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itk::GradientNDAnisotropicDiffusionFunction< TImage > Class Template Reference
[Finite Difference FunctionsImage Enhancement Filters]

#include <itkGradientNDAnisotropicDiffusionFunction.h>

Inheritance diagram for itk::GradientNDAnisotropicDiffusionFunction< TImage >:

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List of all members.

Detailed Description

template<class TImage>
class itk::GradientNDAnisotropicDiffusionFunction< TImage >

This class implements an N-dimensional version of the classic Perona-Malik anisotropic diffusion equation for scalar-valued images. See itkAnisotropicDiffusionFunction for an overview of the anisotropic diffusion framework and equation.

The conductance term for this implementation is chosen as a function of the gradient magnitude of the image at each point, reducing the strength of diffusion at edge pixels.

\[C(\mathbf{x}) = e^{-(\frac{\parallel \nabla U(\mathbf{x}) \parallel}{K})^2}\]

.

The numerical implementation of this equation is similar to that described in the Perona-Malik paper below, but uses a more robust technique for gradient magnitude estimation and has been generalized to N-dimensions.
References
Pietro Perona and Jalhandra Malik, ``Scale-space and edge detection using anisotropic diffusion,'' IEEE Transactions on Pattern Analysis Machine Intelligence, vol. 12, pp. 629-639, 1990.
See also:
AnisotropicDiffusionFunction

VectorAnisotropicDiffusionFunction

VectorGradientAnisotropicDiffusionFunction

CurvatureNDAnisotropicDiffusionFunction

Definition at line 59 of file itkGradientNDAnisotropicDiffusionFunction.h.

Public Types

typedef SmartPointer< const
Self
ConstPointer
typedef ZeroFluxNeumannBoundaryCondition<
ImageType
DefaultBoundaryConditionType
typedef Superclass::FloatOffsetType FloatOffsetType
typedef Superclass::ImageType ImageType
typedef Vector< PixelRealType,
itkGetStaticConstMacro(ImageDimension)> 
NeighborhoodScalesType
typedef Superclass::NeighborhoodType NeighborhoodType
typedef Superclass::PixelRealType PixelrealType
typedef Superclass::PixelRealType PixelRealType
typedef Superclass::PixelType PixelType
typedef SmartPointer< SelfPointer
typedef Superclass::RadiusType RadiusType
typedef GradientNDAnisotropicDiffusionFunction Self
typedef ScalarAnisotropicDiffusionFunction<
TImage > 
Superclass
typedef Superclass::TimeStepType TimeStepType

Public Member Functions

virtual void CalculateAverageGradientMagnitudeSquared (ImageType *)=0
virtual void CalculateAverageGradientMagnitudeSquared (TImage *)
virtual TimeStepType ComputeGlobalTimeStep (void *) const
const NeighborhoodScalesType ComputeNeighborhoodScales () const
virtual PixelType ComputeUpdate (const NeighborhoodType &neighborhood, void *globalData, const FloatOffsetType &offset=FloatOffsetType(0.0))=0
virtual PixelType ComputeUpdate (const NeighborhoodType &neighborhood, void *globalData, const FloatOffsetType &offset=FloatOffsetType(0.0))
virtual Pointer CreateAnother () const
virtual void Delete ()
virtual void * GetGlobalDataPointer () const
virtual const char * GetNameOfClass () const
const RadiusTypeGetRadius () const
virtual int GetReferenceCount () const
virtual void InitializeIteration ()
 itkStaticConstMacro (ImageDimension, unsigned int, ImageType::ImageDimension)
 itkStaticConstMacro (ImageDimension, unsigned int, Superclass::ImageDimension)
void Print (std::ostream &os, Indent indent=0) const
virtual void Register () const
virtual void ReleaseGlobalDataPointer (void *) const
void SetRadius (const RadiusType &r)
virtual void SetReferenceCount (int)
void SetScaleCoefficients (PixelRealType vals[ImageDimension])
virtual void UnRegister () const
const double & GetAverageGradientMagnitudeSquared () const
void SetAverageGradientMagnitudeSquared (const double &c)
const double & GetConductanceParameter () const
void SetConductanceParameter (const double &c)
const TimeStepTypeGetTimeStep () const
void SetTimeStep (const TimeStepType &t)

Static Public Member Functions

static void BreakOnError ()
static Pointer New ()

