Aim: implements an accumulator (as histograms for 1D scalars) adapted to spherical point samples. More...

#include <DGtal/geometry/tools/SphericalAccumulator.h>

Inheritance diagram for DGtal::SphericalAccumulator< TVector >:

Public Types
typedef TVector	Vector
	Vector direction types.

typedef DGtal::int32_t	Quantity
	Type to store the bin counts.

typedef size_t	Size
	Type to represent bin indexes.

typedef std::vector< Quantity >::const_iterator	ConstIterator
	Type to iterate on bin values.

typedef PointVector< 3, double >	RealVector
	Type to represent normalized vector (internal use).

Public Member Functions
	BOOST_STATIC_ASSERT (Vector::dimension==3)

	SphericalAccumulator (const Size aNphi)

	~SphericalAccumulator ()

void	addDirection (const Vector &aDir)

void	binCoordinates (const Vector &aDir, Size &posPhi, Size &posTheta) const

Quantity	count (const Size &posPhi, const Size &posTheta) const

Vector	representativeDirection (const Size &posPhi, const Size &posTheta) const

Vector	representativeDirection (ConstIterator &it) const

Quantity	samples () const

Quantity	binNumber () const

void	maxCountBin (Size &posPhi, Size &posTheta) const

void	clear ()

void	selfDisplay (std::ostream &out) const

bool	isValid () const

std::string	className () const

bool	isValidBin (const Size &posPhi, const Size &posTheta) const

void	getBinGeometry (const Size &posPhi, const Size &posTheta, RealVector &a, RealVector &b, RealVector &c, RealVector &d) const

RealVector	getBinDirection (const Size &posPhi, const Size &posTheta) const

ConstIterator	begin () const

ConstIterator	end () const

void	binCoordinates (ConstIterator &aDir, Size &posPhi, Size &posTheta) const

	SphericalAccumulator (const SphericalAccumulator &other)

SphericalAccumulator &	operator= (const SphericalAccumulator &other)

Protected Member Functions
	SphericalAccumulator ()

Private Attributes
Size	myNphi
	Number of slices in the phi direction.

Size	myNtheta
	Number of bins in the theta direction.

std::vector< Quantity >	myAccumulator
	Accumulator container.

std::vector< Vector >	myAccumulatorDir
	Accumulator reprensentative directions.

Quantity	myTotal
	Number of samples.

Quantity	myBinNumber
	Number of bins.

Size	myMaxBinPhi
	Phi coordinate of the max bin.

Size	myMaxBinTheta
	Theta coordinate of the max bin.

Detailed Description

template<typename TVector>
class DGtal::SphericalAccumulator< TVector >

Aim: implements an accumulator (as histograms for 1D scalars) adapted to spherical point samples.

Description of template class 'SphericalAccumulator'

Spherical accumulator is decomposed into 2D bins (i,j) such that:

each direction/point on the unit sphere falls in a single bin
each bin almost cover the same area on the unit sphere
each bin have a geometrical support which can be represented as a quad except for its two poles

Compared to exact geodesic covering, such spherical accumulator bins do not have the exact same area. However, it allows fast conversion between directions and bin coordinates.

Such accumulator have been demonstrated in: Borrmann, D., Elseberg, J., & Lingemann, K. (2011). The 3D Hough Transform for plane detection in point clouds: A review and a new accumulator design. 3D Research, 02003. Retrieved from http://www.springerlink.com/index/N1W040850782VR85.pdf

Usage example:

typedef Z3i::RealVector Vector;

SphericalAccumulator<Vector> accumulator(6);

  //Insert some directions
  accumulator.addDirection( Vector(0,1,0));
  accumulator.addDirection( Vector(1,-0.01,0));
  accumulator.addDirection( Vector(1,0.01,-0.01));
  accumulator.addDirection( Vector(1,-0.01,0.01));

Once the accumulator is filled up with directions, you can get the representative direction for each bin and the bin with maximal number of samples.

Furthermore, you can send the accumulator to a Viewer3D to see the bin geometry and values:

...
Viewer3D viewer;
viewer << accumulator;
...

See also: testSphericalAccumulator.cpp

Template Parameters

TVector type used to represent directions.

Definition at line 102 of file SphericalAccumulator.h.

Member Typedef Documentation

◆ ConstIterator

template<typename TVector >

std::vector<Quantity>::const_iterator DGtal::SphericalAccumulator< TVector >::ConstIterator

Type to iterate on bin values.

Definition at line 117 of file SphericalAccumulator.h.

◆ Quantity

template<typename TVector >

DGtal::int32_t DGtal::SphericalAccumulator< TVector >::Quantity

Type to store the bin counts.

Definition at line 111 of file SphericalAccumulator.h.

