The DetectorSaturationExtension class is an extension for forward projectors that considers over- and/or undersaturation effects of the detector. More...

#include <detectorsaturationextension.h>

Inheritance diagram for CTL::DetectorSaturationExtension:

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Collaboration diagram for CTL::DetectorSaturationExtension:

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Public Types
enum	{ Type = 102 }

Public Types inherited from CTL::ProjectorExtension
enum	{ Type = 100 }

Public Types inherited from CTL::AbstractProjector
enum	{ Type = 0 }

Public Types inherited from CTL::SerializationInterface
enum	{ Type = -1, UserType = 65536 }

Public Member Functions
int	type () const override

void	configure (const AcquisitionSetup &setup) override
	Configures the projector. More...

	DetectorSaturationExtension (uint nbSpectralSamples)

bool	isLinear () const override

void	setIntensitySampling (uint nbSamples)

QVariant	toVariant () const override
	Stores the contents of this instance in a QVariant. More...

QVariant	parameter () const override

void	setParameter (const QVariant &parameter) override
	Sets the parameters of this instance based on the passed QVariant parameter. Parameters need to follow the naming convention as described in parameter(). More...

	ProjectorExtension (AbstractProjector *projector=nullptr)

	ProjectorExtension (std::unique_ptr< AbstractProjector > projector)

Public Member Functions inherited from CTL::ProjectorExtension
int	type () const override

void	configure (const AcquisitionSetup &setup) override

ProjectionData	project (const VolumeData &volume) override

	ProjectorExtension (AbstractProjector *projector=nullptr)

	ProjectorExtension (std::unique_ptr< AbstractProjector > projector)

ProjectionData	projectComposite (const CompositeVolume &volume) override
	Provides the functionality to forward project CompositeVolume data. More...

ProjectionData	projectSparse (const SparseVoxelVolume &volume) override
	Provides the functionality to forward project SparseVoxelVolume data. More...

bool	isLinear () const override
	Returns true if the projection operation is linear. More...

virtual void	use (AbstractProjector *other)

void	use (std::unique_ptr< AbstractProjector > other)

void	fromVariant (const QVariant &variant) override
	Sets the contents of the object based on the QVariant variant. More...

QVariant	toVariant () const override
	Stores the contents of this instance in a QVariant. More...

AbstractProjector *	release ()

void	reset ()

Public Member Functions inherited from CTL::AbstractProjector
	AbstractProjector (const AbstractProjector &)=delete

	AbstractProjector (AbstractProjector &&)=default

AbstractProjector &	operator= (const AbstractProjector &)=delete

AbstractProjector &	operator= (AbstractProjector &&)=default

	~AbstractProjector () override=default

ProjectionData	configureAndProject (const AcquisitionSetup &setup, const VolumeData &volume)
	Performs a forward projection with a precedent configuration of the projector. More...

ProjectionData	configureAndProject (const AcquisitionSetup &setup, const CompositeVolume &volume)
	Performs a forward projection with a precedent configuration of the projector. More...

ProjectionData	configureAndProject (const AcquisitionSetup &setup, const SparseVoxelVolume &volume)
	Performs a forward projection with a precedent configuration of the projector. More...

virtual ProjectorNotifier *	notifier ()
	Returns a pointer to the notifier of the projector. More...

void	connectNotifierToMessageHandler (bool includeProgress=false)
	Connects the notifier to the CTL's MessageHandler. More...

Public Member Functions inherited from CTL::SerializationInterface
virtual	~SerializationInterface ()=default

Protected Member Functions
ProjectionData	extendedProject (const MetaProjector &nestedProjector) override

Protected Member Functions inherited from CTL::SerializationInterface
	SerializationInterface ()=default

	SerializationInterface (const SerializationInterface &)=default

	SerializationInterface (SerializationInterface &&)=default

SerializationInterface &	operator= (const SerializationInterface &)=default

SerializationInterface &	operator= (SerializationInterface &&)=default

Private Member Functions
void	processCounts (ProjectionData &projections)

void	processExtinctions (ProjectionData &projections)

void	processIntensities (ProjectionData &projections)

Private Attributes
AcquisitionSetup	_setup
	A copy of the acquisition setup.

uint	_nbSamples { 0u }
	Number of samples used to extract spectrally resolved information.

