Detailed Description

Denoise an image using min/max curvature flow.

MinMaxCurvatureFlowImageFilter implements a curvature driven image denoising algorithm. Iso-brightness contours in the grayscale input image are viewed as a level set. The level set is then evolved using a curvature-based speed function:

\[ I_t = F_{\mbox{minmax}} |\nabla I| \]

where \( F_{\mbox{minmax}} = \max(\kappa,0) \) if \( \mbox{Avg}_{\mbox{stencil}}(x) \) is less than or equal to \( T_{threshold} \) and \( \min(\kappa,0) \) , otherwise. \( \kappa \) is the mean curvature of the iso-brightness contour at point \( x \) .

In min/max curvature flow, movement is turned on or off depending on the scale of the noise one wants to remove. Switching depends on the average image value of a region of radius \( R \) around each point. The choice of \( R \) , the stencil radius, governs the scale of the noise to be removed.

The threshold value \( T_{threshold} \) is the average intensity obtained in the direction perpendicular to the gradient at point \( x \) at the extrema of the local neighborhood.

This filter make use of the multi-threaded finite difference solver hierarchy. Updates are computed using a MinMaxCurvatureFlowFunction object. A zero flux Neumann boundary condition is used when computing derivatives near the data boundary.

Warning: This filter assumes that the input and output types have the same dimensions. This filter also requires that the output image pixels are of a real type. This filter works for any dimensional images, however for dimensions greater than 3D, an expensive brute-force search is used to compute the local threshold.

Reference: "Level Set Methods and Fast Marching Methods", J.A. Sethian, Cambridge Press, Chapter 16, Second edition, 1999.

See also: MinMaxCurvatureFlowFunction; CurvatureFlowImageFilter; BinaryMinMaxCurvatureFlowImageFilter; itk::simple::MinMaxCurvatureFlow for the procedural interface; itk::MinMaxCurvatureFlowImageFilter for the Doxygen on the original ITK class.

Definition at line 64 of file sitkMinMaxCurvatureFlowImageFilter.h.

Public Types
using	PixelIDTypeList = RealPixelIDTypeList

using	Self = MinMaxCurvatureFlowImageFilter

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)

std::string	GetName () const

uint32_t	GetNumberOfIterations () const

int	GetStencilRadius () const

double	GetTimeStep () const

	MinMaxCurvatureFlowImageFilter ()

Self &	SetNumberOfIterations (uint32_t NumberOfIterations)

Self &	SetStencilRadius (int StencilRadius)

Self &	SetTimeStep (double TimeStep)

std::string	ToString () const

virtual	~MinMaxCurvatureFlowImageFilter ()

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.

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

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

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

	ProcessObject ()

virtual void	RemoveAllCommands ()
	Remove all registered commands.

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
bool	m_InPlace {false}

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

uint32_t	m_NumberOfIterations {5u}

int	m_StencilRadius {2}

double	m_TimeStep {0.05}

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.

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

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

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

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

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

static void	SetGlobalDefaultNumberOfThreads (unsigned int n)

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

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)