#include <itkRegionFromReferenceLabelMapFilter.h>

Detailed Description

template<typename TInputImage>
class itk::RegionFromReferenceLabelMapFilter< TInputImage >

Set the region from a reference image.

Change the region of a label map to be the same as one of a reference image. This filter implements the same feature as its superclass, but with the input region well integrated in the pipeline architecture. If the output cannot contain some of the objects' lines, they are truncated or removed. All objects fully outside the output region are removed.

This implementation was taken from the Insight Journal paper: https://doi.org/10.54294/q6auw4

Author: Gaetan Lehmann. Biologie du Developpement et de la Reproduction, INRA de Jouy-en-Josas, France.

Definition at line 54 of file itkRegionFromReferenceLabelMapFilter.h.

Inheritance diagram for itk::RegionFromReferenceLabelMapFilter< TInputImage >:

Collaboration diagram for itk::RegionFromReferenceLabelMapFilter< TInputImage >:

Public Types
using	ConstPointer = SmartPointer< const Self >

using	IndexType = typename InputImageType::IndexType

using	InputImageConstPointer = typename InputImageType::ConstPointer

using	InputImagePixelType = typename InputImageType::PixelType

using	InputImagePointer = typename InputImageType::Pointer

using	InputImageRegionType = typename InputImageType::RegionType

using	InputImageType = TInputImage

using	LabelObjectType = typename InputImageType::LabelObjectType

using	PixelType = typename InputImageType::PixelType

using	Pointer = SmartPointer< Self >

using	ReferenceImageType = ImageBase< Self::ImageDimension >

using	RegionType = typename InputImageType::RegionType

using	Self = RegionFromReferenceLabelMapFilter

using	SizeType = typename InputImageType::SizeType

using	Superclass = ChangeRegionLabelMapFilter< TInputImage >

using	TOutputImage = TInputImage

Public Types inherited from itk::ChangeRegionLabelMapFilter< TInputImage >
using	ConstPointer = SmartPointer< const Self >

using	IndexType = typename InputImageType::IndexType

using	IndexValueType = typename InputImageType::IndexValueType

using	InputImageConstPointer = typename InputImageType::ConstPointer

using	InputImagePixelType = typename InputImageType::PixelType

using	InputImagePointer = typename InputImageType::Pointer

using	InputImageRegionType = typename InputImageType::RegionType

using	InputImageType = TInputImage

using	LabelObjectType = typename InputImageType::LabelObjectType

using	PixelType = typename InputImageType::PixelType

using	Pointer = SmartPointer< Self >

using	RegionType = typename InputImageType::RegionType

using	Self = ChangeRegionLabelMapFilter

using	SizeType = typename InputImageType::SizeType

using	Superclass = InPlaceLabelMapFilter< TInputImage >

using	TOutputImage = TInputImage

Public Types inherited from itk::InPlaceLabelMapFilter< TInputImage >
using	ConstPointer = SmartPointer< const Self >

using	IndexType = typename InputImageType::IndexType

using	InputImageConstPointer = typename InputImageType::ConstPointer

using	InputImagePixelType = typename InputImageType::PixelType

using	InputImagePointer = typename InputImageType::Pointer

using	InputImageRegionType = typename InputImageType::RegionType

using	InputImageType = TInputImage

using	LabelObjectType = typename InputImageType::LabelObjectType

using	PixelType = typename InputImageType::PixelType

using	Pointer = SmartPointer< Self >

using	RegionType = typename InputImageType::RegionType

using	Self = InPlaceLabelMapFilter

using	Superclass = LabelMapFilter< TInputImage, TInputImage >

using	TOutputImage = TInputImage

Public Types inherited from itk::LabelMapFilter< TInputImage, TInputImage >
using	ConstPointer = SmartPointer< const Self >

