Inheritance diagram for itk::UnsharpMaskLevelSetImageFilter< TInputImage, TOutputImage >:

Collaboration diagram for itk::UnsharpMaskLevelSetImageFilter< TInputImage, TOutputImage >:

Public Types
typedef SmartPointer< const Self >	ConstPointer
typedef LevelSetFunctionWithRefitTerm < TOutputImage, SparseImageType >	FunctionType
typedef SmartPointer< Self >	Pointer
typedef FunctionType::RadiusType	RadiusType
typedef UnsharpMaskLevelSetImageFilter	Self
typedef Superclass::SparseImageType	SparseImageType
typedef SparseFieldFourthOrderLevelSetImageFilter < TInputImage, TOutputImage >	Superclass
Public Member Functions
virtual ::itk::LightObject::Pointer	CreateAnother (void) const
virtual unsigned int	GetMaxFilterIteration () const
virtual const char *	GetNameOfClass () const
virtual void	SetMaxFilterIteration (unsigned int _arg)
Static Public Member Functions
static Pointer	New ()
Protected Member Functions
virtual void	PrintSelf (std::ostream &os, Indent indent) const
	UnsharpMaskLevelSetImageFilter ()
	~UnsharpMaskLevelSetImageFilter ()

virtual bool	Halt ()
Protected Attributes
FunctionType::Pointer	m_Function
unsigned int	m_MaxFilterIteration
Private Member Functions
void	operator= (const Self &)
	UnsharpMaskLevelSetImageFilter (const Self &)

Detailed Description

This class implements a detail enhancing filter by making use of the 4th-order level set isotropic diffusion (smoothing) PDE.

INPUT and OUTPUT: This is a volume to volume filter; however, it is meant to process (smooth) surfaces. The input surface is an isosurface of the input volume. The isosurface value to be processed can be set by calling SetIsoSurfaceValue (default is 0). The output surface is the 0-isosurface of the output volume, regardless of the input isosurface value. To visualize the input/output surfaces to this filter a mesh extraction method such as marching cubes can be used.

: This filter is an example of how the 4th order level set PDE framework can be used for general purpose surface processing. It is motivated by unsharp masking from image processing which is a way of enhancing detail. This filter acts much like the IsotropicFourthOrderLevelSetImageFilter because it first smoothes the normal vectors via isotropic diffusion. However, as a post-processing step we extrapolate from the original normals in the direction opposite to the new processes normals. By refiting the surface to these extrapolated vectors we achieve detail enhancement. This process is not the same as running the isotropic diffusion process in reverse.

IMPORTANT: Because this filters enhances details on the surface, it will also amplify noise! This filter is provided only as an example of graphics oriented post-processing. Do not use it on noisy data.

PARAMETERS: As mentioned before, the IsoSurfaceValue parameter chooses which isosurface of the input to process. The MaxFilterIterations parameter determine the number of iterations for which this filter will run. Since, this filter enhances detail AND noise MaxFilterIterations above a couple of hundred are unreasonable. Finally NormalProcessUnsharpWeight controls the amount of extrapolation (or equivalently the amount of detail enhancement). This value should be in the range [0.1,1] for reasonable results.