itk::simple::CannyEdgeDetectionImageFilter Class Reference

This filter is an implementation of a Canny edge detector for scalar-valued images. More...

#include <sitkCannyEdgeDetectionImageFilter.h>

Inheritance diagram for itk::simple::CannyEdgeDetectionImageFilter:

Collaboration diagram for itk::simple::CannyEdgeDetectionImageFilter:

Detailed Description

This filter is an implementation of a Canny edge detector for scalar-valued images.

Based on John Canny's paper "A Computational Approach to Edge Detection"(IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. PAMI-8, No.6, November 1986), there are four major steps used in the edge-detection scheme: (1) Smooth the input image with Gaussian filter. (2) Calculate the second directional derivatives of the smoothed image. (3) Non-Maximum Suppression: the zero-crossings of 2nd derivative are found, and the sign of third derivative is used to find the correct extrema. (4) The hysteresis thresholding is applied to the gradient magnitude (multiplied with zero-crossings) of the smoothed image to find and link edges.

Inputs and Outputs

The input to this filter should be a scalar, real-valued Itk image of arbitrary dimension. The output should also be a scalar, real-value Itk image of the same dimensionality.

Parameters

There are four parameters for this filter that control the sub-filters used by the algorithm.

Variance and Maximum error are used in the Gaussian smoothing of the input image. See itkDiscreteGaussianImageFilter for information on these parameters.

Threshold is the lowest allowed value in the output image. Its data type is the same as the data type of the output image. Any values below the Threshold level will be replaced with the OutsideValue parameter value, whose default is zero.

TodoEdge-linking will be added when an itk connected component labeling algorithm is available.

See also

DiscreteGaussianImageFilter

ZeroCrossingImageFilter

ThresholdImageFilter

itk::simple::CannyEdgeDetection for the procedural interface

itk::CannyEdgeDetectionImageFilter for the Doxygen on the original ITK class.

Definition at line 70 of file sitkCannyEdgeDetectionImageFilter.h.

Public Types
using	PixelIDTypeList = RealPixelIDTypeList
using	Self = CannyEdgeDetectionImageFilter
Public Types inherited from itk::simple::ImageFilter
using	Self = ImageFilter
Public Types inherited from itk::simple::ProcessObject
using	Self = ProcessObject

Public Member Functions
	CannyEdgeDetectionImageFilter ()
Image	Execute (const Image &image1)
double	GetLowerThreshold () const
std::vector< double >	GetMaximumError () const
std::string	GetName () const
double	GetUpperThreshold () const
std::vector< double >	GetVariance () const
Self &	SetLowerThreshold (double LowerThreshold)
	Set the lower threshold value for detected edges. More...
Self &	SetMaximumError (double value)
Self &	SetMaximumError (std::vector< double > MaximumError)
Self &	SetUpperThreshold (double UpperThreshold)
	Set the upper threshold value for detected edges. More...
Self &	SetVariance (double value)
Self &	SetVariance (std::vector< double > Variance)
std::string	ToString () const
virtual	~CannyEdgeDetectionImageFilter ()
Public Member Functions inherited from itk::simple::ImageFilter
	ImageFilter ()
virtual	~ImageFilter ()=0
Public Member Functions inherited from itk::simple::ProcessObject
virtual void	Abort ()
virtual int	AddCommand (itk::simple::EventEnum event, const std::function< void()> &func)
	Directly add a callback to observe an event. More...
virtual int	AddCommand (itk::simple::EventEnum event, itk::simple::Command &cmd)
	Add a Command Object to observer the event. More...
virtual float	GetProgress () const
	An Active Measurement of the progress of execution. More...
virtual bool	HasCommand (itk::simple::EventEnum event) const
	Query of this object has any registered commands for event. More...
	ProcessObject ()
virtual void	RemoveAllCommands ()
	Remove all registered commands. More...
virtual	~ProcessObject ()
virtual void	DebugOn ()
virtual void	DebugOff ()
virtual bool	GetDebug () const
virtual void	SetDebug (bool debugFlag)
virtual void	SetNumberOfThreads (unsigned int n)
virtual unsigned int	GetNumberOfThreads () const
virtual void	SetNumberOfWorkUnits (unsigned int n)
virtual unsigned int	GetNumberOfWorkUnits () const

Private Types
using	MemberFunctionType = Image(Self::*)(const Image &image1)

Private Member Functions
template<class TImageType >
Image	ExecuteInternal (const Image &image1)

Private Attributes
double	m_LowerThreshold {0.0}
std::vector< double >	m_MaximumError {std::vector<double>(3, 0.01)}
std::unique_ptr< detail::MemberFunctionFactory< MemberFunctionType > >	m_MemberFactory
double	m_UpperThreshold {0.0}
std::vector< double >	m_Variance {std::vector<double>(3, 0.0)}

