#include <itkLandmarkBasedTransformInitializer.h>

Inheritance diagram for itk::LandmarkBasedTransformInitializer< TTransform, TFixedImage, TMovingImage >:

Collaboration diagram for itk::LandmarkBasedTransformInitializer< TTransform, TFixedImage, TMovingImage >:

Detailed Description

template<typename TTransform, typename TFixedImage = itk::ImageBase<TTransform::InputSpaceDimension >, typename TMovingImage = itk::ImageBase<TTransform::OutputSpaceDimension>>
class itk::LandmarkBasedTransformInitializer< TTransform, TFixedImage, TMovingImage >

This class computes the transform that aligns the fixed and moving images given a set of pair landmarks. The class is templated over the Transform type as well as fixed image and moving image types. The transform computed gives the best fit transform that maps the fixed and moving images in a least squares sense. The indices are taken to correspond, so point 1 in the first set will get mapped close to point 1 in the second set, etc.

Currently, the following transforms are supported by the class: VersorRigid3DTransform Rigid2DTransform AffineTransform BSplineTransform

An equal number of fixed and moving landmarks need to be specified using SetFixedLandmarks() and SetMovingLandmarks(). Any number of landmarks may be specified. In the case of the Affine transformation the number of landmarks must be greater than the landmark dimensionality. If this is not the case an exception is thrown. In the case of the VersorRigid3DTransform and Rigid2DTransform the number of landmarks must be equal or greater than the landmark dimensionality. If this is not the case, only the translational component of the transformation is computed and the rotation is the identity. In the case of using Affine or BSpline transforms, each landmark pair can contribute in the final transform based on its defined weight. Number of weights should be equal to the number of landmarks and can be specified using SetLandmarkWeight(). By defaults are weights are set to one. Call InitializeTransform() to initialize the transform.

The class is based in part on Hybrid/vtkLandmarkTransform originally implemented in python by David G. Gobbi.

The solution is based on Berthold K. P. Horn (1987), "Closed-form solution of absolute orientation using unit quaternions," http://people.csail.mit.edu/bkph/papers/Absolute_Orientation.pdf

The Affine Transform initializer is based on an algorithm by H Spaeth, and is described in the Insight Journal Article "Affine Transformation for Landmark Based Registration Initializer in ITK" by Kim E.Y., Johnson H., Williams N. available at http://midasjournal.com/browse/publication/825

Wiki Examples:

Examples:: WikiExamples/Registration/LandmarkBasedTransformInitializer.cxx.

Definition at line 88 of file itkLandmarkBasedTransformInitializer.h.

Public Types
typedef AffineTransform < ParametersValueType, FixedImageType::ImageDimension >	AffineTransformType

typedef BSplineTransform < ParametersValueType, FixedImageType::ImageDimension, SplineOrder >	BSplineTransformType

typedef SmartPointer< const Self >	ConstPointer

typedef FixedImageType::ConstPointer	FixedImagePointer

typedef TFixedImage	FixedImageType

typedef TransformType::InputPointType	InputPointType

typedef std::vector < LandmarkPointType >	LandmarkPointContainer

typedef Point< double, ImageDimension >	LandmarkPointType

typedef LandmarkWeightType::const_iterator	LandmarkWeightConstIterator

typedef std::vector< double >	LandmarkWeightType

typedef MovingImageType::ConstPointer	MovingImagePointer

typedef TMovingImage	MovingImageType

typedef TransformType::OutputVectorType	OutputVectorType

typedef TransformType::ParametersType	ParametersType

typedef ParametersType::ValueType	ParametersValueType

typedef SmartPointer< Self >	Pointer

typedef LandmarkPointContainer::const_iterator	PointsContainerConstIterator

typedef Rigid2DTransform < ParametersValueType >	Rigid2DTransformType

typedef LandmarkBasedTransformInitializer	Self

typedef Object	Superclass

typedef TransformType::Pointer	TransformPointer

typedef TTransform	TransformType

typedef VersorRigid3DTransform < ParametersValueType >	VersorRigid3DTransformType