using	LabelObjectType = typename InputImageType::LabelObjectType

using	OutputImageConstPointer = typename OutputImageType::ConstPointer

using	OutputImagePixelType = typename OutputImageType::PixelType

using	OutputImagePointer = typename OutputImageType::Pointer

using	OutputImageRegionType = typename OutputImageType::RegionType

using	OutputImageType = TInputImage

using	Pointer = SmartPointer< Self >

using	Self = LabelMapFilter

using	Superclass = ImageToImageFilter< TInputImage, TInputImage >

Public Types inherited from itk::ImageToImageFilter< TInputImage, TInputImage >
using	ConstPointer = SmartPointer< const Self >

using	InputImageConstPointer = typename InputImageType::ConstPointer

using	InputImagePixelType = typename InputImageType::PixelType

using	InputImagePointer = typename InputImageType::Pointer

using	InputImageRegionType = typename InputImageType::RegionType

using	InputImageType = TInputImage

using	Pointer = SmartPointer< Self >

using	Self = ImageToImageFilter

using	Superclass = ImageSource< TInputImage >

Public Types inherited from itk::ImageSource< TInputImage >
using	ConstPointer = SmartPointer< const Self >

using	DataObjectIdentifierType = Superclass::DataObjectIdentifierType

using	DataObjectPointer = DataObject::Pointer

using	DataObjectPointerArraySizeType = Superclass::DataObjectPointerArraySizeType

using	OutputImagePixelType = typename OutputImageType::PixelType

using	OutputImagePointer = typename OutputImageType::Pointer

using	OutputImageRegionType = typename OutputImageType::RegionType

using	OutputImageType = TInputImage

using	Pointer = SmartPointer< Self >

using	Self = ImageSource

using	Superclass = ProcessObject

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

using	DataObjectIdentifierType = DataObject::DataObjectIdentifierType

using	DataObjectPointer = DataObject::Pointer

using	DataObjectPointerArray = std::vector< DataObjectPointer >

using	DataObjectPointerArraySizeType = DataObjectPointerArray::size_type

using	MultiThreaderType = MultiThreaderBase

using	NameArray = std::vector< DataObjectIdentifierType >

using	Pointer = SmartPointer< Self >

using	Self = ProcessObject

using	Superclass = Object

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

using	Pointer = SmartPointer< Self >

using	Self = Object

using	Superclass = LightObject

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

using	Pointer = SmartPointer< Self >

using	Self = LightObject

Public Member Functions
const char *	GetNameOfClass () const override

const ReferenceImageType *	GetReferenceImage () const

void	SetInput1 (const TInputImage *input)

void	SetInput2 (const ReferenceImageType *input)

void	SetReferenceImage (const ReferenceImageType *image)

Public Member Functions inherited from itk::ChangeRegionLabelMapFilter< TInputImage >
const char *	GetNameOfClass () const override

virtual void	SetRegion (OutputImageRegionType _arg)

virtual const OutputImageRegionType &	GetRegion () const

Public Member Functions inherited from itk::InPlaceLabelMapFilter< TInputImage >
bool	CanRunInPlace () const

const char *	GetNameOfClass () const override

virtual void	SetInPlace (bool _arg)

virtual bool	GetInPlace ()

virtual void	InPlaceOn ()

Public Member Functions inherited from itk::LabelMapFilter< TInputImage, TInputImage >
void	EnlargeOutputRequestedRegion (DataObject *) override

void	GenerateInputRequestedRegion () override

const char *	GetNameOfClass () const override

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

const InputImageType *	GetInput (unsigned int idx) const

const char *	GetNameOfClass () const override

void	PopBackInput () override

void	PopFrontInput () override

virtual void	PushBackInput (const InputImageType *input)

virtual void	PushFrontInput (const InputImageType *input)

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

virtual void	SetInput (const InputImageType *input)

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< TInputImage >
const char *	GetNameOfClass () const override

OutputImageType *	GetOutput (unsigned int idx)

OutputImageType *	GetOutput ()

const OutputImageType *	GetOutput () const

virtual void	GraftOutput (DataObject *graft)

