#include <itkLevelSetMotionRegistrationFilter.h>

Inheritance diagram for itk::LevelSetMotionRegistrationFilter< TFixedImage, TMovingImage, TDisplacementField >:

Collaboration diagram for itk::LevelSetMotionRegistrationFilter< TFixedImage, TMovingImage, TDisplacementField >:

Public Types
typedef SmartPointer< const Self >	ConstPointer
typedef Superclass::DisplacementFieldPointer	DisplacementFieldPointer
typedef Superclass::DisplacementFieldType	DisplacementFieldType
typedef Superclass::FiniteDifferenceFunctionType	FiniteDifferenceFunctionType
typedef Superclass::FixedImagePointer	FixedImagePointer
typedef Superclass::FixedImageType	FixedImageType
typedef LevelSetMotionRegistrationFunction < FixedImageType, MovingImageType, DisplacementFieldType >	LevelSetMotionFunctionType
typedef Superclass::MovingImagePointer	MovingImagePointer
typedef Superclass::MovingImageType	MovingImageType
typedef SmartPointer< Self >	Pointer
typedef LevelSetMotionRegistrationFilter	Self
typedef PDEDeformableRegistrationFilter < TFixedImage, TMovingImage, TDisplacementField >	Superclass
typedef Superclass::TimeStepType	TimeStepType
Public Member Functions
virtual ::itk::LightObject::Pointer	CreateAnother (void) const
virtual double	GetAlpha () const
virtual double	GetGradientMagnitudeThreshold () const
virtual double	GetGradientSmoothingStandardDeviations () const
virtual double	GetIntensityDifferenceThreshold () const
virtual double	GetMetric () const
virtual const char *	GetNameOfClass () const
virtual void	SetAlpha (double)
virtual void	SetGradientMagnitudeThreshold (double)
virtual void	SetGradientSmoothingStandardDeviations (double sigma)
virtual void	SetIntensityDifferenceThreshold (double)
Static Public Member Functions
static Pointer	New ()
Protected Member Functions
virtual void	ApplyUpdate (const TimeStepType &dt)
virtual bool	Halt ()
virtual void	InitializeIteration ()
	LevelSetMotionRegistrationFilter ()
void	PrintSelf (std::ostream &os, Indent indent) const
	~LevelSetMotionRegistrationFilter ()
Private Member Functions
	LevelSetMotionRegistrationFilter (const Self &)
void	operator= (const Self &)

Detailed Description

template<class TFixedImage, class TMovingImage, class TDisplacementField>
class itk::LevelSetMotionRegistrationFilter< TFixedImage, TMovingImage, TDisplacementField >

Deformably register two images using level set motion.

LevelSetMotionFilter implements a deformable registration algorithm that aligns a fixed and a moving image under level set motion. The equations of motion are similar to those of the DemonsRegistrationFilter. The main differences are: (1) Gradients of the moving image are calculated on a smoothed image while intensity difference are measured on the original images (2) Magnitude of the motion vector is a function of the differences in intensity between the fixed and moving pixel. An adaptive timestep is calculated based on the maximum motion vector over the entire field to ensure stability. The timestep also implictly converts the motion vector measured in units of intensity to a vector measured in physical units. Demons, on the other hand, defines its motion vectors as function of both the intensity differences and gradient magnitude at each respective pixel. Consider two separate pixels with the same intensity differences between the corresponding fixed and moving pixel pairs. In demons, the motion vector of the pixel over a low gradient region will be larger than the motion vector of the pixel over a large gradient region. This leads to an unstable vector field. In the levelset approach, the motion vectors will be proportional to the gradients, scaled by the maximum gradient over the entire field. The pixel with at the lower gradient position will more less than the pixel at the higher gradient position. (3) Gradients are calculated using minmod finite difference instead of using central differences.

A deformation field is represented as a image whose pixel type is some vector type with at least N elements, where N is the dimension of the fixed image. The vector type must support element access via operator []. It is assumed that the vector elements behave like floating point scalars.

This class is templated over the fixed image type, moving image type and the deformation field type.

The input fixed and moving images are set via methods SetFixedImage and SetMovingImage respectively. An initial deformation field maybe set via SetInitialDisplacementField or SetInput. If no initial field is set, a zero field is used as the initial condition.

The algorithm has one parameters: the number of iteration to be performed.

The output deformation field can be obtained via methods GetOutput or GetDisplacementField.

This class make use of the finite difference solver hierarchy. Update for each iteration is computed in LevelSetMotionFunction.

Warning:: This filter assumes that the fixed image type, moving image type and deformation field type all have the same number of dimensions.

Ref: B.C. Vemuri, J. Ye, Y. Chen, C.M. Leonard. "Image registration via level-set motion: applications to atlas-based segmentation". Medical Image Analysis. Vol. 7. pp. 1-20. 2003.

See also:: LevelSetMotionRegistrationFunction; DemonsRegistrationFilter

Definition at line 91 of file itkLevelSetMotionRegistrationFilter.h.