#include <itkFiniteDifferenceFunction.h>

Inheritance diagram for itk::FiniteDifferenceFunction< TImageType >:

Collaboration diagram for itk::FiniteDifferenceFunction< TImageType >:

Public Types
typedef SmartPointer< const Self >	ConstPointer
typedef ZeroFluxNeumannBoundaryCondition < ImageType >	DefaultBoundaryConditionType
typedef Vector< float, itkGetStaticConstMacro(ImageDimension)>	FloatOffsetType
typedef TImageType	ImageType
typedef Vector< PixelRealType, itkGetStaticConstMacro(ImageDimension)>	NeighborhoodScalesType
typedef ConstNeighborhoodIterator < TImageType, DefaultBoundaryConditionType >	NeighborhoodType
typedef double	PixelRealType
typedef ImageType::PixelType	PixelType
typedef SmartPointer< Self >	Pointer
typedef ConstNeighborhoodIterator < TImageType >::RadiusType	RadiusType
typedef FiniteDifferenceFunction	Self
typedef LightObject	Superclass
typedef double	TimeStepType
Public Member Functions
virtual TimeStepType	ComputeGlobalTimeStep (void *GlobalData) const =0
const NeighborhoodScalesType	ComputeNeighborhoodScales () const
virtual PixelType	ComputeUpdate (const NeighborhoodType &neighborhood, void *globalData, const FloatOffsetType &offset=FloatOffsetType(0.0))=0
virtual Pointer	CreateAnother () const
virtual void	Delete ()
virtual void *	GetGlobalDataPointer () const =0
virtual const char *	GetNameOfClass () const
const RadiusType &	GetRadius () const
virtual int	GetReferenceCount () const
virtual void	InitializeIteration ()
void	Print (std::ostream &os, Indent indent=0) const
virtual void	Register () const
virtual void	ReleaseGlobalDataPointer (void *GlobalData) const =0
void	SetRadius (const RadiusType &r)
virtual void	SetReferenceCount (int)
virtual void	UnRegister () const


void	SetScaleCoefficients (PixelRealType vals[ImageDimension])
Static Public Member Functions
static void	BreakOnError ()
static Pointer	New ()
Static Public Attributes
static const unsigned int	ImageDimension = ImageType::ImageDimension
Protected Types


typedef int	InternalReferenceCountType
Protected Member Functions
	FiniteDifferenceFunction ()
void	PrintSelf (std::ostream &os, Indent indent) const
	~FiniteDifferenceFunction ()


virtual void	PrintHeader (std::ostream &os, Indent indent) const
virtual void	PrintTrailer (std::ostream &os, Indent indent) const
Protected Attributes
RadiusType	m_Radius
InternalReferenceCountType	m_ReferenceCount
SimpleFastMutexLock	m_ReferenceCountLock
PixelRealType	m_ScaleCoefficients [ImageDimension]

Detailed Description

template<class TImageType>
class itk::FiniteDifferenceFunction< TImageType >

This class is a component object of the finite difference solver hierarchy (see itkFiniteDifferenceImageFilter). It defines a generic interface for a function object that computes a single scalar value from a neighborhood of values. Examples of the application of this class are the various flavors of AnisotropicDiffusionFunctions and LevelSetFunction objects.

These functions calculate the incremental change at a pixel in the solution image from one iteration of the p.d.e. solver to the next.

: Subclasses of FiniteDifferenceImageFilter (solvers) call the ComputeUpdate() method of this class to compute $\Delta u^n_{\mathbf{i}}$ at each . in . Because the size of the time step for each iteration of the p.d.e. solution depends on the particular calculations done, this function object is also responsible for computing that time step (see ComputeGlobalTimeStep).

How to use this class: FiniteDifferenceFunction must be subclassed to add functionality for ComputeUpdate, ComputeGlobalTimeStep, and Get/ReleaseGlobalDataPointer.

A note on thread safety.: template<class TImageType> The ComputeUpdate() methods of this filter are declared as const to enforce thread-safety during execution of FiniteDifferenceImageFilter solver algorithms. The InitializeIteration() method is intended to provide a safe way to modify the state of the object between threaded calculations of solvers.