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

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

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

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

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

virtual void	EnlargeOutputRequestedRegion (DataObject *)

virtual const bool &	GetAbortGenerateData () const

DataObjectPointerArray	GetIndexedInputs ()

DataObjectPointerArray	GetIndexedOutputs ()

NameArray	GetInputNames () const

DataObjectPointerArray	GetInputs ()

MultiThreaderType *	GetMultiThreader () const

const char *	GetNameOfClass () const override

DataObjectPointerArraySizeType	GetNumberOfIndexedInputs () const

DataObjectPointerArraySizeType	GetNumberOfIndexedOutputs () const

DataObjectPointerArraySizeType	GetNumberOfInputs () const

DataObjectPointerArraySizeType	GetNumberOfOutputs () const

virtual DataObjectPointerArraySizeType	GetNumberOfValidRequiredInputs () const

NameArray	GetOutputNames () const

DataObjectPointerArray	GetOutputs ()

virtual float	GetProgress () const

NameArray	GetRequiredInputNames () const

bool	HasInput (const DataObjectIdentifierType &key) const

bool	HasOutput (const DataObjectIdentifierType &key) const

void	IncrementProgress (float increment)

virtual DataObjectPointer	MakeOutput (const DataObjectIdentifierType &)

virtual DataObjectPointer	MakeOutput (DataObjectPointerArraySizeType idx)

virtual void	PrepareOutputs ()

virtual void	PropagateRequestedRegion (DataObject *output)

virtual void	ResetPipeline ()

virtual void	SetAbortGenerateData (bool _arg)

void	SetMultiThreader (MultiThreaderType *threader)

virtual void	Update ()

virtual void	UpdateLargestPossibleRegion ()

virtual void	UpdateOutputData (DataObject *output)

virtual void	UpdateOutputInformation ()

void	UpdateProgress (float progress)

virtual void	SetReleaseDataFlag (bool val)

virtual bool	GetReleaseDataFlag () const

void	ReleaseDataFlagOn ()

void	ReleaseDataFlagOff ()

virtual void	SetReleaseDataBeforeUpdateFlag (bool _arg)

virtual const bool &	GetReleaseDataBeforeUpdateFlag () const

virtual void	ReleaseDataBeforeUpdateFlagOn ()

virtual void	SetNumberOfWorkUnits (ThreadIdType _arg)

virtual const ThreadIdType &	GetNumberOfWorkUnits () const

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

unsigned long	AddObserver (const EventObject &event, std::function< void(const EventObject &)> function) const

LightObject::Pointer	CreateAnother () const override

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

const char *	GetNameOfClass () const override

virtual const TimeStamp &	GetTimeStamp () const

bool	HasObserver (const EventObject &event) const

void	InvokeEvent (const EventObject &)

void	InvokeEvent (const EventObject &) const

virtual void	Modified () const

void	Register () const override

void	RemoveAllObservers ()

void	RemoveObserver (unsigned long tag) const

void	SetDebug (bool debugFlag) const

void	SetReferenceCount (int) override

void	UnRegister () const noexcept override

void	SetMetaDataDictionary (const MetaDataDictionary &rhs)

void	SetMetaDataDictionary (MetaDataDictionary &&rrhs)

virtual void	SetObjectName (std::string _arg)

virtual const std::string &	GetObjectName () const

Public Member Functions inherited from itk::LightObject
Pointer	Clone () const

virtual Pointer	CreateAnother () const

virtual void	Delete ()

virtual const char *	GetNameOfClass () const

virtual int	GetReferenceCount () const

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

virtual void	Register () const

virtual void	SetReferenceCount (int)

virtual void	UnRegister () const noexcept

Static Public Member Functions
static Pointer	New ()

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

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

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

Static Public Member Functions inherited from itk::ImageToImageFilter< TInputImage, TInputImage >
static double	GetGlobalDefaultCoordinateTolerance ()

static double	GetGlobalDefaultDirectionTolerance ()

static void	SetGlobalDefaultCoordinateTolerance (double)

static void	SetGlobalDefaultDirectionTolerance (double)

