputImageType *	GetOutput () const

virtual void	GraftOutput (DataObject *output)

virtual ProcessObject::DataObjectPointer	MakeOutput (ProcessObject::DataObjectPointerArraySizeType idx) override

virtual ProcessObject::DataObjectPointer	MakeOutput (const ProcessObject::DataObjectIdentifierType &) override

Public Member Functions inherited from itk::ProcessObject
virtual void	AbortGenerateDataOff ()

virtual void	AbortGenerateDataOn ()

virtual void	EnlargeOutputRequestedRegion (DataObject *)

virtual const bool &	GetAbortGenerateData () const

DataObjectPointerArray	GetIndexedInputs ()

DataObjectPointerArray	GetIndexedOutputs ()

NameArray	GetInputNames () const

DataObjectPointerArray	GetInputs ()

MultiThreaderType *	GetMultiThreader () const

DataObjectPointerArraySizeType	GetNumberOfIndexedInputs () const

DataObjectPointerArraySizeType	GetNumberOfIndexedOutputs () const

DataObjectPointerArraySizeType	GetNumberOfInputs () const

DataObjectPointerArraySizeType	GetNumberOfOutputs () const

virtual DataObjectPointerArraySizeType	GetNumberOfValidRequiredInputs () const

NameArray	GetOutputNames () const

DataObjectPointerArray	GetOutputs ()

virtual const float &	GetProgress () const

NameArray	GetRequiredInputNames () const

bool	HasInput (const DataObjectIdentifierType &key) const

bool	HasOutput (const DataObjectIdentifierType &key) const

virtual void	PrepareOutputs ()

virtual void	PropagateRequestedRegion (DataObject *output)

virtual void	ResetPipeline ()

virtual void	SetAbortGenerateData (bool _arg)

virtual void	Update ()

virtual void	UpdateLargestPossibleRegion ()

virtual void	UpdateOutputData (DataObject *output)

virtual void	UpdateOutputInformation ()

void	UpdateProgress (float progress)

void	SetProgress (float progress)

virtual void	SetReleaseDataFlag (bool flag)

virtual bool	GetReleaseDataFlag () const

void	ReleaseDataFlagOn ()

void	ReleaseDataFlagOff ()

virtual void	SetReleaseDataBeforeUpdateFlag (bool _arg)

virtual const bool &	GetReleaseDataBeforeUpdateFlag () const

virtual void	ReleaseDataBeforeUpdateFlagOn ()

virtual void	ReleaseDataBeforeUpdateFlagOff ()

virtual void	SetNumberOfThreads (ThreadIdType _arg)

virtual const ThreadIdType &	GetNumberOfThreads () const

Public Member Functions inherited from itk::Object
unsigned long	AddObserver (const EventObject &event, Command *)

unsigned long	AddObserver (const EventObject &event, Command *) const

virtual void	DebugOff () const

virtual void	DebugOn () const

Command *	GetCommand (unsigned long tag)

bool	GetDebug () const

MetaDataDictionary &	GetMetaDataDictionary ()

const MetaDataDictionary &	GetMetaDataDictionary () const

virtual ModifiedTimeType	GetMTime () const

virtual const TimeStamp &	GetTimeStamp () const

bool	HasObserver (const EventObject &event) const

void	InvokeEvent (const EventObject &)

void	InvokeEvent (const EventObject &) const

virtual void	Modified () const

virtual void	Register () const override

void	RemoveAllObservers ()

void	RemoveObserver (unsigned long tag)

void	SetDebug (bool debugFlag) const

void	SetMetaDataDictionary (const MetaDataDictionary &rhs)

virtual void	SetReferenceCount (int) override

virtual void	UnRegister () const noexceptoverride

virtual void	SetObjectName (std::string _arg)

virtual const std::string &	GetObjectName () const

Public Member Functions inherited from itk::LightObject
virtual void	Delete ()

virtual int	GetReferenceCount () const

	itkCloneMacro (Self)

void	Print (std::ostream &os, Indent indent=0) const

Static Public Member Functions
static Pointer	New ()

Static Public Member Functions inherited from itk::MovingHistogramImageFilterBase< TInputImage, TOutputImage, TKernel >
static Pointer	New ()

Static Public Member Functions inherited from itk::KernelImageFilter< TInputImage, TOutputImage, TKernel >
static Pointer	New ()

Static Public Member Functions inherited from itk::BoxImageFilter< TInputImage, TOutputImage >
static Pointer	New ()

Static Public Member Functions inherited from itk::Object
static bool	GetGlobalWarningDisplay ()

static void	GlobalWarningDisplayOff ()

static void	GlobalWarningDisplayOn ()

static Pointer	New ()

static void	SetGlobalWarningDisplay (bool flag)

Static Public Member Functions inherited from itk::LightObject
static void	BreakOnError ()

static Pointer	New ()

Static Public Attributes
static const unsigned int	ImageDimension = TInputImage::ImageDimension