Todo:: Possibly subclass this object from Function. Stumbling blocks here are the specialized api of FiniteDifferenceFunction.

Definition at line 65 of file itkFiniteDifferenceFunction.h.

Member Typedef Documentation

template<class TImageType>

typedef SmartPointer<const Self> itk::FiniteDifferenceFunction< TImageType >::ConstPointer

Reimplemented from itk::LightObject.

Definition at line 73 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef ZeroFluxNeumannBoundaryCondition<ImageType> itk::FiniteDifferenceFunction< TImageType >::DefaultBoundaryConditionType

The default boundary condition for finite difference functions that is used unless overridden in the Evaluate() method.

Definition at line 92 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef Vector<float,itkGetStaticConstMacro(ImageDimension)> itk::FiniteDifferenceFunction< TImageType >::FloatOffsetType

A floating point offset from an image grid location. Used for interpolation among grid values in a neighborhood.

Definition at line 107 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef TImageType itk::FiniteDifferenceFunction< TImageType >::ImageType

Extract some parameters from the image type

Definition at line 76 of file itkFiniteDifferenceFunction.h.

typedef int itk::LightObject::InternalReferenceCountType [protected, inherited]

Define the type of the reference count according to the target. This allows the use of atomic operations

Definition at line 139 of file itkLightObject.h.

template<class TImageType>

typedef Vector<PixelRealType,itkGetStaticConstMacro(ImageDimension)> itk::FiniteDifferenceFunction< TImageType >::NeighborhoodScalesType

The type of data structure that holds the scales with which the neighborhood is weighted to properly account for spacing and neighborhood radius.

Reimplemented in itk::CurvatureFlowFunction< TImage >, itk::LevelSetFunctionWithRefitTerm< TImageType, TSparseImageType >, itk::NormalVectorDiffusionFunction< TSparseImageType >, itk::LevelSetFunction< TImageType >, itk::RegionBasedLevelSetFunction< TInput, TFeature, TSharedData >, and itk::RegionBasedLevelSetFunction< TInputImage, TFeatureImage, TSharedData >.

Definition at line 103 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef ConstNeighborhoodIterator<TImageType, DefaultBoundaryConditionType> itk::FiniteDifferenceFunction< TImageType >::NeighborhoodType

The type of data structure that is passed to this function object to evaluate at a pixel that does not lie on a data set boundary.

Definition at line 99 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef double itk::FiniteDifferenceFunction< TImageType >::PixelRealType

Reimplemented in itk::CurvatureFlowFunction< TImage >, itk::GradientNDAnisotropicDiffusionFunction< TImage >, itk::ScalarAnisotropicDiffusionFunction< TImage >, itk::LevelSetFunction< TImageType >, and itk::SegmentationLevelSetFunction< TImageType, TFeatureImageType >.

Definition at line 81 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef ImageType::PixelType itk::FiniteDifferenceFunction< TImageType >::PixelType

Definition at line 80 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef SmartPointer<Self> itk::FiniteDifferenceFunction< TImageType >::Pointer

Reimplemented from itk::LightObject.

Definition at line 72 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef ConstNeighborhoodIterator<TImageType>::RadiusType itk::FiniteDifferenceFunction< TImageType >::RadiusType

Neighborhood radius type

Definition at line 95 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef FiniteDifferenceFunction itk::FiniteDifferenceFunction< TImageType >::Self

Standard class typedefs.

Reimplemented from itk::LightObject.

Definition at line 70 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef LightObject itk::FiniteDifferenceFunction< TImageType >::Superclass

Definition at line 71 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

typedef double itk::FiniteDifferenceFunction< TImageType >::TimeStepType

Define the TimeStepType to always be double.

Definition at line 87 of file itkFiniteDifferenceFunction.h.

Constructor & Destructor Documentation

template<class TImageType>

itk::FiniteDifferenceFunction< TImageType >::FiniteDifferenceFunction ( ) [inline, protected]

Definition at line 191 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

itk::FiniteDifferenceFunction< TImageType >::~FiniteDifferenceFunction ( ) [inline, protected]

Definition at line 200 of file itkFiniteDifferenceFunction.h.