◆ RealVector

template<typename TVector >

PointVector<3,double> DGtal::SphericalAccumulator< TVector >::RealVector

Type to represent normalized vector (internal use).

Definition at line 120 of file SphericalAccumulator.h.

◆ Size

template<typename TVector >

size_t DGtal::SphericalAccumulator< TVector >::Size

Type to represent bin indexes.

Definition at line 114 of file SphericalAccumulator.h.

◆ Vector

template<typename TVector >

TVector DGtal::SphericalAccumulator< TVector >::Vector

Vector direction types.

Definition at line 108 of file SphericalAccumulator.h.

Constructor & Destructor Documentation

◆ SphericalAccumulator() [1/3]

template<typename TVector >

DGtal::SphericalAccumulator< TVector >::SphericalAccumulator ( const Size aNphi )

Constructs a spherical accumulator with aNphi slices along latitudes (phi spherial coordinate). The decomposition along the theta axis is also a function of aNphi.

Parameters

aNphi the number of slices in the longitude polar coordinates.

◆ ~SphericalAccumulator()

template<typename TVector >

DGtal::SphericalAccumulator< TVector >::~SphericalAccumulator ( )

Destructor.

◆ SphericalAccumulator() [2/3]

template<typename TVector >

DGtal::SphericalAccumulator< TVector >::SphericalAccumulator ( const SphericalAccumulator< TVector > & other )

inline

Copy constructor.

Parameters

other the object to clone.

Definition at line 338 of file SphericalAccumulator.h.

    {
      myNphi = other.myNphi;
      myNtheta = other.myNtheta;
      myAccumulator = other.myAccumulator;
      myAccumulatorDir = other.myAccumulatorDir;
      myTotal = other.myTotal;
      myBinNumber = other.myBinNumber;
      myMaxBinPhi = other.myMaxBinPhi;
      myMaxBinTheta = other.myMaxBinTheta;
    }

References DGtal::SphericalAccumulator< TVector >::myAccumulator, DGtal::SphericalAccumulator< TVector >::myAccumulatorDir, DGtal::SphericalAccumulator< TVector >::myBinNumber, DGtal::SphericalAccumulator< TVector >::myMaxBinPhi, DGtal::SphericalAccumulator< TVector >::myMaxBinTheta, DGtal::SphericalAccumulator< TVector >::myNphi, DGtal::SphericalAccumulator< TVector >::myNtheta, and DGtal::SphericalAccumulator< TVector >::myTotal.

◆ SphericalAccumulator() [3/3]

template<typename TVector >

DGtal::SphericalAccumulator< TVector >::SphericalAccumulator ( )

protected

Constructor. Forbidden by default (protected to avoid g++ warnings).

Member Function Documentation

◆ addDirection()

template<typename TVector >

void DGtal::SphericalAccumulator< TVector >::addDirection ( const Vector & aDir )

Add a new direction into the accumulator. The accumulator updates the bin coordinates with maximum count.

Parameters

aDir	a direction

Referenced by testSphericalAccumulator(), testSphericalMore(), and testSphericalMoreIntegerDir().

◆ begin()

template<typename TVector >

ConstIterator DGtal::SphericalAccumulator< TVector >::begin ( ) const

inline

Warning: Be careful, some of the iterators may be attached to un-valid bins. Once you have the iterator, convert it to bin coordinates using binCoordinates and then check if the bin is valid using isValidBin method.

Returns: an iterator on the bin value container (begin).

Definition at line 308 of file SphericalAccumulator.h.

    {
      return myAccumulator.begin();
    }

References DGtal::SphericalAccumulator< TVector >::myAccumulator.

Referenced by testSphericalAccumulator(), testSphericalMore(), and testSphericalMoreIntegerDir().

◆ binCoordinates() [1/2]

template<typename TVector >

void DGtal::SphericalAccumulator< TVector >::binCoordinates	(	const Vector &	aDir,
		Size &	posPhi,
		Size &	posTheta ) const

Given a normalized direction, this method computes the bin coordinates.

Precondition: aDir a direction.

Parameters

aDir	a direction represented as a unit norm vector.
posPhi	position according to the first direction.
posTheta	position according to the second direction.

Referenced by testSphericalAccumulator().

◆ binCoordinates() [2/2]

template<typename TVector >

void DGtal::SphericalAccumulator< TVector >::binCoordinates	(	ConstIterator &	aDir,
		Size &	posPhi,
		Size &	posTheta ) const

Given an iterator on the bin container, this method computes the bin coordinates.

Parameters

aDir	an iterator to the bin container.
posPhi	position according to the first direction.
posTheta	position according to the second direction.

◆ binNumber()

template<typename TVector >

Quantity DGtal::SphericalAccumulator< TVector >::binNumber ( ) const

inline

Returns: returns the number of bins in the accumulator.