Static Public Attributes inherited from itk::MovingHistogramImageFilterBase< TInputImage, TOutputImage, TKernel >
static const unsigned int	ImageDimension = TInputImage::ImageDimension

Static Public Attributes inherited from itk::KernelImageFilter< TInputImage, TOutputImage, TKernel >
static const unsigned int	ImageDimension = TInputImage::ImageDimension

Static Public Attributes inherited from itk::BoxImageFilter< TInputImage, TOutputImage >
static const unsigned int	ImageDimension = TInputImage::ImageDimension

Static Public Attributes inherited from itk::ImageToImageFilter< TInputImage, TOutputImage >
static const unsigned int	InputImageDimension = TInputImage::ImageDimension

static const unsigned int	OutputImageDimension = TOutputImage::ImageDimension

Static Public Attributes inherited from itk::ImageSource< TOutputImage >
static const unsigned int	OutputImageDimension = TOutputImage::ImageDimension

Protected Types
typedef THistogram	HistogramType

Protected Types inherited from itk::ImageToImageFilter< TInputImage, TOutputImage >
typedef ImageToImageFilterDetail::ImageRegionCopier < itkGetStaticConstMacro(OutputImageDimension), itkGetStaticConstMacro(InputImageDimension) >	InputToOutputRegionCopierType

typedef ImageToImageFilterDetail::ImageRegionCopier < itkGetStaticConstMacro(InputImageDimension), itkGetStaticConstMacro(OutputImageDimension) >	OutputToInputRegionCopierType

Protected Member Functions
	MovingHistogramImageFilter ()

void	PushHistogram (HistogramType &histogram, const OffsetListType addedList, const OffsetListType removedList, const RegionType &inputRegion, const RegionType &kernRegion, const InputImageType *inputImage, const IndexType currentIdx)

void	ThreadedGenerateData (const OutputImageRegionType &outputRegionForThread, ThreadIdType threadId) override

	~MovingHistogramImageFilter () override

Protected Member Functions inherited from itk::MovingHistogramImageFilterBase< TInputImage, TOutputImage, TKernel >
void	GetDirAndOffset (const IndexType LineStart, const IndexType PrevLineStart, OffsetType &LineOffset, OffsetType &Changes, int &LineDirection)

	MovingHistogramImageFilterBase ()

void	PrintSelf (std::ostream &os, Indent indent) const override

	~MovingHistogramImageFilterBase () override

Protected Member Functions inherited from itk::KernelImageFilter< TInputImage, TOutputImage, TKernel >
	KernelImageFilter ()

	~KernelImageFilter () override

Protected Member Functions inherited from itk::BoxImageFilter< TInputImage, TOutputImage >
	BoxImageFilter ()

virtual void	GenerateInputRequestedRegion () override

	~BoxImageFilter () override

Protected Member Functions inherited from itk::ImageToImageFilter< TInputImage, TOutputImage >
virtual void	CallCopyInputRegionToOutputRegion (OutputImageRegionType &destRegion, const InputImageRegionType &srcRegion)

virtual void	CallCopyOutputRegionToInputRegion (InputImageRegionType &destRegion, const OutputImageRegionType &srcRegion)

	ImageToImageFilter ()

virtual void	VerifyInputInformation () override

	~ImageToImageFilter () override

void	PushBackInput (const DataObject *input) override

void	PushFrontInput (const DataObject *input) override

Protected Member Functions inherited from itk::ImageSource< TOutputImage >
virtual void	AfterThreadedGenerateData ()

virtual void	AllocateOutputs ()

virtual void	BeforeThreadedGenerateData ()

virtual void	GenerateData () override

virtual const ImageRegionSplitterBase *	GetImageRegionSplitter () const

	ImageSource ()

virtual unsigned int	SplitRequestedRegion (unsigned int i, unsigned int pieces, OutputImageRegionType &splitRegion)

virtual	~ImageSource () override

Protected Member Functions inherited from itk::ProcessObject
virtual void	AddInput (DataObject *input)

void	AddOptionalInputName (const DataObjectIdentifierType &)

void	AddOptionalInputName (const DataObjectIdentifierType &, DataObjectPointerArraySizeType idx)

virtual void	AddOutput (DataObject *output)

bool	AddRequiredInputName (const DataObjectIdentifierType &)

bool	AddRequiredInputName (const DataObjectIdentifierType &, DataObjectPointerArraySizeType idx)

virtual void	CacheInputReleaseDataFlags ()

virtual void	GenerateOutputInformation ()

virtual void	GenerateOutputRequestedRegion (DataObject *output)

