Base class for computing IIR convolution with an approximation of a Gaussian kernel. More...

#include <sitkRecursiveGaussianImageFilter.h>

Inheritance diagram for itk::simple::RecursiveGaussianImageFilter:

Collaboration diagram for itk::simple::RecursiveGaussianImageFilter:

Detailed Description

Base class for computing IIR convolution with an approximation of a Gaussian kernel.

\[ \frac{ 1 }{ \sigma \sqrt{ 2 \pi } } \exp{ \left( - \frac{x^2}{ 2 \sigma^2 } \right) } \]

RecursiveGaussianImageFilter is the base class for recursive filters that approximate convolution with the Gaussian kernel. This class implements the recursive filtering method proposed by R.Deriche in IEEE-PAMI Vol.12, No.1, January 1990, pp 78-87, "Fast Algorithms for Low-Level Vision"

Details of the implementation are described in the technical report: R. Deriche, "Recursively Implementing The Gaussian and Its Derivatives", INRIA, 1993, ftp://ftp.inria.fr/INRIA/tech-reports/RR/RR-1893.ps.gz

Further improvements of the algorithm are described in: G. Farnebäck & C.-F. Westin, "Improving Deriche-style Recursive Gaussian Filters". J Math Imaging Vis 26, 293–299 (2006). https://doi.org/10.1007/s10851-006-8464-z

As compared to itk::DiscreteGaussianImageFilter , this filter tends to be faster for large kernels, and it can take the derivative of the blurred image in one step. Also, note that we have itk::RecursiveGaussianImageFilter::SetSigma() , but itk::DiscreteGaussianImageFilter::SetVariance() .

See also: DiscreteGaussianImageFilter; itk::simple::RecursiveGaussian for the procedural interface; itk::RecursiveGaussianImageFilter for the Doxygen on the original ITK class.

Definition at line 52 of file sitkRecursiveGaussianImageFilter.h.

Public Types
enum	OrderType { ZeroOrder, FirstOrder, SecondOrder }

using	PixelIDTypeList = typelist2::append< BasicPixelIDTypeList, VectorPixelIDTypeList >::type

using	Self = RecursiveGaussianImageFilter

Public Types inherited from itk::simple::ImageFilter
using	Self = ImageFilter

Public Types inherited from itk::simple::ProcessObject
using	Self = ProcessObject

Public Member Functions
Image	Execute (const Image &image1)

Image	Execute (Image &&image1)

unsigned int	GetDirection () const

std::string	GetName () const

bool	GetNormalizeAcrossScale () const

OrderType	GetOrder () const

double	GetSigma () const

Self &	NormalizeAcrossScaleOff ()

Self &	NormalizeAcrossScaleOn ()

	RecursiveGaussianImageFilter ()

Self &	SetDirection (unsigned int Direction)

Self &	SetNormalizeAcrossScale (bool NormalizeAcrossScale)

Self &	SetOrder (OrderType Order)

Self &	SetSigma (double Sigma)

std::string	ToString () const

virtual	~RecursiveGaussianImageFilter ()

Public Member Functions inherited from itk::simple::ImageFilter
	ImageFilter ()

virtual	~ImageFilter ()=0

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

virtual int	AddCommand (itk::simple::EventEnum event, const std::function< void()> &func)
	Directly add a callback to observe an event. More...

virtual int	AddCommand (itk::simple::EventEnum event, itk::simple::Command &cmd)
	Add a Command Object to observer the event. More...

virtual float	GetProgress () const
	An Active Measurement of the progress of execution. More...

virtual bool	HasCommand (itk::simple::EventEnum event) const
	Query of this object has any registered commands for event. More...

	ProcessObject ()

virtual void	RemoveAllCommands ()
	Remove all registered commands. More...

virtual	~ProcessObject ()

virtual void	DebugOn ()

virtual void	DebugOff ()

virtual bool	GetDebug () const

virtual void	SetDebug (bool debugFlag)

virtual void	SetNumberOfThreads (unsigned int n)

virtual unsigned int	GetNumberOfThreads () const

virtual void	SetNumberOfWorkUnits (unsigned int n)

virtual unsigned int	GetNumberOfWorkUnits () const

Private Types
using	MemberFunctionType = Image(Self::*)(const Image &image1)

Private Member Functions
template<class TImageType >
Image	ExecuteInternal (const Image &image1)

Private Attributes
unsigned int	m_Direction {0u}

bool	m_InPlace {false}

std::unique_ptr< detail::MemberFunctionFactory< MemberFunctionType > >	m_MemberFactory

bool	m_NormalizeAcrossScale {false}

OrderType	m_Order {itk::simple::RecursiveGaussianImageFilter::ZeroOrder}

double	m_Sigma {1.0}

Friends
struct	detail::MemberFunctionAddressor< MemberFunctionType >

Additional Inherited Members
Static Public Member Functions inherited from itk::simple::ProcessObject
static bool	GetGlobalDefaultDebug ()

static void	GlobalDefaultDebugOff ()

static void	GlobalDefaultDebugOn ()

static void	SetGlobalDefaultDebug (bool debugFlag)

static void	GlobalWarningDisplayOn ()

static void	GlobalWarningDisplayOff ()

static void	SetGlobalWarningDisplay (bool flag)

static bool	GetGlobalWarningDisplay ()

static double	GetGlobalDefaultCoordinateTolerance ()
	Access the global tolerance to determine congruent spaces. More...