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

static void	GlobalWarningDisplayOff ()

static void	GlobalWarningDisplayOn ()

static Pointer	New ()

static void	SetGlobalWarningDisplay (bool val)

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

static Pointer	New ()

Static Public Attributes
static constexpr unsigned int	ImageDimension = TOutputImage::ImageDimension

static constexpr unsigned int	InputImageDimension = TInputImage::ImageDimension

static constexpr unsigned int	OutputImageDimension = TOutputImage::ImageDimension

Static Public Attributes inherited from itk::ChangeRegionLabelMapFilter< TInputImage >
static constexpr unsigned int	ImageDimension = TOutputImage::ImageDimension

static constexpr unsigned int	InputImageDimension = TInputImage::ImageDimension

static constexpr unsigned int	OutputImageDimension = TOutputImage::ImageDimension

Static Public Attributes inherited from itk::InPlaceLabelMapFilter< TInputImage >
static constexpr unsigned int	InputImageDimension = TInputImage::ImageDimension

static constexpr unsigned int	OutputImageDimension = TOutputImage::ImageDimension

Static Public Attributes inherited from itk::LabelMapFilter< TInputImage, TInputImage >
static constexpr unsigned int	InputImageDimension

static constexpr unsigned int	OutputImageDimension

Static Public Attributes inherited from itk::ImageToImageFilter< TInputImage, TInputImage >
static constexpr unsigned int	InputImageDimension

static constexpr unsigned int	OutputImageDimension

Static Public Attributes inherited from itk::ImageSource< TInputImage >
static constexpr unsigned int	OutputImageDimension

Protected Member Functions
void	GenerateOutputInformation () override

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

	RegionFromReferenceLabelMapFilter ()

	~RegionFromReferenceLabelMapFilter () override=default

Protected Member Functions inherited from itk::ChangeRegionLabelMapFilter< TInputImage >
	ChangeRegionLabelMapFilter ()=default

void	EnlargeOutputRequestedRegion (DataObject *) override

void	GenerateData () override

void	GenerateInputRequestedRegion () override

void	GenerateOutputInformation () override

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

void	ThreadedProcessLabelObject (LabelObjectType *labelObject) override

	~ChangeRegionLabelMapFilter () override=default

Protected Member Functions inherited from itk::InPlaceLabelMapFilter< TInputImage >
void	AllocateOutputs () override

InputImageType *	GetLabelMap () override

	InPlaceLabelMapFilter ()=default

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

	~InPlaceLabelMapFilter () override=default

Protected Member Functions inherited from itk::LabelMapFilter< TInputImage, TInputImage >
void	AfterThreadedGenerateData () override

void	BeforeThreadedGenerateData () override

void	DynamicThreadedGenerateData (const OutputImageRegionType &outputRegionForThread) override

virtual InputImageType *	GetLabelMap ()

	LabelMapFilter ()

void	ThreadedGenerateData (const OutputImageRegionType &outputRegionForThread, ThreadIdType) override

virtual void	ThreadedProcessLabelObject (LabelObjectType *labelObject)

	~LabelMapFilter () override=default

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

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

void	GenerateInputRequestedRegion () override

	ImageToImageFilter ()

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

void	VerifyInputInformation () const override

	~ImageToImageFilter () override=default

virtual void	PushBackInput (const DataObject *input)

virtual void	PushFrontInput (const DataObject *input)

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

virtual void	AllocateOutputs ()

virtual void	BeforeThreadedGenerateData ()

void	ClassicMultiThread (ThreadFunctionType callbackFunction)

void	GenerateData () override

virtual const ImageRegionSplitterBase *	GetImageRegionSplitter () const

	ImageSource ()

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

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

	~ImageSource () override=default

virtual bool	GetDynamicMultiThreading () const

virtual void	SetDynamicMultiThreading (bool _arg)

virtual void	DynamicMultiThreadingOn ()

