#include <PointCorrespondenceDistance.h>

Inheritance diagram for mirtk::PointCorrespondenceDistance:

Collaboration diagram for mirtk::PointCorrespondenceDistance:

Public Member Functions
bool	DoEvaluateSourceError () const
	Whether to evaluate source to target error.

bool	DoEvaluateTargetError () const
	Whether to evaluate target to source error.

virtual void	Initialize ()
	Initialize error measure once input and parameters have been set.

PointCorrespondenceDistance &	operator= (const PointCorrespondenceDistance &)
	Assignment operator.

virtual ParameterList	Parameter () const
	Get parameter key/value as string map.

	PointCorrespondenceDistance (const char *="", double=1.0)
	Constructor.

	PointCorrespondenceDistance (const PointCorrespondenceDistance &)
	Copy constructor.

virtual void	Reinitialize ()
	Reinitialize error measure after change of input topology.

virtual void	Update (bool=true)
	Update moving input points and internal state of distance measure.

virtual bool	Upgrade ()
	Update energy term after convergence.

virtual void	WriteDataSets (const char , const char , bool=true) const
	Write input of data fidelity term.

virtual void	WriteGradient (const char , const char ) const
	Write gradient of data fidelity term w.r.t each transformed input.

virtual	~PointCorrespondenceDistance ()
	Destructor.

Public Member Functions inherited from mirtk::PointSetDistance
virtual	~PointSetDistance ()
	Destructor.

Public Member Functions inherited from mirtk::DataFidelity
virtual	~DataFidelity ()
	Destructor.

Public Member Functions inherited from mirtk::EnergyTerm
virtual enum EnergyMeasure	EnergyMeasure () const =0
	Energy measure implemented by this term.

void	Gradient (double *gradient, double step)

virtual void	GradientStep (const double *gradient, double &min, double &max) const

double	InitialValue ()
	Returns initial value of energy term.

void	NormalizedGradient (double *gradient, double step)

string	Prefix (const char *=NULL) const
	Prefix to be used for debug output files.

virtual void	Print (Indent=0) const
	Print debug information.

virtual double	RawValue (double) const

double	RawValue ()

void	ResetInitialValue ()
	Reset initial value of energy term.

void	ResetValue ()
	Reset cached value of energy term.

double	Value ()
	Evaluate energy term.

virtual	~EnergyTerm ()
	Destructor.

Public Member Functions inherited from mirtk::Configurable
string	DefaultName () const

virtual bool	Set (const char , const char )
	Set parameter value from string.

virtual	~Configurable ()
	Destructor.

Public Member Functions inherited from mirtk::Observable
void	AddObserver (Observer &)
	Add observer.

void	Broadcast (Event, const void *=NULL)
	Broadcast event to observers.

void	ClearObservers ()
	Delete all observers.

void	DeleteObserver (Observer &)
	Delete observer.

void	NotifyObservers (Event, const void *=NULL)
	Notify all observers about given event if this object has changed.

int	NumberOfObservers () const
	Number of current observers.

virtual	~Observable ()
	Destructor.

Public Member Functions inherited from mirtk::Object
virtual const char *	NameOfClass () const =0
	Get name of class, which this object is an instance of.

bool	Parameter (const ParameterList &)
	Set parameters from name/value pairs.

virtual	~Object ()
	Destructor.

Protected Member Functions
virtual double	Evaluate ()
	Evaluate unweighted energy term.

void	EvaluateGradient (double *gradient, double step, double weight)

void	ForwardEvent (Observable , Event, const void )
	Forward point correspondence map event.

	mirtkAttributeMacro (Array< int >, TargetSample)
	Indices of sampled target points.

	mirtkAttributeMacro (Array< int >, SourceSample)
	Indices of sampled source points.

	mirtkAttributeMacro (int, NumberOfUpdates)
	Number of invocations of Update modulo _UpdatePeriod.

	mirtkComponentMacro (PointCorrespondence, Correspondence)
	Point correspondence map.

	mirtkComponentMacro (RadialErrorFunction, ErrorFunction)
	Polydata registration error weight function.

	mirtkPublicAttributeMacro (double, TargetSampleDistance)
	Approximate distance between sampled target points.

	mirtkPublicAttributeMacro (double, SourceSampleDistance)
	Approximate distance between sampled source points.

	mirtkPublicAttributeMacro (int, NumberOfTargetSamples)
	Maximum number of target samples used.

	mirtkPublicAttributeMacro (int, NumberOfSourceSamples)
	Maximum number of target samples used.

	mirtkPublicAttributeMacro (int, UpdatePeriod)
	Number of Update calls between reevaluation of correspondences.