Friends
template<class >
struct	SerializationHelper::RegisterWithSerializationHelper

Additional Inherited Members
Related Functions inherited from CTL::ProjectorExtension
std::unique_ptr< ProjectorExtensionType >	makeExtension (AbstractProjector *projector=nullptr)

std::unique_ptr< ProjectorExtensionType >	makeExtension (std::unique_ptr< AbstractProjector > projector)

Related Functions inherited from CTL::AbstractProjector
	VolumeData
	Alias name for CTL::SpectralVolumeData. More...

std::unique_ptr< ProjectorType >	makeProjector (ConstructorArguments &&... arguments)

Detailed Description

The DetectorSaturationExtension class is an extension for forward projectors that considers over- and/or undersaturation effects of the detector.

This extension performs a postprocessing on the projection data to consider over- and/or undersaturation effects of the detector. It will use the saturation model set to the detector component (see AbstractDetector::setSaturationModel()). Depending on the specification of the saturation model, the postprocessing will be applied in the domain of extinction values, intensities, or photon counts.

The following example shows how to extend a simple ray caster algorithm to consider detector (over- and under-) saturation:

 // define volume and acquisition setup (incl. system)
auto volume = VolumeData::cube(100, 1.0f, 0.02f);
auto system = SimpleCTSystem::fromCTSystem(CTSystemBuilder::createFromBlueprint(blueprints::GenericCarmCT(DetectorBinning::Binning4x4)));
AcquisitionSetup acquisitionSetup(system, 10);
acquisitionSetup.applyPreparationProtocol(protocols::ShortScanTrajectory(750.0));
// Core part
// set a detector saturation model (operating in extinction domain, clamps values to [0.1, 2.5])
auto saturationModel = new DetectorSaturationLinearModel(0.1f, 2.5f);
acquisitionSetup.system()->detector()->setSaturationModel(saturationModel, AbstractDetector::Extinction);
auto simpleProjector = new RayCasterProjector; // our simple projector
    // optional parameter settings for the projector
    // e.g. simpleProjector->settings().raySampling = 0.1f;
// This is what we do without the extension:
    // simpleProjector->configure(acquisitionSetup);
    // ProjectionData projections = simpleProjector->project(volume);
    // qInfo() << projections.min() << projections.max(); // output: 0 2.79263
// Instead we now do the following:
DetectorSaturationExtension* extension = new DetectorSaturationExtension;
extension->use(simpleProjector);                            // tell the extension to use the ray caster
extension->configure(acquisitionSetup);                     // configure the simulation
ProjectionData projections = extension->project(volume);    // (compute and) get the final projections
qInfo() << projections.min() << projections.max();          // output: 0.1 2.5

Constructor & Destructor Documentation

◆ DetectorSaturationExtension()

CTL::DetectorSaturationExtension::DetectorSaturationExtension ( uint nbSpectralSamples )

explicit

Constructs a DetectorSaturationExtension and sets the number of samples used when (internally) a spectrum needs to be sampled to nbSpectralSamples.

Member Function Documentation

◆ configure()

void CTL::DetectorSaturationExtension::configure ( const AcquisitionSetup & setup )

overridevirtual

Configures the projector.

This method should be used to gather all necessary information to prepare the actual forward projection. This usually contains all geometry and system information, which can be retrieved from setup.

If you intend to call configure() and project() (or projectComposite()) directly after each other, you should use configureAndProject() instead.

Implements CTL::AbstractProjector.

◆ extendedProject()

ProjectionData CTL::DetectorSaturationExtension::extendedProject ( const MetaProjector & nestedProjector )

overrideprotectedvirtual

Performs the extension of the projection step by means of postprocessing the projection data created by nestedProjector. This allows for handling the cases of single and composite volumes in the same fashion.

Reimplemented from CTL::ProjectorExtension.

◆ isLinear()

bool CTL::DetectorSaturationExtension::isLinear ( ) const

overridevirtual

Returns false, because in general, detector saturation effects are non-linear.

Reimplemented from CTL::AbstractProjector.