Public Types inherited from itk::Object
typedef SmartPointer< const Self >	ConstPointer

typedef SmartPointer< Self >	Pointer

typedef Object	Self

typedef LightObject	Superclass

Public Types inherited from itk::LightObject
typedef SmartPointer< const Self >	ConstPointer

typedef SmartPointer< Self >	Pointer

typedef LightObject	Self

Public Member Functions
virtual ::itk::LightObject::Pointer	CreateAnother () const

virtual const char *	GetNameOfClass () const

virtual void	InitializeTransform ()

virtual void	SetBSplineNumberOfControlPoints (unsigned int _arg)

void	SetFixedLandmarks (const LandmarkPointContainer &fixedLandmarks)

void	SetLandmarkWeight (LandmarkWeightType &landmarkWeight)

void	SetMovingLandmarks (const LandmarkPointContainer &movingLandmarks)

virtual void	SetReferenceImage (const FixedImageType *_arg)

virtual void	SetTransform (TransformType *_arg)

Public Member Functions inherited from itk::Object
unsigned long	AddObserver (const EventObject &event, Command *)

unsigned long	AddObserver (const EventObject &event, Command *) const

virtual void	DebugOff () const

virtual void	DebugOn () const

Command *	GetCommand (unsigned long tag)

bool	GetDebug () const

MetaDataDictionary &	GetMetaDataDictionary ()

const MetaDataDictionary &	GetMetaDataDictionary () const

virtual ModifiedTimeType	GetMTime () const

virtual const TimeStamp &	GetTimeStamp () const

bool	HasObserver (const EventObject &event) const

void	InvokeEvent (const EventObject &)

void	InvokeEvent (const EventObject &) const

virtual void	Modified () const

virtual void	Register () const override

void	RemoveAllObservers ()

void	RemoveObserver (unsigned long tag)

void	SetDebug (bool debugFlag) const

void	SetMetaDataDictionary (const MetaDataDictionary &rhs)

virtual void	SetReferenceCount (int) override

virtual void	UnRegister () const noexceptoverride

virtual void	SetObjectName (std::string _arg)

virtual const std::string &	GetObjectName () const

Public Member Functions inherited from itk::LightObject
virtual void	Delete ()

virtual int	GetReferenceCount () const

	itkCloneMacro (Self)

void	Print (std::ostream &os, Indent indent=0) const

Static Public Member Functions
static Pointer	New ()

Static Public Member Functions inherited from itk::Object
static bool	GetGlobalWarningDisplay ()

static void	GlobalWarningDisplayOff ()

static void	GlobalWarningDisplayOn ()

static Pointer	New ()

static void	SetGlobalWarningDisplay (bool flag)

Static Public Member Functions inherited from itk::LightObject
static void	BreakOnError ()

static Pointer	New ()

Static Public Attributes
static const unsigned int	ImageDimension = FixedImageType::ImageDimension

static const unsigned int	SplineOrder = 3


static const unsigned int	InputSpaceDimension = TransformType::InputSpaceDimension

static const unsigned int	OutputSpaceDimension = TransformType::OutputSpaceDimension

Protected Member Functions
	LandmarkBasedTransformInitializer ()

virtual void	PrintSelf (std::ostream &os, Indent indent) const override

	~LandmarkBasedTransformInitializer () override

Protected Member Functions inherited from itk::Object
	Object ()

bool	PrintObservers (std::ostream &os, Indent indent) const

virtual void	SetTimeStamp (const TimeStamp &time)

virtual	~Object () override

Protected Member Functions inherited from itk::LightObject
virtual LightObject::Pointer	InternalClone () const

	LightObject ()

virtual void	PrintHeader (std::ostream &os, Indent indent) const

virtual void	PrintTrailer (std::ostream &os, Indent indent) const

virtual	~LightObject ()

Private Member Functions
template<typename TTransform2 >
void	InternalInitializeTransform (TTransform2 *)

void	InternalInitializeTransform (VersorRigid3DTransformType *)

void	InternalInitializeTransform (Rigid2DTransformType *)

void	InternalInitializeTransform (AffineTransformType *)

void	InternalInitializeTransform (BSplineTransformType *)

Private Attributes
unsigned int	m_BSplineNumberOfControlPoints

LandmarkPointContainer	m_FixedLandmarks

LandmarkWeightType	m_LandmarkWeight

LandmarkPointContainer	m_MovingLandmarks

FixedImagePointer	m_ReferenceImage

TransformPointer	m_Transform

Additional Inherited Members
Protected Attributes inherited from itk::LightObject
AtomicInt< int >	m_ReferenceCount