Friends
struct	detail::MemberFunctionAddressor< MemberFunctionType >

Additional Inherited Members
Static Public Member Functions inherited from itk::simple::ProcessObject
static bool	GetGlobalDefaultDebug ()
static void	GlobalDefaultDebugOff ()
static void	GlobalDefaultDebugOn ()
static void	SetGlobalDefaultDebug (bool debugFlag)
static void	GlobalWarningDisplayOn ()
static void	GlobalWarningDisplayOff ()
static void	SetGlobalWarningDisplay (bool flag)
static bool	GetGlobalWarningDisplay ()
static double	GetGlobalDefaultCoordinateTolerance ()
	Access the global tolerance to determine congruent spaces. More...
static void	SetGlobalDefaultCoordinateTolerance (double)
	Access the global tolerance to determine congruent spaces. More...
static double	GetGlobalDefaultDirectionTolerance ()
	Access the global tolerance to determine congruent spaces. More...
static void	SetGlobalDefaultDirectionTolerance (double)
	Access the global tolerance to determine congruent spaces. More...
static bool	SetGlobalDefaultThreader (const std::string &threader)
	Set/Get the default threader used for process objects. More...
static std::string	GetGlobalDefaultThreader ()
	Set/Get the default threader used for process objects. More...
static void	SetGlobalDefaultNumberOfThreads (unsigned int n)
static unsigned int	GetGlobalDefaultNumberOfThreads ()
	Set/Get the default threader used for process objects. More...
Protected Member Functions inherited from itk::simple::ImageFilter
void	CheckImageMatchingDimension (const Image &image1, const Image &image2, const std::string &image2Name)
void	CheckImageMatchingPixelType (const Image &image1, const Image &image2, const std::string &image2Name)
void	CheckImageMatchingSize (const Image &image1, const Image &image2, const std::string &image2Name)
Protected Member Functions inherited from itk::simple::ProcessObject
virtual unsigned long	AddITKObserver (const itk::EventObject &, itk::Command *)
virtual itk::ProcessObject *	GetActiveProcess ()
virtual void	OnActiveProcessDelete ()
virtual void	onCommandDelete (const itk::simple::Command *cmd) noexcept
virtual void	PreUpdate (itk::ProcessObject *p)
virtual void	RemoveITKObserver (EventCommand &e)
Protected Member Functions inherited from itk::simple::NonCopyable
	NonCopyable ()=default
	NonCopyable (const NonCopyable &)=delete
NonCopyable &	operator= (const NonCopyable &)=delete
Static Protected Member Functions inherited from itk::simple::ImageFilter
template<class TImageType >
static void	FixNonZeroIndex (TImageType *img)
Static Protected Member Functions inherited from itk::simple::ProcessObject
template<class TImageType >
static TImageType::ConstPointer	CastImageToITK (const Image &img)
template<class TPixelType , unsigned int VImageDimension, unsigned int VLength, template< typename, unsigned int > class TVector>
static Image	CastITKToImage (itk::Image< TVector< TPixelType, VLength >, VImageDimension > *img)
template<unsigned int VImageDimension, unsigned int VLength, template< unsigned int > class TVector>
static Image	CastITKToImage (itk::Image< TVector< VLength >, VImageDimension > *img)
template<class TImageType >
static Image	CastITKToImage (TImageType *img)
static const itk::EventObject &	GetITKEventObject (EventEnum e)
template<typename T >
static std::ostream &	ToStringHelper (std::ostream &os, const T &v)
static std::ostream &	ToStringHelper (std::ostream &os, const char &v)
static std::ostream &	ToStringHelper (std::ostream &os, const signed char &v)
static std::ostream &	ToStringHelper (std::ostream &os, const unsigned char &v)

Member Typedef Documentation

MemberFunctionType

using itk::simple::CannyEdgeDetectionImageFilter::MemberFunctionType = Image (Self::*)( const Image& image1 )

private

Setup for member function dispatching

Definition at line 144 of file sitkCannyEdgeDetectionImageFilter.h.

PixelIDTypeList

using itk::simple::CannyEdgeDetectionImageFilter::PixelIDTypeList = RealPixelIDTypeList

Define the pixels types supported by this filter

Definition at line 82 of file sitkCannyEdgeDetectionImageFilter.h.

Self

using itk::simple::CannyEdgeDetectionImageFilter::Self = CannyEdgeDetectionImageFilter

Definition at line 72 of file sitkCannyEdgeDetectionImageFilter.h.

Constructor & Destructor Documentation

~CannyEdgeDetectionImageFilter()

virtual itk::simple::CannyEdgeDetectionImageFilter::~CannyEdgeDetectionImageFilter ( )

virtual

Destructor

CannyEdgeDetectionImageFilter()

itk::simple::CannyEdgeDetectionImageFilter::CannyEdgeDetectionImageFilter

(

)

Default Constructor that takes no arguments and initializes default parameters

Member Function Documentation

Execute()

Image itk::simple::CannyEdgeDetectionImageFilter::Execute

(

const Image &

image1

)

Execute the filter on the input image

ExecuteInternal()

template<class TImageType >

Image itk::simple::CannyEdgeDetectionImageFilter::ExecuteInternal ( const Image &  image1 )

private

GetLowerThreshold()

double itk::simple::CannyEdgeDetectionImageFilter::GetLowerThreshold ( ) const

inline

Definition at line 92 of file sitkCannyEdgeDetectionImageFilter.h.

