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:

Public Types
typedef RealPixelIDTypeList	PixelIDTypeList

typedef CannyEdgeDetectionImageFilter	Self

Public Types inherited from itk::simple::ImageFilter< 1 >
typedef ImageFilter	Self

Public Types inherited from itk::simple::ProcessObject
typedef ProcessObject	Self

Public Member Functions
	CannyEdgeDetectionImageFilter ()

Image	Execute (const Image &image1)

Image	Execute (const Image &image1, double lowerThreshold, double upperThreshold, const std::vector< double > &variance, const std::vector< double > &maximumError)

double	GetLowerThreshold () const

std::vector< double >	GetMaximumError () const

std::string	GetName () const

double	GetUpperThreshold () const

std::vector< double >	GetVariance () const

Self &	SetLowerThreshold (double LowerThreshold)

Self &	SetMaximumError (const std::vector< double > &MaximumError)

Self &	SetMaximumError (double value)

Self &	SetUpperThreshold (double UpperThreshold)
	Set the Threshold value for detected edges. TODO: Document in the ITKv4 migration guide that the SetThreshold member function was removed from the CannyEdgeDetectionImageFilter , and that both UpperThreshold and LowerThreshold need to be set. To get the same results as with the SetThreshold method change "myfilter->SetThrehsold" to "myfilter->SetUpperThreshold", and add "myfilter->SetLowerThreshold(GetUpperThreshold()/2.0)". More...

Self &	SetVariance (const std::vector< double > &Variance)

Self &	SetVariance (double value)

std::string	ToString () const

	~CannyEdgeDetectionImageFilter ()

Public Member Functions inherited from itk::simple::ImageFilter< 1 >
	ImageFilter ()

virtual	~ImageFilter ()=0

Public Member Functions inherited from itk::simple::ProcessObject
virtual void	Abort ()

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

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

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

Private Attributes
double	m_LowerThreshold

std::vector< double >	m_MaximumError

nsstd::auto_ptr< detail::MemberFunctionFactory< MemberFunctionType > >	m_MemberFactory

double	m_UpperThreshold

std::vector< double >	m_Variance

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 void	SetGlobalDefaultNumberOfThreads (unsigned int n)

static unsigned int	GetGlobalDefaultNumberOfThreads ()

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...

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) throw ()

virtual void	PreUpdate (itk::ProcessObject *p)

virtual void	RemoveITKObserver (EventCommand &e)

Protected Member Functions inherited from itk::simple::NonCopyable
	NonCopyable ()

Static Protected Member Functions inherited from itk::simple::ImageFilter< 1 >
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 TImageType >
static Image	CastITKToImage (TImageType *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)

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)

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 64 of file sitkCannyEdgeDetectionImageFilter.h.

Member Typedef Documentation

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

private

Setup for member function dispatching

Definition at line 144 of file sitkCannyEdgeDetectionImageFilter.h.

typedef RealPixelIDTypeList itk::simple::CannyEdgeDetectionImageFilter::PixelIDTypeList

Define the pixels types supported by this filter

Definition at line 76 of file sitkCannyEdgeDetectionImageFilter.h.

typedef CannyEdgeDetectionImageFilter itk::simple::CannyEdgeDetectionImageFilter::Self

Definition at line 66 of file sitkCannyEdgeDetectionImageFilter.h.

Constructor & Destructor Documentation

itk::simple::CannyEdgeDetectionImageFilter::CannyEdgeDetectionImageFilter ( )

Default Constructor that takes no arguments and initializes default parameters

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

Destructor

Member Function Documentation

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

Execute the filter on the input image

Image itk::simple::CannyEdgeDetectionImageFilter::Execute	(	const Image &	image1,
		double	lowerThreshold,
		double	upperThreshold,
		const std::vector< double > &	variance,
		const std::vector< double > &	maximumError
	)

Execute the filter on the input image with the given parameters

template<class TImageType >

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

private

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

inline

Definition at line 86 of file sitkCannyEdgeDetectionImageFilter.h.

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 124 of file sitkCannyEdgeDetectionImageFilter.h.

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

inlinevirtual

Name of this class

Implements itk::simple::ProcessObject.

Definition at line 126 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

Definition at line 96 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

Set/Get the variance of the Gaussian smoothing filter.

Definition at line 110 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

Definition at line 82 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

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

Definition at line 115 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

Set the values of the MaximumError vector all to value

Definition at line 118 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

Set the Threshold value for detected edges. TODO: Document in the ITKv4 migration guide that the SetThreshold member function was removed from the CannyEdgeDetectionImageFilter , and that both UpperThreshold and LowerThreshold need to be set. To get the same results as with the SetThreshold method change "myfilter->SetThrehsold" to "myfilter->SetUpperThreshold", and add "myfilter->SetLowerThreshold(GetUpperThreshold()/2.0)".

Definition at line 92 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

Set/Get the variance of the Gaussian smoothing filter.

Definition at line 101 of file sitkCannyEdgeDetectionImageFilter.h.

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

inline

Set the values of the Variance vector all to value

Definition at line 104 of file sitkCannyEdgeDetectionImageFilter.h.

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

virtual

Print ourselves out