A kernel filter with variable kurtosis. More...

#include <VariableShapeFilter.h>

Inheritance diagram for pcl::VariableShapeFilter:

Public Member Functions
	VariableShapeFilter ()=default

	VariableShapeFilter (const VariableShapeFilter &)=default

	VariableShapeFilter (float sigma, float shape, float epsilon, float rho, float theta=0, const String &name=String())

	VariableShapeFilter (float sigma, float shape=2, float epsilon=0.01, const String &name=String())

	VariableShapeFilter (int n, float shape, float epsilon, float rho, float theta=0, const String &name=String())

	VariableShapeFilter (int n, float shape=2, float epsilon=0.01, const String &name=String())

	VariableShapeFilter (VariableShapeFilter &&)=default

float	AspectRatio () const

SeparableFilter	AsSeparableFilter (float tolerance=__PCL_DEFAULT_FILTER_SEPARABILITY_TOLERANCE) const override

KernelFilter *	Clone () const override

double	FWHM () const

double	FWHMx () const

double	FWHMy () const

bool	IsSeparable () const override

VariableShapeFilter &	operator= (const VariableShapeFilter &)=default

VariableShapeFilter &	operator= (VariableShapeFilter &&)=default

void	Resize (int n) override

float	RotationAngle () const

void	Set (float sigma)

void	Set (float sigma, float shape)

void	Set (float sigma, float shape, float epsilon)

void	Set (float sigma, float shape, float epsilon, float rho)

void	Set (float sigma, float shape, float epsilon, float rho, float theta)

void	SetAspectRatio (float rho)

void	SetRotationAngle (float theta)

void	SetShape (float shape)

void	SetSigma (float sigma)

void	SetTruncation (float epsilon)

float	Shape () const

float	Sigma () const

float	SigmaX () const

float	SigmaY () const

float	Truncation () const

Public Member Functions inherited from pcl::KernelFilter
	KernelFilter (const coefficient_matrix &F, const String &name=String())

	KernelFilter (const KernelFilter &)=default

	KernelFilter (const String &name=String())

template<typename T >
	KernelFilter (const T *k, int n, const String &name=String())

	KernelFilter (int n, const String &name=String())

template<typename T >
	KernelFilter (int n, const T &x, const String &name=String())

	KernelFilter (KernelFilter &&)=default

virtual	~KernelFilter ()

const coefficient *	Begin () const

const coefficient *	begin () const

virtual void	Clear ()

coefficient_matrix	Coefficients () const

const coefficient *	End () const

const coefficient *	end () const

void	Flip ()

KernelFilter	Flipped () const

bool	IsEmpty () const

bool	IsFlipped () const

bool	IsHighPassFilter () const

double	Modulus () const

String	Name () const

void	Normalize ()

KernelFilter	Normalized () const

int	NumberOfCoefficients () const

	operator bool () const

KernelFilter &	operator= (const coefficient &x)

KernelFilter &	operator= (const coefficient_matrix &F)

KernelFilter &	operator= (const KernelFilter &)=default

KernelFilter &	operator= (KernelFilter &&)=default

bool	operator== (const KernelFilter &f) const

const coefficient *	operator[] (int row) const

virtual void	Rename (const String &newName)

bool	SameCoefficients (const KernelFilter &f) const

int	Size () const

template<class P >
void	ToImage (GenericImage< P > &image) const

void	ToImage (ImageVariant &v) const

double	Weight () const

Additional Inherited Members
Public Types inherited from pcl::KernelFilter
using	coefficient = float

using	coefficient_matrix = GenericMatrix< coefficient >

Detailed Description

A VariableShapeFilter object is a specialized KernelFilter whose elements are calculated as a discrete representation of the following elliptical function centered at the origin:

G(x,y) = Exp( -( x^k/(k*sx^k) + y^k/(k*sy^k) ) )

where sx and sy are the standard deviations of the filter distribution on the horizontal and vertical axes, respectively, and k is a shape parameter controlling the kurtosis of the filter function. When k < 2 the distribution is leptokurtic (peaked), while k > 2 leads to a platykurtic (flat) distribution. When k = 2 the distribution is normal (Gaussian) and the VariableShapeFilter is equivalent to a GaussianFilter object with the same standard deviations.