Definition at line 217 of file SphericalAccumulator.h.

217{ return myBinNumber;}

References DGtal::SphericalAccumulator< TVector >::myBinNumber.

◆ BOOST_STATIC_ASSERT()

template<typename TVector >

DGtal::SphericalAccumulator< TVector >::BOOST_STATIC_ASSERT ( Vector::dimension = =3 )

◆ className()

template<typename TVector >

std::string DGtal::SphericalAccumulator< TVector >::className ( ) const

inline

Returns: the class name.

Definition at line 252 of file SphericalAccumulator.h.

    {
      return "SphericalAccumulator";
    }

◆ clear()

template<typename TVector >

void DGtal::SphericalAccumulator< TVector >::clear ( )

Clear the current accumulator.

Referenced by testSphericalAccumulator().

◆ count()

template<typename TVector >

Quantity DGtal::SphericalAccumulator< TVector >::count	(	const Size &	posPhi,
		const Size &	posTheta ) const

Returns the current number of samples in the bin (posPhi,posTheta).

Parameters

posPhi	position according to the first direction
posTheta	position according to the second direction

Returns: the number of accumulated samples

Referenced by testSphericalAccumulator().

◆ end()

template<typename TVector >

ConstIterator DGtal::SphericalAccumulator< TVector >::end ( ) const

inline

Returns: an iterator on the bin value container (end).

Definition at line 316 of file SphericalAccumulator.h.

    {
      return myAccumulator.end();
    }

References DGtal::SphericalAccumulator< TVector >::myAccumulator.

Referenced by testSphericalAccumulator(), testSphericalMore(), and testSphericalMoreIntegerDir().

◆ getBinDirection()

template<typename TVector >

RealVector DGtal::SphericalAccumulator< TVector >::getBinDirection	(	const Size &	posPhi,
		const Size &	posTheta ) const

From the bin index(posPhi,posTheta), we compute the main direction (quad geometry midpoint).

Parameters

posPhi	bin index along the first direction.
posTheta	bin index along the second direction.

Returns: the main direction of a bin (quand mid-point).

◆ getBinGeometry()

template<typename TVector >

void DGtal::SphericalAccumulator< TVector >::getBinGeometry	(	const Size &	posPhi,
		const Size &	posTheta,
		RealVector &	a,
		RealVector &	b,
		RealVector &	c,
		RealVector &	d ) const

From the bin index(posPhi,posTheta), we compute the associated spherical quad (a,b,c,d) counterclockwise on the unit sphere.

Parameters

posPhi	bin index along the first direction.
posTheta	bin index along the second direction.
a	vertex position.
b	vertex position.
c	vertex position.
d	vertex position.

◆ isValid()

template<typename TVector >

bool DGtal::SphericalAccumulator< TVector >::isValid ( ) const

Checks the validity/consistency of the object.

Returns: 'true' if the object is valid, 'false' otherwise.

◆ isValidBin()

template<typename TVector >

bool DGtal::SphericalAccumulator< TVector >::isValidBin	(	const Size &	posPhi,
		const Size &	posTheta ) const

Returns true if is bin (posPhi,posTheta) is valid.

Parameters

posPhi	posPhi index
posTheta	posTheta index

Returns: true if (posPhi,posTheta) is valid.

◆ maxCountBin()

template<typename TVector >

void DGtal::SphericalAccumulator< TVector >::maxCountBin	(	Size &	posPhi,
		Size &	posTheta ) const

Returns the coordinates of the bin containing the maximum number of samples.

Parameters

posPhi	coordinate along the phi axis.
posTheta	coordinate along the theta axis.

Referenced by testSphericalMoreIntegerDir().

◆ operator=()

template<typename TVector >

SphericalAccumulator & DGtal::SphericalAccumulator< TVector >::operator= ( const SphericalAccumulator< TVector > & other )

inline

Assignment.

Parameters

other the object to copy.

Returns: a reference on 'this'. Forbidden by default.

Definition at line 356 of file SphericalAccumulator.h.

    {
      if (this!=other)
      {
        myNphi = other.myNphi;
        myNtheta = other.myNtheta;
        myAccumulator = other.myAccumulator;
        myAccumulatorDir = other.myAccumulatorDir;
        myTotal = other.myTotal;
        myBinNumber = other.myBinNumber;
        myMaxBinPhi = other.myMaxBinPhi;
        myMaxBinTheta = other.myMaxBinTheta; 
      }
      return *this;
    }

References DGtal::SphericalAccumulator< TVector >::myAccumulator, DGtal::SphericalAccumulator< TVector >::myAccumulatorDir, DGtal::SphericalAccumulator< TVector >::myBinNumber, DGtal::SphericalAccumulator< TVector >::myMaxBinPhi, DGtal::SphericalAccumulator< TVector >::myMaxBinTheta, DGtal::SphericalAccumulator< TVector >::myNphi, DGtal::SphericalAccumulator< TVector >::myNtheta, and DGtal::SphericalAccumulator< TVector >::myTotal.