	mirtkPublicAttributeMacro (bool, EvaluateTargetError)
	Whether to evaluate error of target points and corresponding source points.

	mirtkPublicAttributeMacro (bool, EvaluateSourceError)
	Whether to evaluate error of source points and corresponding target points.

virtual void	NonParametricGradient (const RegisteredPointSet source, GradientType gradient)

virtual void	ParametricGradient (const RegisteredPointSet source, const GradientType np_gradient, double *gradient, double weight)

	PointCorrespondenceDistance (const char , double, PointCorrespondence , RadialErrorFunction *=NULL)
	Construct distance with given default point correspondence type and error function.

void	SamplePoints ()
	Sample point sets.

virtual bool	SetWithoutPrefix (const char , const char )
	Set parameter value from string.

virtual void	WriteDataSet (const char , const RegisteredPointSet , const Array< int > &, const PointCorrespondence *) const
	Write given input data set to specified file.

Protected Member Functions inherited from mirtk::PointSetDistance
void	AllocateGradientWrtSource (int)
	Allocate memory for (non-parametric) gradient w.r.t points of source.

void	AllocateGradientWrtTarget (int)
	Allocate memory for (non-parametric) gradient w.r.t points of target.

void	CopyAttributes (const PointSetDistance &, int=-1, int=-1)
	Copy attributes from other point set distance measure.

void	Initialize (int, int)
	Initialize distance measure once input and parameters have been set.

	mirtkAttributeMacro (bool, InitialUpdate)
	Whether Update has not been called since initialization.

	mirtkComponentMacro (GradientType, GradientWrtTarget)
	Memory for (non-parametric) gradient w.r.t points of target.

	mirtkComponentMacro (GradientType, GradientWrtSource)
	Memory for (non-parametric) gradient w.r.t points of source.

	mirtkPublicAggregateMacro (RegisteredPointSet, Target)
	First point set.

	mirtkPublicAggregateMacro (RegisteredPointSet, Source)
	Second point set.

PointSetDistance &	operator= (const PointSetDistance &)
	Assignment operator.

	PointSetDistance (const char *="", double=1.0)
	Constructor.

	PointSetDistance (const PointSetDistance &, int=-1, int=-1)
	Copy constructor.

void	Reinitialize (int, int)

virtual void	WriteGradient (const char , const RegisteredPointSet , const GradientType , const Array< int > =NULL) const
	Write gradient of data fidelity term w.r.t each transformed input.

Protected Member Functions inherited from mirtk::DataFidelity
	DataFidelity (const char *="", double=1.0)
	Constructor.

	DataFidelity (const DataFidelity &)
	Copy constructor.

DataFidelity &	operator= (const DataFidelity &)
	Assignment operator.

virtual bool	SetWithPrefix (const char , const char )
	Set parameter value from string.

Protected Member Functions inherited from mirtk::EnergyTerm
	EnergyTerm (const char *="", double=1.0)
	Constructor.

	EnergyTerm (const EnergyTerm &)
	Copy constructor.

EnergyTerm &	operator= (const EnergyTerm &)
	Assignment operator.

Protected Member Functions inherited from mirtk::Configurable
	Configurable (const char *="")
	Constructor.

	Configurable (const Configurable &)
	Copy constructor.

string	DefaultPrefix () const
	Get default object name prefix (if any)

bool	HasName () const
	Whether this object has an explicit name.

bool	HasPrefix () const
	Whether this object has either an explicit name or default prefix.

template<class T >
bool	InsertWithPrefix (ParameterList &, string, T) const
	Insert parameter into name/value list with object name prefix.

bool	InsertWithPrefix (ParameterList &, const ParameterList &) const
	Insert parameters into name/value list with object name prefix.

Configurable &	operator= (const Configurable &)
	Assignment operator.

string	ParameterNameWithoutPrefix (const char *) const
	Get name of parameter without object name prefix.

string	ParameterNameWithPrefix (const string &) const
	Get name of parameter with default object name prefix.

string	ParameterNameWithPrefix (const char *) const
	Get name of parameter with default object name prefix.

Protected Member Functions inherited from mirtk::Observable
	Observable ()
	Default constructor.

	Observable (const Observable &)
	Copy constructor.

Observable &	operator= (const Observable &)
	Assignment operator.

Protected Member Functions inherited from mirtk::Object
template<typename... Args>
void	Throw (ErrorType err, const char *func, Args... args) const

Protected Attributes
EventDelegate	_EventDelegate
	Forwards correspondence map event messages to observers of energy term.

Additional Inherited Members
Public Types inherited from mirtk::PointSetDistance
typedef Vector3D< double >	GradientType
	Type of gradient w.r.t a single transformed data point.