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	GenerateData ()

virtual void	GenerateInputRequestedRegion ()

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

DataObjectPointerArraySizeType	MakeIndexFromInputName (const DataObjectIdentifierType &name) const

DataObjectPointerArraySizeType	MakeIndexFromOutputName (const DataObjectIdentifierType &name) const

DataObjectIdentifierType	MakeNameFromInputIndex (DataObjectPointerArraySizeType idx) const

DataObjectIdentifierType	MakeNameFromOutputIndex (DataObjectPointerArraySizeType idx) const

virtual void	PopBackInput ()

virtual void	PopFrontInput ()

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

	ProcessObject ()

virtual void	PropagateResetPipeline ()

virtual void	PushBackInput (const DataObject *input)

virtual void	PushFrontInput (const DataObject *input)

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 idx, DataObject *input)

virtual void	SetNthOutput (DataObjectPointerArraySizeType idx, DataObject *output)

void	SetNumberOfIndexedInputs (DataObjectPointerArraySizeType num)

void	SetNumberOfIndexedOutputs (DataObjectPointerArraySizeType num)

virtual void	SetNumberOfRequiredInputs (DataObjectPointerArraySizeType)

virtual void	SetNumberOfRequiredOutputs (DataObjectPointerArraySizeType _arg)

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

virtual void	SetPrimaryInput (DataObject *object)

virtual void	SetPrimaryOutput (DataObject *object)

void	SetRequiredInputNames (const NameArray &)

virtual void	VerifyInputInformation () const

virtual void	VerifyPreconditions () const

	~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 () const

DataObject *	GetOutput (const DataObjectIdentifierType &key)

const DataObject *	GetOutput (const DataObjectIdentifierType &key) const

virtual void	SetPrimaryOutputName (const DataObjectIdentifierType &key)

virtual const char *	GetPrimaryOutputName () const

DataObject *	GetOutput (DataObjectPointerArraySizeType i)

const DataObject *	GetOutput (DataObjectPointerArraySizeType i) const

DataObject *	GetPrimaryOutput ()

const DataObject *	GetPrimaryOutput () const

virtual bool	GetThreaderUpdateProgress () const

virtual void	ThreaderUpdateProgressOn ()

virtual void	SetThreaderUpdateProgress (bool arg)

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

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

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

virtual void	SetTimeStamp (const TimeStamp &timeStamp)

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

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

virtual	~LightObject ()

Additional Inherited Members
Protected Types inherited from itk::ImageToImageFilter< TInputImage, TInputImage >
using	InputToOutputRegionCopierType = ImageToImageFilterDetail::ImageRegionCopier< Self::OutputImageDimension, Self::InputImageDimension >

using	OutputToInputRegionCopierType = ImageToImageFilterDetail::ImageRegionCopier< Self::InputImageDimension, Self::OutputImageDimension >

Static Protected Member Functions inherited from itk::ImageSource< TInputImage >
static const ImageRegionSplitterBase *	GetGlobalDefaultSplitter ()

static ITK_THREAD_RETURN_FUNCTION_CALL_CONVENTION	ThreaderCallback (void *arg)

Static Protected Member Functions inherited from itk::ProcessObject
template<typename TSourceObject >
static void	MakeRequiredOutputs (TSourceObject &sourceObject, const DataObjectPointerArraySizeType numberOfRequiredOutputs)

static constexpr float	progressFixedToFloat (uint32_t fixed)

static uint32_t	progressFloatToFixed (float f)

Protected Attributes inherited from itk::LabelMapFilter< TInputImage, TInputImage >
std::mutex	m_LabelObjectContainerLock

Protected Attributes inherited from itk::ImageSource< TInputImage >
bool	m_DynamicMultiThreading

Protected Attributes inherited from itk::ProcessObject
TimeStamp	m_OutputInformationMTime {}

bool	m_Updating {}

Protected Attributes inherited from itk::LightObject
std::atomic< int >	m_ReferenceCount {}