ITK  5.2.0
Insight Toolkit
Public Types | Public Member Functions | List of all members
itk::SobelOperator< TPixel, VDimension, TAllocator > Class Template Reference

#include <itkSobelOperator.h>

+ Inheritance diagram for itk::SobelOperator< TPixel, VDimension, TAllocator >:
+ Collaboration diagram for itk::SobelOperator< TPixel, VDimension, TAllocator >:

Public Types

using Self = SobelOperator
 
using Superclass = NeighborhoodOperator< TPixel, VDimension, TAllocator >
 
- Public Types inherited from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >
using PixelType = TPixel
 
using Self = NeighborhoodOperator
 
using SizeType = typename Superclass::SizeType
 
using SliceIteratorType = SliceIterator< TPixel, Self >
 
using Superclass = Neighborhood< TPixel, VDimension, TAllocator >
 
using PixelRealType = typename NumericTraits< TPixel >::RealType
 
- Public Types inherited from itk::Neighborhood< TPixel, VDimension, TAllocator >
using AllocatorType = TAllocator
 
using ConstIterator = typename AllocatorType::const_iterator
 
using DimensionValueType = unsigned int
 
using Iterator = typename AllocatorType::iterator
 
using NeighborIndexType = SizeValueType
 
using OffsetType = Offset< VDimension >
 
using PixelType = TPixel
 
using RadiusType = ::itk::Size< VDimension >
 
using Self = Neighborhood
 
using SizeType = ::itk::Size< VDimension >
 
using SizeValueType = typename SizeType::SizeValueType
 
using SliceIteratorType = SliceIterator< TPixel, Self >
 

Public Member Functions

void CreateDirectional () override
 
virtual const char * GetNameOfClass () const
 
- Public Member Functions inherited from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >
virtual void CreateToRadius (const SizeType &)
 
virtual void CreateToRadius (const SizeValueType)
 
virtual void FlipAxes ()
 
unsigned long GetDirection () const
 
void SetDirection (const unsigned long &direction)
 
void ScaleCoefficients (PixelRealType)
 
- Public Member Functions inherited from itk::Neighborhood< TPixel, VDimension, TAllocator >
 itkTypeMacroNoParent (Neighborhood)
 
 Neighborhood ()
 
virtual ~Neighborhood ()=default
 
 Neighborhood (const Self &other)
 
 Neighborhood (Self &&)=default
 
Selfoperator= (const Self &other)
 
Selfoperator= (Self &&)=default
 
bool operator== (const Self &other) const
 
bool operator!= (const Self &other) const
 
const SizeType GetRadius () const
 
SizeValueType GetRadius (DimensionValueType n) const
 
SizeValueType GetSize (DimensionValueType n) const
 
SizeType GetSize () const
 
OffsetValueType GetStride (DimensionValueType axis) const
 
Iterator End ()
 
Iterator Begin ()
 
ConstIterator End () const
 
ConstIterator Begin () const
 
NeighborIndexType Size () const
 
TPixel & operator[] (NeighborIndexType i)
 
const TPixel & operator[] (NeighborIndexType i) const
 
TPixel & GetElement (NeighborIndexType i)
 
TPixel GetCenterValue () const
 
void SetRadius (const SizeType &)
 
void SetRadius (const SizeValueType *rad)
 
void SetRadius (const SizeValueType)
 
void Print (std::ostream &os) const
 
AllocatorTypeGetBufferReference ()
 
const AllocatorTypeGetBufferReference () const
 
TPixel & operator[] (const OffsetType &o)
 
const TPixel & operator[] (const OffsetType &o) const
 
OffsetType GetOffset (NeighborIndexType i) const
 
virtual NeighborIndexType GetNeighborhoodIndex (const OffsetType &) const
 
NeighborIndexType GetCenterNeighborhoodIndex () const
 
std::slice GetSlice (unsigned int) const
 
using CoefficientVector = typename Superclass::CoefficientVector
 
using PixelType = typename Superclass::PixelType
 
void PrintSelf (std::ostream &os, Indent i) const override
 
CoefficientVector GenerateCoefficients () override
 
void Fill (const CoefficientVector &c) override
 

Additional Inherited Members

- Static Public Attributes inherited from itk::Neighborhood< TPixel, VDimension, TAllocator >
static constexpr unsigned int NeighborhoodDimension = VDimension
 
- Protected Types inherited from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >
using CoefficientVector = std::vector< PixelRealType >
 
- Protected Member Functions inherited from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >
virtual void FillCenteredDirectional (const CoefficientVector &)
 
void InitializeToZero ()
 
- Protected Member Functions inherited from itk::Neighborhood< TPixel, VDimension, TAllocator >
void SetSize ()
 
virtual void Allocate (NeighborIndexType i)
 
virtual void ComputeNeighborhoodStrideTable ()
 
virtual void ComputeNeighborhoodOffsetTable ()
 

Detailed Description

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

A NeighborhoodOperator for performing a directional Sobel edge-detection operation at a pixel location.

SobelOperator is a directional NeighborhoodOperator that should be applied a NeighborhoodIterator using the NeighborhoodInnerProduct method. To create the operator:

1) Set the direction by calling

2) call

itk::Size<2> radius;
radius.Fill(1);
sobelOperator.CreateToRadius(radius);

3) You may optionally scale the coefficients of this operator using the

method. This is useful if you want to take the spacing of the image into account when computing the edge strength. Apply the scaling only after calling to

.