static void	SetGlobalDefaultCoordinateTolerance (double)
	Access the global tolerance to determine congruent spaces. More...

static double	GetGlobalDefaultDirectionTolerance ()
	Access the global tolerance to determine congruent spaces. More...

static void	SetGlobalDefaultDirectionTolerance (double)
	Access the global tolerance to determine congruent spaces. More...

static bool	SetGlobalDefaultThreader (const std::string &threader)
	Set/Get the default threader used for process objects. More...

static std::string	GetGlobalDefaultThreader ()
	Set/Get the default threader used for process objects. More...

static void	SetGlobalDefaultNumberOfThreads (unsigned int n)

static unsigned int	GetGlobalDefaultNumberOfThreads ()
	Set/Get the default threader used for process objects. More...

Protected Member Functions inherited from itk::simple::ImageFilter
void	CheckImageMatchingDimension (const Image &image1, const Image &image2, const std::string &image2Name)

void	CheckImageMatchingPixelType (const Image &image1, const Image &image2, const std::string &image2Name)

void	CheckImageMatchingSize (const Image &image1, const Image &image2, const std::string &image2Name)

Protected Member Functions inherited from itk::simple::ProcessObject
virtual unsigned long	AddITKObserver (const itk::EventObject &, itk::Command *)

virtual itk::ProcessObject *	GetActiveProcess ()

virtual void	OnActiveProcessDelete ()

virtual void	onCommandDelete (const itk::simple::Command *cmd) noexcept

virtual void	PreUpdate (itk::ProcessObject *p)

virtual void	RemoveITKObserver (EventCommand &e)

Protected Member Functions inherited from itk::simple::NonCopyable
	NonCopyable ()=default

	NonCopyable (const NonCopyable &)=delete

NonCopyable &	operator= (const NonCopyable &)=delete

Static Protected Member Functions inherited from itk::simple::ImageFilter
template<class TImageType >
static void	FixNonZeroIndex (TImageType *img)

Static Protected Member Functions inherited from itk::simple::ProcessObject
template<class TImageType >
static TImageType::ConstPointer	CastImageToITK (const Image &img)

template<class TPixelType , unsigned int VImageDimension, unsigned int VLength, template< typename, unsigned int > class TVector>
static Image	CastITKToImage (itk::Image< TVector< TPixelType, VLength >, VImageDimension > *img)

template<unsigned int VImageDimension, unsigned int VLength, template< unsigned int > class TVector>
static Image	CastITKToImage (itk::Image< TVector< VLength >, VImageDimension > *img)

template<class TImageType >
static Image	CastITKToImage (TImageType *img)

static const itk::EventObject &	GetITKEventObject (EventEnum e)

template<typename T >
static std::ostream &	ToStringHelper (std::ostream &os, const T &v)

static std::ostream &	ToStringHelper (std::ostream &os, const char &v)

static std::ostream &	ToStringHelper (std::ostream &os, const signed char &v)

static std::ostream &	ToStringHelper (std::ostream &os, const unsigned char &v)

Member Typedef Documentation

◆ MemberFunctionType

using itk::simple::RecursiveGaussianImageFilter::MemberFunctionType = Image (Self::*)( const Image& image1 )

private

Setup for member function dispatching

Definition at line 159 of file sitkRecursiveGaussianImageFilter.h.

◆ PixelIDTypeList

using itk::simple::RecursiveGaussianImageFilter::PixelIDTypeList = typelist2::append<BasicPixelIDTypeList, VectorPixelIDTypeList>::type

Define the pixels types supported by this filter

Definition at line 64 of file sitkRecursiveGaussianImageFilter.h.

◆ Self

using itk::simple::RecursiveGaussianImageFilter::Self = RecursiveGaussianImageFilter

Definition at line 54 of file sitkRecursiveGaussianImageFilter.h.

Member Enumeration Documentation

◆ OrderType

enum itk::simple::RecursiveGaussianImageFilter::OrderType

Enumerator
ZeroOrder
FirstOrder
SecondOrder

Definition at line 106 of file sitkRecursiveGaussianImageFilter.h.

Constructor & Destructor Documentation

◆ ~RecursiveGaussianImageFilter()

virtual itk::simple::RecursiveGaussianImageFilter::~RecursiveGaussianImageFilter ( )

virtual

Destructor

◆ RecursiveGaussianImageFilter()

itk::simple::RecursiveGaussianImageFilter::RecursiveGaussianImageFilter ( )

Default Constructor that takes no arguments and initializes default parameters

Member Function Documentation

◆ Execute() [1/2]

Image itk::simple::RecursiveGaussianImageFilter::Execute ( const Image & image1 )

◆ Execute() [2/2]

Image itk::simple::RecursiveGaussianImageFilter::Execute ( Image && image1 )

Execute the filter on the input image

◆ ExecuteInternal()

template<class TImageType >

Image itk::simple::RecursiveGaussianImageFilter::ExecuteInternal ( const Image & image1 )

private

◆ GetDirection()

unsigned int itk::simple::RecursiveGaussianImageFilter::GetDirection ( ) const

inline

Definition at line 140 of file sitkRecursiveGaussianImageFilter.h.