VariableShapeFilter also supports arbitrary rotation around the origin. When the filter is rotated, the coordinates x, y in the equation above are replaced by their rotated counterparts.

A VariableShapeFilter instance is formally defined by the following set of parameters:

sigma	Standard deviation of the filter distribution on the X axis (sigma > 0).
shape	Filter shape: 2 = Gaussian, < 2 = leptokurtic, > 2 = platykurtic (shape > 0).
rho	The ratio sy/sx (see equation above) of the generated filter distribution (0 ≤ rho ≤ 1).
theta	Rotation angle of the horizontal axis in radians (0 ≤ theta < PI). This parameter only makes sense when rho < 1.
epsilon	Maximum truncation error of the computed filter coefficients (eps > 0).

See also: KernelFilter, GaussianFilter, MoffatFilter, LinearFilter

Definition at line 104 of file VariableShapeFilter.h.

Constructor & Destructor Documentation

◆ VariableShapeFilter() [1/7]

pcl::VariableShapeFilter::VariableShapeFilter ( )

default

Constructs an empty VariableShapeFilter object with default functional parameters: sigma=2, shape=2, epsilon=0.01, rho=1, theta=0.

◆ VariableShapeFilter() [2/7]

pcl::VariableShapeFilter::VariableShapeFilter	(	float	sigma,
		float	shape = `2`,
		float	epsilon = `0.01`,
		const String &	name = `String()`
	)

inline

Constructs a VariableShapeFilter object given the standard deviation sigma > 0, shape > 0, and coefficient truncation epsilon > 0. Assigns an optional name to the new filter object.

Definition at line 119 of file VariableShapeFilter.h.

◆ VariableShapeFilter() [3/7]

pcl::VariableShapeFilter::VariableShapeFilter	(	float	sigma,
		float	shape,
		float	epsilon,
		float	rho,
		float	theta = `0`,
		const String &	name = `String()`
	)

inline

Constructs a VariableShapeFilter object given the standard deviation sigma > 0, shape > 0, coefficient truncation error epsilon > 0, aspect ratio 0 <= rho <= 1, and rotation angle 0 <= theta <= PI in radians. Assigns an optional name to the new filter object.

Definition at line 131 of file VariableShapeFilter.h.

◆ VariableShapeFilter() [4/7]

pcl::VariableShapeFilter::VariableShapeFilter	(	int	n,
		float	shape = `2`,
		float	epsilon = `0.01`,
		const String &	name = `String()`
	)

inline

Constructs a VariableShapeFilter object given the odd kernel size n >= 3, shape > 0, and coefficient truncation error epsilon > 0. Assigns an optional name to the new filter object.

Definition at line 142 of file VariableShapeFilter.h.

◆ VariableShapeFilter() [5/7]

pcl::VariableShapeFilter::VariableShapeFilter	(	int	n,
		float	shape,
		float	epsilon,
		float	rho,
		float	theta = `0`,
		const String &	name = `String()`
	)

inline

Constructs a VariableShapeFilter object given the odd kernel size n >= 3, shape > 0, coefficient truncation epsilon > 0, aspect ratio 0 <= rho <= 1, and rotation angle 0 <= theta <= PI in radians. Assigns an optional name to the new filter object.

Definition at line 154 of file VariableShapeFilter.h.

◆ VariableShapeFilter() [6/7]

pcl::VariableShapeFilter::VariableShapeFilter ( const VariableShapeFilter & )

default

Copy constructor.

◆ VariableShapeFilter() [7/7]

pcl::VariableShapeFilter::VariableShapeFilter ( VariableShapeFilter && )

default

Move constructor.

Member Function Documentation

◆ AspectRatio()

float pcl::VariableShapeFilter::AspectRatio ( ) const

inline

Returns the aspect ratio of the filter distribution. This is the ratio vertical:horizontal between filter axes in the range [0,1].

Definition at line 276 of file VariableShapeFilter.h.

◆ AsSeparableFilter()

SeparableFilter pcl::VariableShapeFilter::AsSeparableFilter ( float tolerance = __PCL_DEFAULT_FILTER_SEPARABILITY_TOLERANCE ) const

inlineoverridevirtual

Returns a separable filter equivalent to this VariableShapeFilter object.