DataObject *	GetInput (const DataObjectIdentifierType &key)

const DataObject *	GetInput (const DataObjectIdentifierType &key) const

virtual const DataObjectPointerArraySizeType &	GetNumberOfRequiredInputs () const

virtual const DataObjectPointerArraySizeType &	GetNumberOfRequiredOutputs () const

bool	IsIndexedInputName (const DataObjectIdentifierType &) const

bool	IsIndexedOutputName (const DataObjectIdentifierType &) const

bool	IsRequiredInputName (const DataObjectIdentifierType &) const

	itkLegacyMacro (virtual void RemoveOutput(DataObject *output))

	itkLegacyMacro (void SetNumberOfOutputs(DataObjectPointerArraySizeType num))

	itkLegacyMacro (virtual void RemoveInput(DataObject *input))

	itkLegacyMacro (void SetNumberOfInputs(DataObjectPointerArraySizeType num))

DataObjectPointerArraySizeType	MakeIndexFromInputName (const DataObjectIdentifierType &name) const

DataObjectPointerArraySizeType	MakeIndexFromOutputName (const DataObjectIdentifierType &name) const

DataObjectIdentifierType	MakeNameFromInputIndex (DataObjectPointerArraySizeType idx) const

DataObjectIdentifierType	MakeNameFromOutputIndex (DataObjectPointerArraySizeType idx) const

	ProcessObject ()

virtual void	PropagateResetPipeline ()

virtual void	ReleaseInputs ()

virtual void	RemoveInput (const DataObjectIdentifierType &key)

virtual void	RemoveInput (DataObjectPointerArraySizeType)

virtual void	RemoveOutput (const DataObjectIdentifierType &key)

virtual void	RemoveOutput (DataObjectPointerArraySizeType idx)

bool	RemoveRequiredInputName (const DataObjectIdentifierType &)

virtual void	RestoreInputReleaseDataFlags ()

virtual void	SetInput (const DataObjectIdentifierType &key, DataObject *input)

virtual void	SetNthInput (DataObjectPointerArraySizeType num, DataObject *input)

virtual void	SetNthOutput (DataObjectPointerArraySizeType num, DataObject *output)

void	SetNumberOfIndexedInputs (DataObjectPointerArraySizeType num)

void	SetNumberOfIndexedOutputs (DataObjectPointerArraySizeType num)

virtual void	SetNumberOfRequiredInputs (DataObjectPointerArraySizeType)

virtual void	SetNumberOfRequiredOutputs (DataObjectPointerArraySizeType _arg)

virtual void	SetOutput (const DataObjectIdentifierType &key, DataObject *output)

virtual void	SetPrimaryInput (DataObject *input)

virtual void	SetPrimaryOutput (DataObject *output)

void	SetRequiredInputNames (const NameArray &)

virtual void	VerifyPreconditions ()

	~ProcessObject () override

DataObject *	GetInput (DataObjectPointerArraySizeType idx)

const DataObject *	GetInput (DataObjectPointerArraySizeType idx) const

DataObject *	GetPrimaryInput ()

const DataObject *	GetPrimaryInput () const

virtual void	SetPrimaryInputName (const DataObjectIdentifierType &key)

virtual const char *	GetPrimaryInputName (void) const

DataObject *	GetOutput (const DataObjectIdentifierType &key)

const DataObject *	GetOutput (const DataObjectIdentifierType &key) const

virtual void	SetPrimaryOutputName (const DataObjectIdentifierType &key)

virtual const char *	GetPrimaryOutputName (void) const

DataObject *	GetOutput (DataObjectPointerArraySizeType idx)

const DataObject *	GetOutput (DataObjectPointerArraySizeType idx) const

DataObject *	GetPrimaryOutput ()

const DataObject *	GetPrimaryOutput () const

Protected Member Functions inherited from itk::Object
	Object ()

bool	PrintObservers (std::ostream &os, Indent indent) const

virtual void	SetTimeStamp (const TimeStamp &time)

virtual	~Object () override

Protected Member Functions inherited from itk::LightObject
virtual LightObject::Pointer	InternalClone () const

	LightObject ()

virtual void	PrintHeader (std::ostream &os, Indent indent) const

virtual void	PrintTrailer (std::ostream &os, Indent indent) const

virtual	~LightObject ()

Additional Inherited Members
Static Protected Member Functions inherited from itk::ImageSource< TOutputImage >
static const ImageRegionSplitterBase *	GetGlobalDefaultSplitter ()

static ITK_THREAD_RETURN_TYPE	ThreaderCallback (void *arg)

Protected Attributes inherited from itk::MovingHistogramImageFilterBase< TInputImage, TOutputImage, TKernel >
OffsetMapType	m_AddedOffsets

FixedArray< int, itkGetStaticConstMacro(ImageDimension) >	m_Axes

OffsetListType	m_KernelOffsets

SizeValueType	m_PixelsPerTranslation

OffsetMapType	m_RemovedOffsets

Protected Attributes inherited from itk::KernelImageFilter< TInputImage, TOutputImage, TKernel >
KernelType	m_Kernel

Protected Attributes inherited from itk::ProcessObject
TimeStamp	m_OutputInformationMTime

bool	m_Updating

Protected Attributes inherited from itk::LightObject
AtomicInt< int >	m_ReferenceCount