itk::GaussianOperator< TPixel, VDimension, TAllocator > Class Template Reference
[Operators]

A NeighborhoodOperator whose coefficients are a one dimensional, discrete Gaussian kernel. More...

#include <itkGaussianOperator.h>

Inheritance diagram for itk::GaussianOperator< TPixel, VDimension, TAllocator >:

[legend]Collaboration diagram for itk::GaussianOperator< TPixel, VDimension, TAllocator >:

[legend]List of all members.

Public Types
typedef GaussianOperator	Self
typedef NeighborhoodOperator< TPixel, VDimension, TAllocator >	Superclass
Public Member Functions
	GaussianOperator ()
void	SetVariance (const double &variance)
void	SetMaximumError (const double &max_error)
double	GetVariance ()
double	GetMaximumError ()
void	SetMaximumKernelWidth (unsigned int n)
unsigned int	GetMaximumKernelWidth () const
	GaussianOperator (const Self &other)
Self &	operator= (const Self &other)
virtual void	PrintSelf (std::ostream &os, Indent i) const
Protected Types
typedef Superclass::CoefficientVector	CoefficientVector
Protected Member Functions
double	ModifiedBesselI0 (double)
double	ModifiedBesselI1 (double)
double	ModifiedBesselI (int, double)
CoefficientVector	GenerateCoefficients ()
void	Fill (const CoefficientVector &coeff)

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Detailed Description

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>>
class itk::GaussianOperator< TPixel, VDimension, TAllocator >

A NeighborhoodOperator whose coefficients are a one dimensional, discrete Gaussian kernel.

GaussianOperator can be used to perform Gaussian blurring by taking its inner product with to a Neighborhood (NeighborhooIterator) that is swept across an image region. It is a directional operator. N successive applications oriented along each dimensional direction will effect separable, efficient, N-D Gaussian blurring of an image region.

GaussianOperator takes two parameters:

(1) The floating-point variance of the desired Gaussian function.

(2) The "maximum error" allowed in the discrete Gaussian function. "Maximum errror" is defined as the difference between the area under the discrete Gaussian curve and the area under the continuous Gaussian. Maximum error affects the Gaussian operator size. Care should be taken not to make this value too small relative to the variance lest the operator size become unreasonably large.

References: The Gaussian kernel contained in this operator was described by Tony Lindeberg (Discrete Scale-Space Theory and the Scale-Space Primal Sketch. Dissertation. Royal Institute of Technology, Stockholm, Sweden. May 1991.).

See also:

NeighborhoodOperator

NeighborhoodIterator

Neighborhood

Definition at line 61 of file itkGaussianOperator.h.

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Member Typedef Documentation

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> typedef Superclass::CoefficientVector itk::GaussianOperator< TPixel, VDimension, TAllocator >::CoefficientVector [protected]

Typedef support for coefficient vector type. Necessary to fix bug in the microsoft VC++ compiler. Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >. Definition at line 145 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> typedef GaussianOperator itk::GaussianOperator< TPixel, VDimension, TAllocator >::Self

Standard class typedefs. Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >. Definition at line 66 of file itkGaussianOperator.h. Referenced by itk::GaussianOperator< TPixel, VDimension, TAllocator >::GaussianOperator().

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> typedef NeighborhoodOperator<TPixel, VDimension, TAllocator> itk::GaussianOperator< TPixel, VDimension, TAllocator >::Superclass

Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >. Definition at line 67 of file itkGaussianOperator.h.

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Constructor & Destructor Documentation

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> itk::GaussianOperator< TPixel, VDimension, TAllocator >::GaussianOperator (   )  [inline]

Constructor. Definition at line 70 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> itk::GaussianOperator< TPixel, VDimension, TAllocator >::GaussianOperator (  const Self &  other  )  [inline]

Copy constructor Definition at line 73 of file itkGaussianOperator.h. References itk::GaussianOperator< TPixel, VDimension, TAllocator >::Self.

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Member Function Documentation

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> void itk::GaussianOperator< TPixel, VDimension, TAllocator >::Fill (  const CoefficientVector &  coeff  )  [inline, protected, virtual]

Arranges coefficients spatially in the memory buffer. Implements itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >. Definition at line 162 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> CoefficientVector itk::GaussianOperator< TPixel, VDimension, TAllocator >::GenerateCoefficients (   )  [protected, virtual]

Calculates operator coefficients. Implements itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> double itk::GaussianOperator< TPixel, VDimension, TAllocator >::GetMaximumError (   )  [inline]

Returns the maximum error of the gaussian approximation. Maximum error is the difference between the area under the discrete Gaussian curve and the area under the continuous Gaussian. Maximum error affects the Gaussian operator size. Definition at line 119 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> unsigned int itk::GaussianOperator< TPixel, VDimension, TAllocator >::GetMaximumKernelWidth (   )  const [inline]

Returns the maximum allowed kernel width. Definition at line 130 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> double itk::GaussianOperator< TPixel, VDimension, TAllocator >::GetVariance (  void   )  [inline]

Returns the variance of the Gaussian (scale) for the operator. Definition at line 112 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> double itk::GaussianOperator< TPixel, VDimension, TAllocator >::ModifiedBesselI (  int  , double  )  [protected]

Returns the value of the modified Bessel function Ik(x) at a point x>=0, where k>=2.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> double itk::GaussianOperator< TPixel, VDimension, TAllocator >::ModifiedBesselI0 (  double   )  [protected]

Returns the value of the modified Bessel function I0(x) at a point x >= 0.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> double itk::GaussianOperator< TPixel, VDimension, TAllocator >::ModifiedBesselI1 (  double   )  [protected]

Returns the value of the modified Bessel function I1(x) at a point x, x real.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> Self& itk::GaussianOperator< TPixel, VDimension, TAllocator >::operator= (  const Self &  other  )  [inline]

Assignment operator Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >. Definition at line 83 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> virtual void itk::GaussianOperator< TPixel, VDimension, TAllocator >::PrintSelf (  std::ostream &  os, Indent  i )  const [inline, virtual]

Prints some debugging information. Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >. Definition at line 134 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> void itk::GaussianOperator< TPixel, VDimension, TAllocator >::SetMaximumError (  const double &  max_error  )  [inline]

Sets the desired maximum error of the gaussian approximation. Maximum error is the difference between the area under the discrete Gaussian curve and the area under the continuous Gaussian. Maximum error affects the Gaussian operator size. Definition at line 101 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> void itk::GaussianOperator< TPixel, VDimension, TAllocator >::SetMaximumKernelWidth (  unsigned int  n  )  [inline]

Sets a limit for growth of the kernel. Small maximum error values with large variances will yield very large kernel sizes. This value can be used to truncate a kernel in such instances. A warning will be given on truncation of the kernel. Definition at line 126 of file itkGaussianOperator.h.

template<class TPixel, unsigned int VDimension = 2, class TAllocator = NeighborhoodAllocator<TPixel>> void itk::GaussianOperator< TPixel, VDimension, TAllocator >::SetVariance (  const double &  variance  )  [inline]

Sets the desired variance of the Gaussian kernel. Definition at line 94 of file itkGaussianOperator.h.

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

• itkGaussianOperator.h

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