A VariableShapeFilter is separable when it represents an undistorted Gaussian distribution. This is only true when shape=2 and the filter is circular (rho=1). Otherwise an empty SeparableFilter object is returned because this filter is not separable.

Reimplemented from pcl::KernelFilter.

Definition at line 188 of file VariableShapeFilter.h.

◆ Clone()

KernelFilter* pcl::VariableShapeFilter::Clone ( ) const

inlineoverridevirtual

Returns a pointer to a dynamically allocated duplicate of this kernel filter.

Reimplemented from pcl::KernelFilter.

Definition at line 174 of file VariableShapeFilter.h.

◆ FWHM()

double pcl::VariableShapeFilter::FWHM ( ) const

inline

Returns the full width at half maximum, in sigma units, for the horizontal axis of the elliptical filter distribution.

This function is an alias to FWHMx().

Definition at line 317 of file VariableShapeFilter.h.

◆ FWHMx()

double pcl::VariableShapeFilter::FWHMx ( ) const

inline

Returns the full width at half maximum (FWHM), in sigma units, for the horizontal axis of the elliptical filter distribution.

Definition at line 295 of file VariableShapeFilter.h.

References pcl::Pow().

◆ FWHMy()

double pcl::VariableShapeFilter::FWHMy ( ) const

inline

Returns the full width at half maximum (FWHM), in sigma units, for the vertical axis of the elliptical filter distribution.

Definition at line 305 of file VariableShapeFilter.h.

◆ IsSeparable()

bool pcl::VariableShapeFilter::IsSeparable ( ) const

inlineoverridevirtual

Returns true iff this filter is separable.

A VariableShapeFilter is separable only when it represents an undistorted Gaussian distribution. This is only true when shape=2 and the filter is circular (rho=1).

Reimplemented from pcl::KernelFilter.

Definition at line 205 of file VariableShapeFilter.h.

◆ operator=() [1/2]

VariableShapeFilter& pcl::VariableShapeFilter::operator= ( const VariableShapeFilter & )

default

Copy assignment operator. Returns a reference to this object.

◆ operator=() [2/2]

VariableShapeFilter& pcl::VariableShapeFilter::operator= ( VariableShapeFilter && )

default

Move assignment operator. Returns a reference to this object.

◆ Resize()

void pcl::VariableShapeFilter::Resize ( int n )

inlineoverridevirtual

Recalculates filter coefficients for the given odd kernel size n >= 3. This routine computes the required standard deviation to sample the filter function on a matrix of the specified size, preserving the current shape, coefficient truncation, aspect ratio and rotation angle.

Reimplemented from pcl::KernelFilter.

Definition at line 422 of file VariableShapeFilter.h.

◆ RotationAngle()

float pcl::VariableShapeFilter::RotationAngle ( ) const

inline

Returns the rotation angle of the filter distribution. This is the rotation angle in radians with respect to the central pixel, in the range [0,+PI].

Definition at line 286 of file VariableShapeFilter.h.

◆ Set() [1/5]

void pcl::VariableShapeFilter::Set ( float sigma )

inline

Recalculates filter coefficients for the specified sigma > 0. The current shape, coefficient truncation error, aspect ratio and rotation angle are not changed.

Definition at line 367 of file VariableShapeFilter.h.

◆ Set() [2/5]

void pcl::VariableShapeFilter::Set	(	float	sigma,
		float	shape
	)

inline

Recalculates filter coefficients for the specified sigma > 0 and shape > 0. Coefficient truncation, aspect ratio and rotation angle are not changed.

Definition at line 357 of file VariableShapeFilter.h.

◆ Set() [3/5]

void pcl::VariableShapeFilter::Set	(	float	sigma,
		float	shape,
		float	epsilon
	)

inline

Recalculates filter coefficients for the specified sigma > 0, shape > 0, and coefficient truncation error epsilon > 0. Does not change the current aspect ratio and rotation angle.

Definition at line 347 of file VariableShapeFilter.h.

◆ Set() [4/5]

void pcl::VariableShapeFilter::Set	(	float	sigma,
		float	shape,
		float	epsilon,
		float	rho
	)

inline

Recalculates filter coefficients for the specified sigma > 0, shape > 0, coefficient truncation error epsilon > 0, and aspect ratio 0 <= rho <= 1. Does not change the current rotation angle.