Member Function Documentation

static void itk::LightObject::BreakOnError ( ) [static, inherited]

This method is called when itkExceptionMacro executes. It allows the debugger to break on error.

template<class TImageType>

virtual TimeStepType itk::FiniteDifferenceFunction< TImageType >::ComputeGlobalTimeStep ( void * GlobalData ) const [pure virtual]

Computes the time step for an update given a global data structure. The data used in the computation may take different forms depending on the nature of the equations. This global data cannot be kept in the instance of the equation object itself since the equation object must remain stateless for thread safety. The global data is therefore managed for each thread by the finite difference solver filters.

template<class TImageType>

const NeighborhoodScalesType itk::FiniteDifferenceFunction< TImageType >::ComputeNeighborhoodScales ( ) const

Compute the scales that weight the neighborhood during difference operations to properly account for spacing and neighborhood radius

template<class TImageType>

virtual PixelType itk::FiniteDifferenceFunction< TImageType >::ComputeUpdate	(	const NeighborhoodType &	neighborhood,
		void *	globalData,
		const FloatOffsetType &	offset = `FloatOffsetType(0.0)`
	)			`[pure virtual]`

This method is called by a finite difference solver image filter at each pixel that does not lie on a data set boundary. The width of the data set boundary is defined by the width of the neighborhood being evaluated.

The neighborhood argument is the neighborhood data. The globalData argument is a pointer to a data structure that holds values that need to be persistent across calls to this function, but cannot be stored in the function object itself for thread-safety reasons. Examples are values needed to compute the time-step for an iteration of the solver.

See also:: InitializeIteration; ComputeGlobalTimeStep

virtual Pointer itk::LightObject::CreateAnother ( ) const [virtual, inherited]

Create an object from an instance, potentially deferring to a factory. This method allows you to create an instance of an object that is exactly the same type as the referring object. This is useful in cases where an object has been cast back to a base class.

virtual void itk::LightObject::Delete ( ) [virtual, inherited]

Delete an itk object. This method should always be used to delete an object when the new operator was used to create it. Using the C delete method will not work with reference counting.

template<class TImageType>

virtual void* itk::FiniteDifferenceFunction< TImageType >::GetGlobalDataPointer ( ) const [pure virtual]

Returns a pointer to a global data structure that is passed to this object from the solver at each calculation. The idea is that the solver holds the state of any global values needed to calculate the time step, while the equation object performs the actual calculations.

The global data should also be initialized in this method.

template<class TImageType>

virtual const char* itk::FiniteDifferenceFunction< TImageType >::GetNameOfClass ( ) const [virtual]

Run-time type information (and related methods)

Reimplemented from itk::LightObject.

template<class TImageType>

const RadiusType& itk::FiniteDifferenceFunction< TImageType >::GetRadius ( void ) const [inline]

Returns the radius of the neighborhood this FiniteDifferenceFunction needs to perform its calculations.

Definition at line 146 of file itkFiniteDifferenceFunction.h.

virtual int itk::LightObject::GetReferenceCount ( ) const [inline, virtual, inherited]

Gets the reference count on this object.

Definition at line 106 of file itkLightObject.h.

template<class TImageType>

virtual void itk::FiniteDifferenceFunction< TImageType >::InitializeIteration ( ) [inline, virtual]

This method allows the function to set its state before each iteration of the finite difference solver (image filter) that uses it. This is a thread-safe time to manipulate the object's state.

An example of how this can be used: the Anisotropic diffusion class of FiniteDifferenceFunctions use this method to pre-calculate an average gradient magnitude across the entire image region. This value is set in the function object and used by the ComputeUpdate methods that are called at each pixel as a constant.

Definition at line 118 of file itkFiniteDifferenceFunction.h.

static Pointer itk::LightObject::New ( ) [static, inherited]

Method for creation through the object factory.