Public Types inherited from mirtk::EnergyTerm
typedef ObjectFactory< enum EnergyMeasure, EnergyTerm >	FactoryType
	Type of energy term factory.

Static Public Member Functions inherited from mirtk::PointSetDistance
static PointSetDistance *	New (PointSetDistanceMeasure, const char *="", double=1.0)
	Instantiate specified similarity measure.

Static Public Member Functions inherited from mirtk::EnergyTerm
static FactoryType &	Factory ()
	Get global energy term factory instance.

static EnergyTerm *	New (EnergyMeasure, const char *="", double=1.0)
	Construct new energy term.

static EnergyTerm *	TryNew (EnergyMeasure, const char *="", double=1.0)
	Construct new energy term or return nullptr if term not available.

Static Public Member Functions inherited from mirtk::Object
static const char *	NameOfType ()
	Get name of this class type.

Static Protected Member Functions inherited from mirtk::Object
template<typename... Args>
static void	ThrowStatic (ErrorType err, const char cls, const char func, Args... args)

Detailed Description

Distance error of established/known point correspondences

This distance term evaluates the residual registration error of each transformed target point relative to its corresponding source point. It is a generic point set distance measure which can be used for many types of point sets, including in particular point clouds, curves, and surface meshes.

A corresponding point locator is utilized to find the corresponding point in the source data set. This can be, for example, the closest point in the source data set, the closest point on the source surface, or the matched source data set point which is closest in terms of some other feature than just Euclidean distance of the points. A special case of point correspondence is one which remains fixed and maps the i-th point in the target data set to the j-th point in the source data set. This is the case for manually labeled fiducial markers (cf. FiducialRegistrationError) or pre-computed correspondence maps using an external point/surface matching algorithm.

The Euclidean distance of corresponding points is further weighted by an error function which may non-linearly penalize established correspondences and reduce influence of outliers or incorrect matches in order to improve the robustness of the point set registration.

Definition at line 63 of file PointCorrespondenceDistance.h.

Member Function Documentation

§ EvaluateGradient()

void mirtk::PointCorrespondenceDistance::EvaluateGradient	(	double *	gradient,
		double	step,
		double	weight
	)

protectedvirtual

Evaluate gradient of point distance measure

This function calls the virtual NonParametricGradient function to be implemented by subclasses for each transformed input data set to obtain the gradient of the point set distance measure. It then converts this gradient into a gradient w.r.t the transformation parameters using the ParametricGradient.

If both target and source data sets are transformed by different transformations, the resulting gradient vector contains first the derivative values w.r.t the parameters of the target transformation followed by those computed w.r.t the parameters of the source transformation. If both data sets are transformed by the same transformation, the sum of the derivative values is added to the resulting gradient vector. This is in particular the case for a velocity based transformation model which is applied to deform both data sets "mid-way". Otherwise, only one input data set is transformed (usually the target) and the derivative values of only the respective transformation parameters added to the gradient vector.

See also: NonParametricGradient, ParametricGradient

Parameters

[in,out]	gradient	Gradient to which the computed gradient of the point set distance measure is added after multiplying by the given similarity `weight`.
[in]	step	Step length for finite differences (unused).
[in]	weight	Weight of point set distance measure.

Reimplemented from mirtk::PointSetDistance.

§ NonParametricGradient()

virtual void mirtk::PointCorrespondenceDistance::NonParametricGradient	(	const RegisteredPointSet *	source,
		GradientType *	gradient
	)

protectedvirtual

Compute non-parametric gradient w.r.t the given point set

Parameters

[in]	source	Set of transformed fiducial points.
[out]	gradient	Non-parametric fiducial registration error gradient.

Implements mirtk::PointSetDistance.

§ ParametricGradient()

virtual void mirtk::PointCorrespondenceDistance::ParametricGradient	(	const RegisteredPointSet *	source,
		const GradientType *	np_gradient,
		double *	gradient,
		double	weight
	)

protectedvirtual

Convert non-parametric gradient of point set distance measure into gradient w.r.t transformation parameters

This function calls Transformation::ParametricGradient of the transformation to apply the chain rule in order to obtain the gradient of the distance measure w.r.t the transformation parameters. It adds the weighted gradient to the final registration energy gradient.

Parameters

[in]	source	Transformed point set.
[in]	np_gradient	Point-wise non-parametric gradient.
[in,out]	gradient	Gradient to which the computed parametric gradient is added, after multiplication by the given `weight`.
[in]	weight	Weight of point set distance measure.

Reimplemented from mirtk::PointSetDistance.

The documentation for this class was generated from the following file:

PointCorrespondenceDistance.h

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation

§ EvaluateGradient()

§ NonParametricGradient()

§ ParametricGradient()