Protected Member Functions

 GradientNDAnisotropicDiffusionFunction ()
void PrintSelf (std::ostream &os, Indent indent) const
 ~GradientNDAnisotropicDiffusionFunction ()
virtual void PrintHeader (std::ostream &os, Indent indent) const
virtual void PrintTrailer (std::ostream &os, Indent indent) const

Protected Attributes

DerivativeOperator< PixelType,
itkGetStaticConstMacro(ImageDimension)> 
dx_op
unsigned long m_Center
NeighborhoodInnerProduct<
ImageType
m_InnerProduct
PixelType m_K
RadiusType m_Radius
volatile int m_ReferenceCount
SimpleFastMutexLock m_ReferenceCountLock
PixelRealType m_ScaleCoefficients [ImageDimension]
unsigned long m_Stride [ImageDimension]
std::slice x_slice [ImageDimension]
std::slice xa_slice [ImageDimension][ImageDimension]
std::slice xd_slice [ImageDimension][ImageDimension]

Static Protected Attributes

static double m_MIN_NORM


Member Typedef Documentation

template<class TImage>
typedef SmartPointer<const Self> itk::GradientNDAnisotropicDiffusionFunction< TImage >::ConstPointer

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 67 of file itkGradientNDAnisotropicDiffusionFunction.h.

typedef ZeroFluxNeumannBoundaryCondition<ImageType> itk::FiniteDifferenceFunction< TImage >::DefaultBoundaryConditionType [inherited]

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

Definition at line 93 of file itkFiniteDifferenceFunction.h.

template<class TImage>
typedef Superclass::FloatOffsetType itk::GradientNDAnisotropicDiffusionFunction< TImage >::FloatOffsetType

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

Reimplemented from itk::AnisotropicDiffusionFunction< TImage >.

Definition at line 83 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef Superclass::ImageType itk::GradientNDAnisotropicDiffusionFunction< TImage >::ImageType

Inherit some parameters from the superclass type.

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 74 of file itkGradientNDAnisotropicDiffusionFunction.h.

typedef Vector<PixelRealType,itkGetStaticConstMacro(ImageDimension)> itk::FiniteDifferenceFunction< TImage >::NeighborhoodScalesType [inherited]

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 >.

Definition at line 104 of file itkFiniteDifferenceFunction.h.

template<class TImage>
typedef Superclass::NeighborhoodType itk::GradientNDAnisotropicDiffusionFunction< TImage >::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.

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 82 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef Superclass::PixelRealType itk::AnisotropicDiffusionFunction< TImage >::PixelrealType [inherited]

Definition at line 152 of file itkAnisotropicDiffusionFunction.h.

template<class TImage>
typedef Superclass::PixelRealType itk::GradientNDAnisotropicDiffusionFunction< TImage >::PixelRealType

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 79 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef Superclass::PixelType itk::GradientNDAnisotropicDiffusionFunction< TImage >::PixelType

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 78 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef SmartPointer<Self> itk::GradientNDAnisotropicDiffusionFunction< TImage >::Pointer

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 66 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef Superclass::RadiusType itk::GradientNDAnisotropicDiffusionFunction< TImage >::RadiusType

Neighborhood radius type

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 81 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef GradientNDAnisotropicDiffusionFunction itk::GradientNDAnisotropicDiffusionFunction< TImage >::Self

Standard class typedefs.

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 64 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef ScalarAnisotropicDiffusionFunction<TImage> itk::GradientNDAnisotropicDiffusionFunction< TImage >::Superclass

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 65 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
typedef Superclass::TimeStepType itk::GradientNDAnisotropicDiffusionFunction< TImage >::TimeStepType

Define the TimeStepType to always be double.

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 80 of file itkGradientNDAnisotropicDiffusionFunction.h.