Definition at line 337 of file VariableShapeFilter.h.

◆ Set() [5/5]

void pcl::VariableShapeFilter::Set	(	float	sigma,
		float	shape,
		float	epsilon,
		float	rho,
		float	theta
	)

inline

Recalculates filter coefficients for the specified sigma > 0, shape > 0, coefficient truncation error epsilon > 0, aspect ratio 0 <= rho <= 1, and rotation angle 0 <= theta <= PI in radians.

Definition at line 327 of file VariableShapeFilter.h.

◆ SetAspectRatio()

void pcl::VariableShapeFilter::SetAspectRatio ( float rho )

inline

This is a convenience member function, equivalent to Set( Sigma(), Shape(), Truncation(), rho ).

Definition at line 402 of file VariableShapeFilter.h.

◆ SetRotationAngle()

void pcl::VariableShapeFilter::SetRotationAngle ( float theta )

inline

This is a convenience member function, equivalent to Set( Sigma(), Shape(), Truncation(), AspectRatio(), theta ).

Definition at line 411 of file VariableShapeFilter.h.

◆ SetShape()

void pcl::VariableShapeFilter::SetShape ( float shape )

inline

This is a convenience member function, equivalent to Set( Sigma(), shape ).

Definition at line 384 of file VariableShapeFilter.h.

◆ SetSigma()

void pcl::VariableShapeFilter::SetSigma ( float sigma )

inline

This is a convenience member function, equivalent to Set( sigma ).

Definition at line 375 of file VariableShapeFilter.h.

◆ SetTruncation()

void pcl::VariableShapeFilter::SetTruncation ( float epsilon )

inline

This is a convenience member function, equivalent to Set( Sigma(), Shape(), epsilon ).

Definition at line 393 of file VariableShapeFilter.h.

◆ Shape()

float pcl::VariableShapeFilter::Shape ( ) const

inline

Returns the shape parameter of this VariableShapeFilter object. The shape parameter controls the kurtosis of the filter distribution:

shape < 2	Leptokurtic distribution
shape = 2	Normal (Gaussian) distribution
shape > 2	Platykurtic distribution

Definition at line 259 of file VariableShapeFilter.h.

◆ Sigma()

float pcl::VariableShapeFilter::Sigma ( ) const

inline

Returns the standard deviation of the filter distribution on the X (horizontal) axis.

This function is an alias to SigmaX().

Definition at line 244 of file VariableShapeFilter.h.

◆ SigmaX()

float pcl::VariableShapeFilter::SigmaX ( ) const

inline

Returns the standard deviation of the filter distribution on the X (horizontal) axis.

Definition at line 224 of file VariableShapeFilter.h.

◆ SigmaY()

float pcl::VariableShapeFilter::SigmaY ( ) const

inline

Returns the standard deviation of the filter distribution on the Y (vertical) axis.

Definition at line 233 of file VariableShapeFilter.h.

◆ Truncation()

float pcl::VariableShapeFilter::Truncation ( ) const

inline

Returns the maximum truncation error of calculated filter coefficients.

Definition at line 267 of file VariableShapeFilter.h.

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

VariableShapeFilter.h

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ VariableShapeFilter() [1/7]

◆ VariableShapeFilter() [2/7]

◆ VariableShapeFilter() [3/7]

◆ VariableShapeFilter() [4/7]

◆ VariableShapeFilter() [5/7]

◆ VariableShapeFilter() [6/7]

◆ VariableShapeFilter() [7/7]

Member Function Documentation

◆ AspectRatio()

◆ AsSeparableFilter()

◆ Clone()

◆ FWHM()

◆ FWHMx()

◆ FWHMy()

◆ IsSeparable()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ Resize()

◆ RotationAngle()

◆ Set() [1/5]

◆ Set() [2/5]

◆ Set() [3/5]

◆ Set() [4/5]

◆ Set() [5/5]

◆ SetAspectRatio()

◆ SetRotationAngle()

◆ SetShape()

◆ SetSigma()

◆ SetTruncation()

◆ Shape()

◆ Sigma()

◆ SigmaX()

◆ SigmaY()

◆ Truncation()