◆ GetName()

std::string itk::simple::RecursiveGaussianImageFilter::GetName ( ) const

inlinevirtual

Name of this class

Implements itk::simple::ProcessObject.

Definition at line 143 of file sitkRecursiveGaussianImageFilter.h.

◆ GetNormalizeAcrossScale()

bool itk::simple::RecursiveGaussianImageFilter::GetNormalizeAcrossScale ( ) const

inline

Definition at line 104 of file sitkRecursiveGaussianImageFilter.h.

◆ GetOrder()

OrderType itk::simple::RecursiveGaussianImageFilter::GetOrder ( ) const

inline

     Set/Get the Order of the Gaussian to convolve with.

ZeroOrder is equivalent to convolving with a Gaussian. This is the default.

FirstOrder is equivalent to convolving with the first derivative of a Gaussian.

SecondOrder is equivalent to convolving with the second derivative of a Gaussian.

Definition at line 132 of file sitkRecursiveGaussianImageFilter.h.

◆ GetSigma()

double itk::simple::RecursiveGaussianImageFilter::GetSigma ( ) const

inline

Set/Get the Sigma, measured in world coordinates, of the Gaussian kernel. The default is 1.0. An exception will be generated if the Sigma value is less than or equal to zero.

Definition at line 75 of file sitkRecursiveGaussianImageFilter.h.

◆ NormalizeAcrossScaleOff()

Self& itk::simple::RecursiveGaussianImageFilter::NormalizeAcrossScaleOff ( )

inline

Definition at line 100 of file sitkRecursiveGaussianImageFilter.h.

◆ NormalizeAcrossScaleOn()

Self& itk::simple::RecursiveGaussianImageFilter::NormalizeAcrossScaleOn ( )

inline

Set the value of NormalizeAcrossScale to true or false respectfully.

Definition at line 99 of file sitkRecursiveGaussianImageFilter.h.

◆ SetDirection()

Self& itk::simple::RecursiveGaussianImageFilter::SetDirection ( unsigned int Direction )

inline

Definition at line 136 of file sitkRecursiveGaussianImageFilter.h.

◆ SetNormalizeAcrossScale()

Self& itk::simple::RecursiveGaussianImageFilter::SetNormalizeAcrossScale ( bool NormalizeAcrossScale )

inline

     Set/Get the flag for normalizing the gaussian over scale-space.

This flag enables the analysis of the differential shape of features independent of their size ( both pixels and physical size ). Following the notation of Tony Lindeberg:

Let

\[ L(x; t) = g(x; t) \ast f(x) \]

be the scale-space representation of image

\[ f(x) \]

where

\[ g(x; t) = \frac{1}{ \sqrt{ 2 \pi t} } \exp{ \left( -\frac{x^2}{ 2 t } \right) } \]

is the Gaussian function and

\[\ast\]

denotes convolution. This is a change from above with

\[ t = \sigma^2 \]

.

Then the normalized derivative operator for normalized coordinates across scale is:

\[ \partial_\xi = \sqrt{t} \partial_x \]

The resulting scaling factor is

\[ \sigma^N \]

where N is the order of the derivative.

When this flag is ON the filter will be normalized in such a way that the values of derivatives are not biased by the size of the object. That is to say the maximum value a feature reaches across scale is independent of the scale of the object.

For analyzing an image across scale-space you want to enable this flag. It is disabled by default.

Note: Not all scale space axioms are satisfied by this filter, some are only approximated. Particularly, at fine scales ( say less than 1 pixel ) other methods such as a discrete Gaussian kernel should be considered.

Definition at line 96 of file sitkRecursiveGaussianImageFilter.h.

◆ SetOrder()

Self& itk::simple::RecursiveGaussianImageFilter::SetOrder ( OrderType Order )

inline

     Set/Get the Order of the Gaussian to convolve with.

ZeroOrder is equivalent to convolving with a Gaussian. This is the default.

FirstOrder is equivalent to convolving with the first derivative of a Gaussian.

SecondOrder is equivalent to convolving with the second derivative of a Gaussian.

Definition at line 119 of file sitkRecursiveGaussianImageFilter.h.

◆ SetSigma()

Self& itk::simple::RecursiveGaussianImageFilter::SetSigma ( double Sigma )

inline

Set/Get the Sigma, measured in world coordinates, of the Gaussian kernel. The default is 1.0. An exception will be generated if the Sigma value is less than or equal to zero.

Definition at line 70 of file sitkRecursiveGaussianImageFilter.h.