GetMaximumError()

std::vector<double> itk::simple::CannyEdgeDetectionImageFilter::GetMaximumError ( ) const

inline

Set/Get the maximum error of the Gaussian smoothing kernel in each dimensional direction.

Definition at line 127 of file sitkCannyEdgeDetectionImageFilter.h.

GetName()

std::string itk::simple::CannyEdgeDetectionImageFilter::GetName ( ) const

inlinevirtual

Name of this class

Implements itk::simple::ProcessObject.

Definition at line 130 of file sitkCannyEdgeDetectionImageFilter.h.

GetUpperThreshold()

double itk::simple::CannyEdgeDetectionImageFilter::GetUpperThreshold ( ) const

inline

Definition at line 101 of file sitkCannyEdgeDetectionImageFilter.h.

GetVariance()

std::vector<double> itk::simple::CannyEdgeDetectionImageFilter::GetVariance ( ) const

inline

Set/Get the variance of the Gaussian smoothing filter.

Definition at line 114 of file sitkCannyEdgeDetectionImageFilter.h.

SetLowerThreshold()

Self& itk::simple::CannyEdgeDetectionImageFilter::SetLowerThreshold ( double  LowerThreshold )

inline

Set the lower threshold value for detected edges.

Definition at line 88 of file sitkCannyEdgeDetectionImageFilter.h.

SetMaximumError() [1/2]

Self& itk::simple::CannyEdgeDetectionImageFilter::SetMaximumError ( double  value )

inline

Set the values of the MaximumError vector all to value

Definition at line 122 of file sitkCannyEdgeDetectionImageFilter.h.

SetMaximumError() [2/2]

Self& itk::simple::CannyEdgeDetectionImageFilter::SetMaximumError ( std::vector< double >  MaximumError )

inline

Set/Get the MaximumError parameter used by the Gaussian smoothing filter in this algorithm

Definition at line 119 of file sitkCannyEdgeDetectionImageFilter.h.

SetUpperThreshold()

Self& itk::simple::CannyEdgeDetectionImageFilter::SetUpperThreshold ( double  UpperThreshold )

inline

Set the upper threshold value for detected edges.

Definition at line 97 of file sitkCannyEdgeDetectionImageFilter.h.

SetVariance() [1/2]

Self& itk::simple::CannyEdgeDetectionImageFilter::SetVariance ( double  value )

inline

Set the values of the Variance vector all to value

Definition at line 109 of file sitkCannyEdgeDetectionImageFilter.h.

SetVariance() [2/2]

Self& itk::simple::CannyEdgeDetectionImageFilter::SetVariance ( std::vector< double >  Variance )

inline

Set/Get the variance of the Gaussian smoothing filter.

Definition at line 106 of file sitkCannyEdgeDetectionImageFilter.h.

ToString()

std::string itk::simple::CannyEdgeDetectionImageFilter::ToString ( ) const

virtual

Print ourselves out

Reimplemented from itk::simple::ProcessObject.

Friends And Related Function Documentation

detail::MemberFunctionAddressor< MemberFunctionType >

friend struct detail::MemberFunctionAddressor< MemberFunctionType >

friend

Definition at line 148 of file sitkCannyEdgeDetectionImageFilter.h.

Member Data Documentation

m_LowerThreshold

double itk::simple::CannyEdgeDetectionImageFilter::m_LowerThreshold {0.0}

private

Definition at line 153 of file sitkCannyEdgeDetectionImageFilter.h.

m_MaximumError

std::vector<double> itk::simple::CannyEdgeDetectionImageFilter::m_MaximumError {std::vector<double>(3, 0.01)}

private

Definition at line 161 of file sitkCannyEdgeDetectionImageFilter.h.

m_MemberFactory

std::unique_ptr<detail::MemberFunctionFactory<MemberFunctionType> > itk::simple::CannyEdgeDetectionImageFilter::m_MemberFactory

private

Definition at line 150 of file sitkCannyEdgeDetectionImageFilter.h.

m_UpperThreshold

double itk::simple::CannyEdgeDetectionImageFilter::m_UpperThreshold {0.0}

private

Definition at line 155 of file sitkCannyEdgeDetectionImageFilter.h.

m_Variance

std::vector<double> itk::simple::CannyEdgeDetectionImageFilter::m_Variance {std::vector<double>(3, 0.0)}

private

Definition at line 158 of file sitkCannyEdgeDetectionImageFilter.h.

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

• sitkCannyEdgeDetectionImageFilter.h