◆ parameter()

QVariant CTL::DetectorSaturationExtension::parameter ( ) const

overridevirtual

Returns the parameters of this instance as QVariant.

This returns a QVariantMap with one key-value-pair: ("Intensity sampling points", _nbSamples), which represents the number of sampling points used when (internally) a spectrum needs to be sampled.

This method is used within toVariant() to serialize the object's settings.

Reimplemented from CTL::AbstractProjector.

◆ processCounts()

void CTL::DetectorSaturationExtension::processCounts ( ProjectionData & projections )

private

Applies the detector saturation model to projections in the photon count domain. Transformation of input extinction data from projections to counts is based on the incident photon count queried from the system (see SimpleCTSystem::photonsPerPixel()).

◆ processExtinctions()

void CTL::DetectorSaturationExtension::processExtinctions ( ProjectionData & projections )

private

Applies the detector saturation model to projections in the extinction domain.

◆ processIntensities()

void CTL::DetectorSaturationExtension::processIntensities ( ProjectionData & projections )

private

Applies the detector saturation model to projections in the intensity domain. Transformation of input extinction data from projections to intensities is based on the incident photon count queried from the system (see SimpleCTSystem::photonsPerPixel()) multiplied by the mean energy in the incident X-ray spectrum. Note that this is an approximation. Ideally, the final radiation spectrum reaching the detector would be considered instead.

◆ ProjectorExtension() [1/2]

CTL::ProjectorExtension::ProjectorExtension

explicit

Constructs a ProjectorExtension object and sets the nested projector to projector. A good practice to create a ProjectorExtension on the heap is to use the make function makeExtension(std::unique_ptr<AbstractProjector> projector) which will interally use this constructor.

◆ ProjectorExtension() [2/2]

CTL::ProjectorExtension::ProjectorExtension

explicit

Constructs a ProjectorExtension object and sets the nested projector to projector. The nested projector is internally used as a basis for computing forward projections. Note that the constructed object takes over the ownership of projector.

◆ setIntensitySampling()

void CTL::DetectorSaturationExtension::setIntensitySampling ( uint nbSamples )

Sets the number of samples used when (internally) a spectrum needs to be sampled to nbSpectralSamples. This has no meaning if the saturation model set for the detector is specified in the extinction domain (because processing extinctions does not require computation of a spectrum at any point).

If nbSamples = 0, the sampling hint from the source component will be used (see AbstractSource::spectrumDiscretizationHint().

◆ setParameter()

void CTL::DetectorSaturationExtension::setParameter ( const QVariant & parameter )

overridevirtual

Sets the parameters of this instance based on the passed QVariant parameter. Parameters need to follow the naming convention as described in parameter().

This method is used within fromVariant() to deserialize the object's settings. Direct use of this method is discouraged; consider using dedicated setter methods instead.

Reimplemented from CTL::AbstractProjector.

◆ toVariant()

QVariant CTL::DetectorSaturationExtension::toVariant ( ) const

overridevirtual

Stores the contents of this instance in a QVariant.

Implementation of the serialization interface. Stores the object's type-id (from SerializationInterface::toVariant()).

This method uses parameter() to serialize class members.

Reimplemented from CTL::AbstractProjector.

◆ type()

int CTL::DetectorSaturationExtension::type ( ) const

inlineoverridevirtual

Returns the type-id of the serializable object. Used in deserialization to determine the proper object type.

Add derived classes to the enumeration using the CTL_TYPE_ID macro.

Reimplemented from CTL::AbstractProjector.

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

modules/src/projectors/detectorsaturationextension.h
modules/src/projectors/detectorsaturationextension.cpp

Public Types

Public Member Functions

Protected Member Functions

Private Member Functions

Private Attributes

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ DetectorSaturationExtension()

Member Function Documentation

◆ configure()

◆ extendedProject()

◆ isLinear()

◆ parameter()

◆ processCounts()

◆ processExtinctions()

◆ processIntensities()

◆ ProjectorExtension() [1/2]

◆ ProjectorExtension() [2/2]

◆ setIntensitySampling()

◆ setParameter()

◆ toVariant()

◆ type()