The Sobel Operator in vertical direction for 2 dimensions is

*             -1  -2  -1
*             0    0   0
*             1    2   1
*
* 

The Sobel Operator in horizontal direction is for 2 dimensions is

*             -1   0   1
*             -2   0   2
*             -1   0   1
* 

The current implementation of the Sobel operator is for 2 and 3 dimensions only. The ND version is planned for future releases.

The extension to 3D is from the publication "Irwin Sobel. An Isotropic 3x3x3 Volume Gradient Operator. Technical report, Hewlett-Packard Laboratories, April 1995."

The Sobel operator in 3D has the kernel

* -1 -3 -1   0 0 0  1 3 1
* -3 -6 -3   0 0 0  3 6 3
* -1 -3 -1   0 0 0  1 3 1
*
*    x-1       x     x+1
* 

The x kernel is just rotated as required to obtain the kernel in the y and z directions.

Note
SobelOperator does not have any user-declared "special member function", following the C++ Rule of Zero: the compiler will generate them if necessary.
See also
NeighborhoodOperator
Neighborhood
ForwardDifferenceOperator
BackwardDifferenceOperator
ITK Sphinx Examples:
Examples
Examples/Iterators/NeighborhoodIterators2.cxx, Examples/Iterators/NeighborhoodIterators3.cxx, SphinxExamples/src/Core/Common/CreateSobelKernel/Code.cxx, SphinxExamples/src/Core/Common/DemonstrateAllOperators/Code.cxx, SphinxExamples/src/Filtering/ImageFilterBase/ApplyKernelToEveryPixel/Code.cxx, and SphinxExamples/src/Filtering/ImageFilterBase/ApplyKernelToEveryPixelInNonZeroImage/Code.cxx.

Definition at line 98 of file itkSobelOperator.h.

Member Typedef Documentation

◆ CoefficientVector

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
using itk::SobelOperator< TPixel, VDimension, TAllocator >::CoefficientVector = typename Superclass::CoefficientVector
protected

Typedef support for coefficient vector type. Necessary to work around compiler bug on VC++.

Definition at line 142 of file itkSobelOperator.h.

◆ PixelType

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
using itk::SobelOperator< TPixel, VDimension, TAllocator >::PixelType = typename Superclass::PixelType
protected

Typedef support for coefficient vector type. Necessary to work around compiler bug on VC++.

Definition at line 143 of file itkSobelOperator.h.

◆ Self

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
using itk::SobelOperator< TPixel, VDimension, TAllocator >::Self = SobelOperator

Standard type alias

Definition at line 103 of file itkSobelOperator.h.

◆ Superclass

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
using itk::SobelOperator< TPixel, VDimension, TAllocator >::Superclass = NeighborhoodOperator<TPixel, VDimension, TAllocator>

Definition at line 104 of file itkSobelOperator.h.

Member Function Documentation

◆ CreateDirectional()

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
void itk::SobelOperator< TPixel, VDimension, TAllocator >::CreateDirectional ( )
inlineoverridevirtual

Creates the operator with length only in the specified direction. For the Sobel operator, this The radius of the operator will be 0 except along the axis on which the operator will work.

See also
CreateToRadius
FillCenteredDirectional
SetDirection()
GetDirection()

Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.

Definition at line 114 of file itkSobelOperator.h.

◆ Fill()

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
void itk::SobelOperator< TPixel, VDimension, TAllocator >::Fill ( const CoefficientVector c)
overrideprotectedvirtual

Arranges coefficients spatially in the memory buffer.

Implements itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.

◆ GenerateCoefficients()

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
CoefficientVector itk::SobelOperator< TPixel, VDimension, TAllocator >::GenerateCoefficients ( )
overrideprotectedvirtual

Calculates operator coefficients.

Implements itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.

◆ GetNameOfClass()

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
virtual const char* itk::SobelOperator< TPixel, VDimension, TAllocator >::GetNameOfClass ( ) const
virtual

◆ PrintSelf()

template<typename TPixel, unsigned int VDimension = 2, typename TAllocator = NeighborhoodAllocator<TPixel>>
void itk::SobelOperator< TPixel, VDimension, TAllocator >::PrintSelf ( std::ostream &  os,
Indent  i 
) const
inlineoverridevirtual

Creates the operator with a specified radius ("square", same length on each side). The spatial location of the coefficients within the operator is defined by the subclass implementation of the Fill method.

See also
CreateDirectional
Fill Prints some debugging information

Reimplemented from itk::NeighborhoodOperator< TPixel, VDimension, TAllocator >.

Definition at line 130 of file itkSobelOperator.h.


The documentation for this class was generated from the following file:
itk::Size< 2 >
itk::NeighborhoodOperator::ScaleCoefficients
void ScaleCoefficients(PixelRealType)
itk::Size::Fill
void Fill(SizeValueType value)
Definition: itkSize.h:211
itk::NeighborhoodOperator::CreateToRadius
virtual void CreateToRadius(const SizeType &)
itk::NeighborhoodOperator::SetDirection
void SetDirection(const unsigned long &direction)
Definition: itkNeighborhoodOperator.h:92