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ITK
4.13.0
Insight Segmentation and Registration Toolkit
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#include <itkGaussianOperator.h>
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 a Neighborhood (NeighborhoodIterator) 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.).
Definition at line 67 of file itkGaussianOperator.h.
Public Types | |
typedef GaussianOperator | Self |
typedef NeighborhoodOperator < TPixel, VDimension, TAllocator > | Superclass |
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typedef NumericTraits< TPixel > ::RealType | PixelRealType |
typedef TPixel | PixelType |
typedef NeighborhoodOperator | Self |
typedef Superclass::SizeType | SizeType |
typedef SliceIterator< TPixel, Self > | SliceIteratorType |
typedef Neighborhood< TPixel, VDimension, TAllocator > | Superclass |
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typedef TAllocator | AllocatorType |
typedef AllocatorType::const_iterator | ConstIterator |
typedef unsigned int | DimensionValueType |
typedef AllocatorType::iterator | Iterator |
typedef SizeValueType | NeighborIndexType |
typedef Offset< VDimension > | OffsetType |
typedef TPixel | PixelType |
typedef Neighborhood | Self |
typedef SizeType::SizeValueType | SizeValueType |
typedef SliceIterator< TPixel, Self > | SliceIteratorType |
Protected Types | |
typedef Superclass::CoefficientVector | CoefficientVector |
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typedef std::vector < PixelRealType > | CoefficientVector |
Protected Member Functions | |
void | Fill (const CoefficientVector &coeff) override |
CoefficientVector | GenerateCoefficients () override |
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virtual void | FillCenteredDirectional (const CoefficientVector &) |
void | InitializeToZero () |
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virtual void | Allocate (NeighborIndexType i) |
virtual void | ComputeNeighborhoodOffsetTable () |
virtual void | ComputeNeighborhoodStrideTable () |
void | SetSize () |
Private Attributes | |
double | m_MaximumError |
unsigned int | m_MaximumKernelWidth |
double | m_Variance |
Additional Inherited Members | |
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typedef::itk::Size< VDimension > | RadiusType |
typedef::itk::Size< VDimension > | SizeType |
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static const unsigned int | NeighborhoodDimension = VDimension |
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protected |
Definition at line 159 of file itkGaussianOperator.h.
typedef GaussianOperator itk::GaussianOperator< TPixel, VDimension, TAllocator >::Self |
Standard class typedefs.
Definition at line 73 of file itkGaussianOperator.h.
typedef NeighborhoodOperator< TPixel, VDimension, TAllocator > itk::GaussianOperator< TPixel, VDimension, TAllocator >::Superclass |
Definition at line 74 of file itkGaussianOperator.h.
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inline |
Constructor.
Definition at line 79 of file itkGaussianOperator.h.
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inline |
Copy constructor
Definition at line 82 of file itkGaussianOperator.h.
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inlineoverrideprotectedvirtual |
Arranges coefficients spatially in the memory buffer.
Implements itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.
Definition at line 179 of file itkGaussianOperator.h.
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overrideprotectedvirtual |
Calculates operator coefficients.
Implements itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.
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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 133 of file itkGaussianOperator.h.
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Returns the maximum allowed kernel width.
Definition at line 144 of file itkGaussianOperator.h.
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virtual |
Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.
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Returns the variance of the Gaussian (scale) for the operator.
Definition at line 126 of file itkGaussianOperator.h.
double itk::GaussianOperator< TPixel, VDimension, TAllocator >::ModifiedBesselI | ( | int | , |
double | |||
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Returns the value of the modified Bessel function Ik(x) at a point x>=0, where k>=2.
double itk::GaussianOperator< TPixel, VDimension, TAllocator >::ModifiedBesselI0 | ( | double | ) |
Returns the value of the modified Bessel function I0(x) at a point x >= 0.
double itk::GaussianOperator< TPixel, VDimension, TAllocator >::ModifiedBesselI1 | ( | double | ) |
Returns the value of the modified Bessel function I1(x) at a point x, x real.
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Assignment operator
Definition at line 92 of file itkGaussianOperator.h.
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inlineoverridevirtual |
Prints some debugging information.
Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.
Definition at line 148 of file itkGaussianOperator.h.
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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. The value must be between 0.0 and 1.0.
Definition at line 115 of file itkGaussianOperator.h.
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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 140 of file itkGaussianOperator.h.
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Sets the desired variance of the Gaussian kernel.
Definition at line 106 of file itkGaussianOperator.h.
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Difference between the areas under the curves of the continuous and discrete Gaussian functions.
Definition at line 188 of file itkGaussianOperator.h.
Referenced by itk::GaussianOperator< ScalarType, Superclass::Dimension >::GaussianOperator(), and itk::GaussianOperator< ScalarType, Superclass::Dimension >::operator=().
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Maximum kernel size allowed. This value is used to truncate a kernel that has grown too large. A warning is given when the specified maximum error causes the kernel to exceed this size.
Definition at line 193 of file itkGaussianOperator.h.
Referenced by itk::GaussianOperator< ScalarType, Superclass::Dimension >::GaussianOperator(), and itk::GaussianOperator< ScalarType, Superclass::Dimension >::operator=().
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private |
Desired variance of the discrete Gaussian function.
Definition at line 184 of file itkGaussianOperator.h.
Referenced by itk::GaussianOperator< ScalarType, Superclass::Dimension >::GaussianOperator(), and itk::GaussianOperator< ScalarType, Superclass::Dimension >::operator=().