Alter an image with shot noise. More...

#include <sitkShotNoiseImageFilter.h>

Inheritance diagram for itk::simple::ShotNoiseImageFilter:

Collaboration diagram for itk::simple::ShotNoiseImageFilter:

Detailed Description

Alter an image with shot noise.

The shot noise follows a Poisson distribution:

: \( I = N(I_0) \)

: where \( N(I_0) \) is a Poisson-distributed random variable of mean \( I_0 \) . The noise is thus dependent on the pixel intensities in the image.

The intensities in the image can be scaled by a user provided value to map pixel values to the actual number of particles. The scaling can be seen as the inverse of the gain used during the acquisition. The noisy signal is then scaled back to its input intensity range:

: \( I = \frac{N(I_0 \times s)}{s} \)

: where \( s \) is the scale factor.

The Poisson-distributed variable \( \lambda \) is computed by using the algorithm:

: \( \begin{array}{l} k \leftarrow 0 \\ p \leftarrow 1 \\ \textbf{repeat} \\ \left\{ \begin{array}{l} k \leftarrow k+1 \\ p \leftarrow p \ast U() \end{array} \right. \\ \textbf{until } p > e^{\lambda} \\ \textbf{return} (k) \end{array} \)

: where \( U() \) provides a uniformly distributed random variable in the interval \( [0,1] \) .

This algorithm is very inefficient for large values of \( \lambda \) , though. Fortunately, the Poisson distribution can be accurately approximated by a Gaussian distribution of mean and variance \( \lambda \) when \( \lambda \) is large enough. In this implementation, this value is considered to be 50. This leads to the faster algorithm:

: \( \lambda + \sqrt{\lambda} \times N()\)

: where \( N() \) is a normally distributed random variable of mean 0 and variance 1.

Author: Gaetan Lehmann

This code was contributed in the Insight Journal paper "Noise Simulation". https://doi.org/10.54294/vh6vbw

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

Definition at line 85 of file sitkShotNoiseImageFilter.h.

Public Types
using	PixelIDTypeList = BasicPixelIDTypeList

using	Self = ShotNoiseImageFilter

Public Types inherited from itk::simple::ImageFilter
using	Self = ImageFilter

Public Types inherited from itk::simple::ProcessObject
using	Self = ProcessObject

Public Member Functions
Image	Execute (const Image &image1)

Image	Execute (Image &&image1)

std::string	GetName () const

double	GetScale () const

uint32_t	GetSeed () const

Self &	SetScale (double Scale)

Self &	SetSeed (uint32_t Seed)

	ShotNoiseImageFilter ()

std::string	ToString () const

virtual	~ShotNoiseImageFilter ()

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.

virtual int	AddCommand (itk::simple::EventEnum event, itk::simple::Command &cmd)
	Add a Command Object to observer the event.

virtual float	GetProgress () const
	An Active Measurement of the progress of execution.

virtual bool	HasCommand (itk::simple::EventEnum event) const
	Query of this object has any registered commands for event.

	ProcessObject ()

virtual void	RemoveAllCommands ()
	Remove all registered commands.

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)

template<class TImageType>
Image	ExecuteInternalVectorImage (const Image &image)

Private Attributes
bool	m_InPlace {false}

std::unique_ptr< detail::MemberFunctionFactory< MemberFunctionType > >	m_MemberFactory

double	m_Scale {1.0}

uint32_t	m_Seed {(uint32_t) itk::simple::sitkWallClock}

Friends
struct	detail::ExecuteInternalVectorImageAddressor< MemberFunctionType >

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.

static void	SetGlobalDefaultCoordinateTolerance (double)
	Access the global tolerance to determine congruent spaces.

static double	GetGlobalDefaultDirectionTolerance ()
	Access the global tolerance to determine congruent spaces.

static void	SetGlobalDefaultDirectionTolerance (double)
	Access the global tolerance to determine congruent spaces.

static bool	SetGlobalDefaultThreader (const std::string &threader)
	Set/Get the default threader used for process objects.

static std::string	GetGlobalDefaultThreader ()
	Set/Get the default threader used for process objects.

static void	SetGlobalDefaultNumberOfThreads (unsigned int n)

static unsigned int	GetGlobalDefaultNumberOfThreads ()
	Set/Get the default threader used for process objects.

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::ShotNoiseImageFilter::MemberFunctionType = Image (Self::*)( const Image& image1 )

private

Setup for member function dispatching

Definition at line 135 of file sitkShotNoiseImageFilter.h.

◆ PixelIDTypeList

using itk::simple::ShotNoiseImageFilter::PixelIDTypeList = BasicPixelIDTypeList

Define the pixels types supported by this filter

Definition at line 97 of file sitkShotNoiseImageFilter.h.

◆ Self

using itk::simple::ShotNoiseImageFilter::Self = ShotNoiseImageFilter

Definition at line 87 of file sitkShotNoiseImageFilter.h.

Constructor & Destructor Documentation

◆ ~ShotNoiseImageFilter()

virtual itk::simple::ShotNoiseImageFilter::~ShotNoiseImageFilter ( )

virtual

Destructor

◆ ShotNoiseImageFilter()

itk::simple::ShotNoiseImageFilter::ShotNoiseImageFilter ( )

Default Constructor that takes no arguments and initializes default parameters

Member Function Documentation

◆ Execute() [1/2]

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

◆ Execute() [2/2]

Image itk::simple::ShotNoiseImageFilter::Execute ( Image && image1 )

Execute the filter on the input image

◆ ExecuteInternal()

template<class TImageType>

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

private

◆ ExecuteInternalVectorImage()

template<class TImageType>

Image itk::simple::ShotNoiseImageFilter::ExecuteInternalVectorImage ( const Image & image )

private

Dispatched methods which calls ExecuteInternal on each component

Referenced by detail::ExecuteInternalVectorImageAddressor< MemberFunctionType >.

◆ GetName()

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

inlinevirtual

Name of this class

Implements itk::simple::ProcessObject.

Definition at line 119 of file sitkShotNoiseImageFilter.h.

◆ GetScale()

double itk::simple::ShotNoiseImageFilter::GetScale ( ) const

inline

Set/Get the value to map the pixel value to the actual particle counting. The scaling can be seen as the inverse of the gain used during the acquisition. The noisy signal is then scaled back to its input intensity range. Defaults to 1.0.

Definition at line 108 of file sitkShotNoiseImageFilter.h.

References m_Scale.

◆ GetSeed()

uint32_t itk::simple::ShotNoiseImageFilter::GetSeed ( ) const

inline

Definition at line 116 of file sitkShotNoiseImageFilter.h.

References m_Seed.

◆ SetScale()

Self & itk::simple::ShotNoiseImageFilter::SetScale ( double Scale )

inline

Set/Get the value to map the pixel value to the actual particle counting. The scaling can be seen as the inverse of the gain used during the acquisition. The noisy signal is then scaled back to its input intensity range. Defaults to 1.0.

Definition at line 103 of file sitkShotNoiseImageFilter.h.

References m_Scale.