Constructor & Destructor Documentation

template<class TImage>
itk::GradientNDAnisotropicDiffusionFunction< TImage >::GradientNDAnisotropicDiffusionFunction (  )  [protected]

template<class TImage>
itk::GradientNDAnisotropicDiffusionFunction< TImage >::~GradientNDAnisotropicDiffusionFunction (  )  [inline, protected]

Definition at line 103 of file itkGradientNDAnisotropicDiffusionFunction.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 TImage>
virtual void itk::AnisotropicDiffusionFunction< TImage >::CalculateAverageGradientMagnitudeSquared ( ImageType  )  [pure virtual, inherited]

This method is called before each iteration. It calculates a scalar value that is the average of the gradient magnitude squared at each pixel in the output image (intermediate solution). The average gradient magnitude value is typically used in the anisotropic diffusion equations to calibrate the conductance term.

template<class TImage>
virtual void itk::ScalarAnisotropicDiffusionFunction< TImage >::CalculateAverageGradientMagnitudeSquared ( TImage *   )  [virtual, inherited]

template<class TImage>
virtual TimeStepType itk::AnisotropicDiffusionFunction< TImage >::ComputeGlobalTimeStep ( void *   )  const [inline, virtual, inherited]

Returns the time step supplied by the user. We don't need to use the global data supplied since we are returning a fixed value.

Implements itk::FiniteDifferenceFunction< TImage >.

Definition at line 193 of file itkAnisotropicDiffusionFunction.h.

const NeighborhoodScalesType itk::FiniteDifferenceFunction< TImage >::ComputeNeighborhoodScales (  )  const [inherited]

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

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

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

template<class TImage>
virtual PixelType itk::GradientNDAnisotropicDiffusionFunction< TImage >::ComputeUpdate ( const NeighborhoodType neighborhood,
void *  globalData,
const FloatOffsetType offset = FloatOffsetType(0.0) 
) [virtual]

Compute the equation value.

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.

Reimplemented in itk::Object.

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 TImage>
const double& itk::AnisotropicDiffusionFunction< TImage >::GetAverageGradientMagnitudeSquared (  )  const [inline, inherited]

Set/Get the average gradient magnitude squared.

Definition at line 185 of file itkAnisotropicDiffusionFunction.h.

template<class TImage>
const double& itk::AnisotropicDiffusionFunction< TImage >::GetConductanceParameter (  )  const [inline, inherited]

Definition at line 180 of file itkAnisotropicDiffusionFunction.h.

template<class TImage>
virtual void* itk::AnisotropicDiffusionFunction< TImage >::GetGlobalDataPointer (  )  const [inline, virtual, inherited]

The anisotropic diffusion classes don't use this particular parameter so it's safe to return a null value.

Implements itk::FiniteDifferenceFunction< TImage >.

Definition at line 198 of file itkAnisotropicDiffusionFunction.h.

template<class TImage>
virtual const char* itk::GradientNDAnisotropicDiffusionFunction< TImage >::GetNameOfClass (  )  const [virtual]

Run-time type information (and related methods)

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

const RadiusType& itk::FiniteDifferenceFunction< TImage >::GetRadius ( void   )  const [inline, inherited]

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

Definition at line 147 of file itkFiniteDifferenceFunction.h.

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

Gets the reference count on this object.

Definition at line 98 of file itkLightObject.h.

template<class TImage>
const TimeStepType& itk::AnisotropicDiffusionFunction< TImage >::GetTimeStep (  )  const [inline, inherited]

Definition at line 173 of file itkAnisotropicDiffusionFunction.h.

template<class TImage>
virtual void itk::GradientNDAnisotropicDiffusionFunction< TImage >::InitializeIteration (  )  [inline, virtual]

This method is called prior to each iteration of the solver.

Reimplemented from itk::FiniteDifferenceFunction< TImage >.

Definition at line 95 of file itkGradientNDAnisotropicDiffusionFunction.h.

itk::FiniteDifferenceFunction< TImage >::itkStaticConstMacro ( ImageDimension  ,
unsigned  int,
ImageType::ImageDimension   
) [inherited]

Save image dimension.

template<class TImage>
itk::GradientNDAnisotropicDiffusionFunction< TImage >::itkStaticConstMacro ( ImageDimension  ,
unsigned  int,
Superclass::ImageDimension   
)

Inherit some parameters from the superclass type.

Reimplemented from itk::ScalarAnisotropicDiffusionFunction< TImage >.

template<class TImage>
static Pointer itk::GradientNDAnisotropicDiffusionFunction< TImage >::New (  )  [static]

Method for creation through the object factory.

Reimplemented from itk::LightObject.

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

Cause the object to print itself out.

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

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

template<class TImage>
void itk::GradientNDAnisotropicDiffusionFunction< TImage >::PrintSelf ( std::ostream &  os,
Indent  indent 
) const [inline, 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::ScalarAnisotropicDiffusionFunction< TImage >.

Definition at line 105 of file itkGradientNDAnisotropicDiffusionFunction.h.