◆ representativeDirection() [1/2]

template<typename TVector >

Vector DGtal::SphericalAccumulator< TVector >::representativeDirection	(	const Size &	posPhi,
		const Size &	posTheta ) const

Returns the representative direction associated with the bin (posPhi,posTheta). If the bin does not contain any sample, a null vector is returned ( Vector::ZERO ).

Otherwise, it returns the (unnormalized) sum of directions added to the bin.

Parameters

posPhi	position according to the first direction
posTheta	position according to the second direction

Returns: the representative direction.

Referenced by testSphericalAccumulator(), and testSphericalMoreIntegerDir().

◆ representativeDirection() [2/2]

template<typename TVector >

Vector DGtal::SphericalAccumulator< TVector >::representativeDirection ( ConstIterator & it ) const

Get the representative direction of a bin specified by a ConstIterator.

Parameters

it	the iterator on the bin to get the direction

Returns: the representative direction of bin it.

◆ samples()

template<typename TVector >

Quantity DGtal::SphericalAccumulator< TVector >::samples ( ) const

Returns: returns the number of directions in the current accumulator.

Referenced by testSphericalAccumulator().

◆ selfDisplay()

template<typename TVector >

void DGtal::SphericalAccumulator< TVector >::selfDisplay ( std::ostream & out ) const

Writes/Displays the object on an output stream.

Parameters

out	the output stream where the object is written.

Field Documentation

◆ myAccumulator

template<typename TVector >

std::vector<Quantity> DGtal::SphericalAccumulator< TVector >::myAccumulator

private

Accumulator container.

Definition at line 384 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::begin(), DGtal::SphericalAccumulator< TVector >::end(), DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

◆ myAccumulatorDir

template<typename TVector >

std::vector<Vector> DGtal::SphericalAccumulator< TVector >::myAccumulatorDir

private

Accumulator reprensentative directions.

Definition at line 387 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

◆ myBinNumber

template<typename TVector >

Quantity DGtal::SphericalAccumulator< TVector >::myBinNumber

private

Number of bins.

Definition at line 393 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::binNumber(), DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

◆ myMaxBinPhi

template<typename TVector >

Size DGtal::SphericalAccumulator< TVector >::myMaxBinPhi

private

Phi coordinate of the max bin.

Definition at line 396 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

◆ myMaxBinTheta

template<typename TVector >

Size DGtal::SphericalAccumulator< TVector >::myMaxBinTheta

private

Theta coordinate of the max bin.

Definition at line 399 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

◆ myNphi

template<typename TVector >

Size DGtal::SphericalAccumulator< TVector >::myNphi

private

Number of slices in the phi direction.

Definition at line 378 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

◆ myNtheta

template<typename TVector >

Size DGtal::SphericalAccumulator< TVector >::myNtheta

private

Number of bins in the theta direction.

Definition at line 381 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

◆ myTotal

template<typename TVector >

Quantity DGtal::SphericalAccumulator< TVector >::myTotal

private

Number of samples.

Definition at line 390 of file SphericalAccumulator.h.

Referenced by DGtal::SphericalAccumulator< TVector >::operator=(), and DGtal::SphericalAccumulator< TVector >::SphericalAccumulator().

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

SphericalAccumulator.h

Public Types

Public Member Functions

Protected Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ ConstIterator

◆ Quantity

◆ RealVector

◆ Size

◆ Vector

Constructor & Destructor Documentation

◆ SphericalAccumulator() [1/3]

◆ ~SphericalAccumulator()

◆ SphericalAccumulator() [2/3]

◆ SphericalAccumulator() [3/3]

Member Function Documentation

◆ addDirection()

◆ begin()

◆ binCoordinates() [1/2]

◆ binCoordinates() [2/2]

◆ binNumber()

◆ BOOST_STATIC_ASSERT()

◆ className()

◆ clear()

◆ count()

◆ end()

◆ getBinDirection()

◆ getBinGeometry()

◆ isValid()

◆ isValidBin()

◆ maxCountBin()

◆ operator=()

◆ representativeDirection() [1/2]

◆ representativeDirection() [2/2]

◆ samples()

◆ selfDisplay()

Field Documentation

◆ myAccumulator

◆ myAccumulatorDir

◆ myBinNumber

◆ myMaxBinPhi

◆ myMaxBinTheta

◆ myNphi

◆ myNtheta

◆ myTotal