Calculate normalized cross correlation using FFTs. More...

#include <sitkFFTNormalizedCorrelationImageFilter.h>

Inheritance diagram for itk::simple::FFTNormalizedCorrelationImageFilter:

Collaboration diagram for itk::simple::FFTNormalizedCorrelationImageFilter:

Public Types
typedef BasicPixelIDTypeList	PixelIDTypeList

typedef FFTNormalizedCorrelationImageFilter	Self

Public Types inherited from itk::simple::ImageFilter< 2 >
typedef ImageFilter	Self

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

Public Member Functions
Image	Execute (const Image &image1, const Image &image2)

Image	Execute (const Image &image1, const Image &image2, uint64_t requiredNumberOfOverlappingPixels)

	FFTNormalizedCorrelationImageFilter ()

std::string	GetName () const

uint64_t	GetRequiredNumberOfOverlappingPixels () const

Self &	SetRequiredNumberOfOverlappingPixels (uint64_t RequiredNumberOfOverlappingPixels)

std::string	ToString () const

	~FFTNormalizedCorrelationImageFilter ()

Public Member Functions inherited from itk::simple::ImageFilter< 2 >
	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, const Image &image2)

Private Member Functions
template<class TImageType >
Image	ExecuteInternal (const Image &image1, const Image &image2)

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

uint64_t	m_RequiredNumberOfOverlappingPixels

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< 2 >
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

Calculate normalized cross correlation using FFTs.

This filter calculates the normalized cross correlation (NCC) of two images using FFTs instead of spatial correlation. It is much faster than spatial correlation for reasonably large structuring elements. This filter is a subclass of the more general MaskedFFTNormalizedCorrelationImageFilter and operates by essentially setting the masks in that algorithm to images of ones. As described in detail in the references below, there is no computational overhead to utilizing the more general masked algorithm because the FFTs of the images of ones are still necessary for the computations.

Inputs: Two images are required as inputs, fixedImage and movingImage. In the context of correlation, inputs are often defined as: "image" and "template". In this filter, the fixedImage plays the role of the image, and the movingImage plays the role of the template. However, this filter is capable of correlating any two images and is not restricted to small movingImages (templates).

Optional parameters: The RequiredNumberOfOverlappingPixels enables the user to specify how many voxels of the two images must overlap; any location in the correlation map that results from fewer than this number of voxels will be set to zero. Larger values zero-out pixels on a larger border around the correlation image. Thus, larger values remove less stable computations but also limit the capture range. If RequiredNumberOfOverlappingPixels is set to 0, the default, no zeroing will take place.

Image size: fixedImage and movingImage need not be the same size. Furthermore, whereas some algorithms require that the "template" be smaller than the "image" because of errors in the regions where the two are not fully overlapping, this filter has no such restriction.

Image spacing: Since the computations are done in the pixel domain, all input images must have the same spacing.

Outputs; The output is an image of RealPixelType that is the NCC of the two images and its values range from -1.0 to 1.0. The size of this NCC image is, by definition, size(fixedImage) + size(movingImage) - 1.

Example filter usage:

typedef itk::FFTNormalizedCorrelationImageFilter< ShortImageType, DoubleImageType > FilterType;
FilterType::Pointer filter = FilterType::New();
filter->SetFixedImage( fixedImage );
filter->SetMovingImage( movingImage );
filter->SetRequiredNumberOfOverlappingPixels(20);
filter->Update();

Warning: The pixel type of the output image must be of real type (float or double). ConceptChecking is used to enforce the output pixel type. You will get a compilation error if the pixel type of the output image is not float or double.

References: 1) D. Padfield. "Masked object registration in the Fourier domain." Transactions on Image Processing. 2) D. Padfield. "Masked FFT registration". In Proc. Computer Vision and Pattern Recognition, 2010.

Author: : Dirk Padfield, GE Global Research, padfi.nosp@m.eld@.nosp@m.resea.nosp@m.rch..nosp@m.ge.co.nosp@m.m

See also: itk::simple::FFTNormalizedCorrelation for the procedural interface; itk::FFTNormalizedCorrelationImageFilter for the Doxygen on the original ITK class.

Definition at line 75 of file sitkFFTNormalizedCorrelationImageFilter.h.

Member Typedef Documentation

typedef Image(Self::* itk::simple::FFTNormalizedCorrelationImageFilter::MemberFunctionType) (const Image &image1, const Image &image2)

private

Setup for member function dispatching

Definition at line 117 of file sitkFFTNormalizedCorrelationImageFilter.h.

typedef BasicPixelIDTypeList itk::simple::FFTNormalizedCorrelationImageFilter::PixelIDTypeList

Define the pixels types supported by this filter

Definition at line 87 of file sitkFFTNormalizedCorrelationImageFilter.h.

typedef FFTNormalizedCorrelationImageFilter itk::simple::FFTNormalizedCorrelationImageFilter::Self

Definition at line 77 of file sitkFFTNormalizedCorrelationImageFilter.h.

Constructor & Destructor Documentation

itk::simple::FFTNormalizedCorrelationImageFilter::FFTNormalizedCorrelationImageFilter ( )

Default Constructor that takes no arguments and initializes default parameters

itk::simple::FFTNormalizedCorrelationImageFilter::~FFTNormalizedCorrelationImageFilter ( )

Destructor

Member Function Documentation

Image itk::simple::FFTNormalizedCorrelationImageFilter::Execute	(	const Image &	image1,
		const Image &	image2
	)

Execute the filter on the input images

Image itk::simple::FFTNormalizedCorrelationImageFilter::Execute	(	const Image &	image1,
		const Image &	image2,
		uint64_t	requiredNumberOfOverlappingPixels
	)