Referenced by itk::RegionBasedLevelSetFunctionSharedData< TInputImage, TFeatureImage, TSingleData >::SetFunctionCount().

void itk::LightObject::Print	(	std::ostream &	os,
		Indent	indent = `0`
	)			const `[inherited]`

Cause the object to print itself out.

Referenced by itk::WeakPointer< ProcessObject >::Print().

virtual void itk::LightObject::PrintHeader	(	std::ostream &	os,
		Indent	indent
	)			const `[protected, virtual, inherited]`

Methods invoked by Print() to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

template<class TImageType>

void itk::FiniteDifferenceFunction< TImageType >::PrintSelf	(	std::ostream &	os,
		Indent	indent
	)			const `[protected, virtual]`

Methods invoked by Print() to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

Reimplemented from itk::LightObject.

virtual void itk::LightObject::PrintTrailer	(	std::ostream &	os,
		Indent	indent
	)			const `[protected, virtual, inherited]`

Methods invoked by Print() to print information about the object including superclasses. Typically not called by the user (use Print() instead) but used in the hierarchical print process to combine the output of several classes.

virtual void itk::LightObject::Register ( ) const [virtual, inherited]

Increase the reference count (mark as used by another object).

Reimplemented in itk::Object.

template<class TImageType>

virtual void itk::FiniteDifferenceFunction< TImageType >::ReleaseGlobalDataPointer ( void * GlobalData ) const [pure virtual]

When the finite difference solver filter has finished using a global data pointer, it passes it to this method, which frees the memory.

The solver cannot free the memory because it does not know the type to which the pointer points.

template<class TImageType>

void itk::FiniteDifferenceFunction< TImageType >::SetRadius ( const RadiusType & r ) [inline]

Sets the radius of the neighborhood this FiniteDifferenceFunction needs to perform its calculations.

Definition at line 141 of file itkFiniteDifferenceFunction.h.

virtual void itk::LightObject::SetReferenceCount ( int ) [virtual, inherited]

Sets the reference count on this object. This is a dangerous method, use it with care.

Reimplemented in itk::Object.

template<class TImageType>

void itk::FiniteDifferenceFunction< TImageType >::SetScaleCoefficients ( PixelRealType vals[ImageDimension] ) [inline]

Set the ScaleCoefficients for the difference operators. The defaults a 1.0. These can be set to take the image spacing into account.

Definition at line 152 of file itkFiniteDifferenceFunction.h.

virtual void itk::LightObject::UnRegister ( ) const [virtual, inherited]

Decrease the reference count (release by another object).

Reimplemented in itk::Object.

Member Data Documentation

template<class TImageType>

const unsigned int itk::FiniteDifferenceFunction< TImageType >::ImageDimension = ImageType::ImageDimension [static]

Save image dimension.

Definition at line 84 of file itkFiniteDifferenceFunction.h.

template<class TImageType>

RadiusType itk::FiniteDifferenceFunction< TImageType >::m_Radius [protected]

Definition at line 203 of file itkFiniteDifferenceFunction.h.

InternalReferenceCountType itk::LightObject::m_ReferenceCount [mutable, protected, inherited]

Number of uses of this object by other objects.

Definition at line 144 of file itkLightObject.h.

SimpleFastMutexLock itk::LightObject::m_ReferenceCountLock [mutable, protected, inherited]

Mutex lock to protect modification to the reference count

Definition at line 147 of file itkLightObject.h.

template<class TImageType>

PixelRealType itk::FiniteDifferenceFunction< TImageType >::m_ScaleCoefficients[ImageDimension] [protected]

Definition at line 204 of file itkFiniteDifferenceFunction.h.

The documentation for this class was generated from the following file:

itkFiniteDifferenceFunction.h

itk::FiniteDifferenceFunction< TImageType > Class Template Reference [Functions]

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Types

Protected Member Functions

Protected Attributes

Detailed Description

template<class TImageType> class itk::FiniteDifferenceFunction< TImageType >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

itk::FiniteDifferenceFunction< TImageType > Class Template Reference
[Functions]

template<class TImageType>
class itk::FiniteDifferenceFunction< TImageType >