References HardConnectedComponentImageFilter::PrintSelf().

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

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

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

Reimplemented in itk::Object.

template<class TImage>
virtual void itk::AnisotropicDiffusionFunction< TImage >::ReleaseGlobalDataPointer ( void *   )  const [inline, virtual, inherited]

Does nothing. No global data is used in this class of equations.

Implements itk::FiniteDifferenceFunction< TImage >.

Definition at line 202 of file itkAnisotropicDiffusionFunction.h.

template<class TImage>
void itk::AnisotropicDiffusionFunction< TImage >::SetAverageGradientMagnitudeSquared ( const double &  c  )  [inline, inherited]

Set/Get the average gradient magnitude squared.

Definition at line 187 of file itkAnisotropicDiffusionFunction.h.

template<class TImage>
void itk::AnisotropicDiffusionFunction< TImage >::SetConductanceParameter ( const double &  c  )  [inline, inherited]

Set/Get the conductance parameter. The conductance parameter

Definition at line 178 of file itkAnisotropicDiffusionFunction.h.

void itk::FiniteDifferenceFunction< TImage >::SetRadius ( const RadiusType r  )  [inline, inherited]

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

Definition at line 142 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.

void itk::FiniteDifferenceFunction< TImage >::SetScaleCoefficients ( PixelRealType  vals[ImageDimension]  )  [inline, inherited]

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 153 of file itkFiniteDifferenceFunction.h.

template<class TImage>
void itk::AnisotropicDiffusionFunction< TImage >::SetTimeStep ( const TimeStepType t  )  [inline, inherited]

Set/Get the time step. For this class of anisotropic diffusion filters, the time-step is supplied by the user and remains fixed for all updates.

Definition at line 171 of file itkAnisotropicDiffusionFunction.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 TImage>
DerivativeOperator<PixelType, itkGetStaticConstMacro(ImageDimension)> itk::GradientNDAnisotropicDiffusionFunction< TImage >::dx_op [protected]

Derivative operator.

Definition at line 117 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
unsigned long itk::GradientNDAnisotropicDiffusionFunction< TImage >::m_Center [protected]

Definition at line 122 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
NeighborhoodInnerProduct<ImageType> itk::GradientNDAnisotropicDiffusionFunction< TImage >::m_InnerProduct [protected]

Inner product function.

Definition at line 109 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
PixelType itk::GradientNDAnisotropicDiffusionFunction< TImage >::m_K [protected]

Modified global average gradient magnitude term.

Definition at line 120 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
double itk::GradientNDAnisotropicDiffusionFunction< TImage >::m_MIN_NORM [static, protected]

Definition at line 125 of file itkGradientNDAnisotropicDiffusionFunction.h.

RadiusType itk::FiniteDifferenceFunction< TImage >::m_Radius [protected, inherited]

Definition at line 204 of file itkFiniteDifferenceFunction.h.

volatile int itk::LightObject::m_ReferenceCount [mutable, protected, inherited]

Number of uses of this object by other objects.

Definition at line 119 of file itkLightObject.h.

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

Mutex lock to protect modification to the reference count

Definition at line 122 of file itkLightObject.h.

PixelRealType itk::FiniteDifferenceFunction< TImage >::m_ScaleCoefficients[ImageDimension] [protected, inherited]

Definition at line 205 of file itkFiniteDifferenceFunction.h.

template<class TImage>
unsigned long itk::GradientNDAnisotropicDiffusionFunction< TImage >::m_Stride[ImageDimension] [protected]

Definition at line 123 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
std::slice itk::GradientNDAnisotropicDiffusionFunction< TImage >::x_slice[ImageDimension] [protected]

Slices for the ND neighborhood.

Definition at line 112 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
std::slice itk::GradientNDAnisotropicDiffusionFunction< TImage >::xa_slice[ImageDimension][ImageDimension] [protected]

Definition at line 113 of file itkGradientNDAnisotropicDiffusionFunction.h.

template<class TImage>
std::slice itk::GradientNDAnisotropicDiffusionFunction< TImage >::xd_slice[ImageDimension][ImageDimension] [protected]

Definition at line 114 of file itkGradientNDAnisotropicDiffusionFunction.h.


The documentation for this class was generated from the following file:
Generated at Mon Apr 14 18:10:34 2008 for ITK by doxygen 1.5.1 written by Dimitri van Heesch, © 1997-2000