Detailed Description

Pre-processing of projection images.

X-Ray projection images have to be normalized and, if selected, converted from detector intensity to attenuation values. For that purpose, the following steps are applied in order, given that the respective image frames have been provided by the user: 1) Substraction of minFrame 2) Division by (maxFrame - minFrame) 3) Filling gaps due to bad detector pixels (according to mask) 4) Rescaling to full image range, at the same time conversion to attenuation values (if selected)

Steps 1-3 have to be executed in a dry run in order to compute the resulting intensity range, before the actual conversion is applied to all projection images.

Public Member Functions
	ProjectionPreProcessing (SharedImageSet &images)
	Constructor requiring the vector of projection images.

void	setInputDepth (int depth)
	Specifies the bit depth of the input data in order to detect and skip saturated pixels.

void	setAirValue (int val)
	Specifies the air value (more precise upper value than using bit depth)

void	setWaterPreCorrectCoeffs (std::vector< double > coeffs)
	Sepcifies the coefficients for the polynomial (with the projections as variable) for the water pre-correction in order to reduce beam hardening.

void	init (int numFrames, bool background=true)
	Prepare for parallel pre-processing with the given maximum number of frames.

void	scheduleFrame (int which)
	Schedule the multi-threaded pre-processing of a single frame.

void	processFrame (int which)
	Thread-safe method to process a single frame.

void	process (Progress *progress=0)
	Processes all projection images according to the chosen settings.

double	getMaxTexVal () const
	Return the maximum texture value in all of the images.

std::mutex *	mutex ()
	Return pointer to the mutex for image synchronization.

void	configure (const Properties *p) override
	Set pre-processing configuration from properties.

void	configuration (Properties *p) const override
	Retrieve the current configuration as properties.

void	options (bool &orig, bool &downsample, int &rotate, int &flip) const
	Directly retrieve some configuration options.

Public Member Functions inherited from Configurable
virtual void	configureDefaults ()
	Retrieve the properties of this object, replaces values with their defaults and sets it again.

void	registerParameter (ParameterBase *param)
	Register the given Parameter or SubProperty, so that it will be configured during configure()/configuration().

void	unregisterParameter (const ParameterBase *param)
	Remove the given Parameter or SubProperty from the list of registered parameters.

	Configurable (const Configurable &rhs)

	Configurable (Configurable &&rhs) noexcept

Configurable &	operator= (const Configurable &)

Configurable &	operator= (Configurable &&) noexcept

Static Public Member Functions
static int	applyMask (MemImage img, TypedImage< unsigned char > mask)
	Fill gaps using mask from a single frame.

Protected Member Functions
void	computeGlobalGain ()

template<typename T>
void	convertFrame (TypedImage< T > img, bool apply, double &minOut, double &maxOut, const Mask imageMask=nullptr)
	Converts a single frame, either computing resulting range or applying the conversion.

Protected Attributes
SharedImageSet &	m_images
	Reference to vector of projection images.

std::vector< double >	m_frameMin
	Per-frame minimum intensity.

std::vector< double >	m_frameMax
	Per-frame maximum intensity.

std::vector< double >	m_waterPreCorrectCoeffs
	Polynomial coefficients for water pre-correction.

double	m_minVal
	Minimum intensity in all of the images.

double	m_maxVal
	Maximum intensity in all of the images.

double	m_maxTexVal
	Maximum resulting texture intensity in all images.

TypedImage< unsigned char > *	m_mask
	Mask frame denoting bad detector pixels.

bool	m_deleteMask
	Delete mask on destruction.

bool	m_origVal
	Are original values kept (no conversion to attenuation)

bool	m_rotateLeft
	Are the images rotated.

bool	m_rotateRight
	Are the images rotated.

bool	m_flipHorizontal
	Are the images flipped.

bool	m_flipVertical
	Are the images flipped.

bool	m_downSample
	Are the images downsampled.

bool	m_scaleIntensities
	Specifies whether intensity scaling is applied after conversion when loading original values.

bool	m_secondPass
	True if this is the second pass through the images.

bool	m_onePass
	True if we shall only use one pass.

double	m_intensityScale
	Computed scale value applied to the images.

double	m_intensityShift
	Computed shift value applied to the images.

vec4i	m_crop
	If non-zero, image borders are cropped.

TypedImage< float > *	m_offsetMap
	Offset map.

std::vector< TypedImage< float > * >	m_gainMaps
	Gain maps for multipoint gain correction.

std::vector< double >	m_globalGain
	Mean value of each gain map.

int	m_depth
	Bit depth of the data, if provided.

int	m_airValue
	Air value, if provided.

std::mutex	m_mutex
	Synchronizing multi-threaded access to image data.

std::unique_ptr< Threading::ThreadPool >	m_threadpool
	Processing threads.

Protected Attributes inherited from Configurable
std::vector< Param >	m_params
	List of all registered Parameter and SubProperty instances.

Set methods to provide min/max/mask frames and options
void	setOffsetMap (TypedImage< float > *offsetMap)

TypedImage< float > *	offsetMap ()

void	setGainMaps (const std::vector< TypedImage< float > * > &gainMaps)
	Set gain maps for multi-point gain correction.

const std::vector< TypedImage< float > * > &	gainMaps ()

void	setMask (TypedImage< unsigned char > *mask)
	Specifies a mask of bad pixels.

void	setMask (const MemImage *img, int threshold)

TypedImage< unsigned char > *	mask ()

void	setOrigVal (bool flag)
	If true, no conversion into attenuation values is done.

void	setRotateLeft (bool flag)
	If true, projections are rotated 90 degrees counter-clockwise.

void	setRotateRight (bool flag)
	If true, projections are rotated 90 degrees clockwise.

void	setFlipHorizontal (bool flag)
	If true, projections are horizontally flipped (after optional rotation)

void	setFlipVertical (bool flag)
	If true, projections are vertically flipped (after optional rotation)

void	setDownSample (bool flag)
	If true, downsampling by two is executed both in width and height.

void	setScaleIntensities (bool scaleIntensities)
	Specifies whether intensity scaling is applied after conversion when loading original values.

void	setCropping (const vec4i &borders)
	Specifies optional cropping of the image borders.

Additional Inherited Members
Public Attributes inherited from Configurable
Signal	signalParametersChanged
	Emitted whenever one of the registered Parameters' or SubPropertys' `signalValueChanged` signal was emitted.

Member Function Documentation

◆ setOffsetMap()

void setOffsetMap ( TypedImage< float > * offsetMap )

Set offset map for multi-point gain correction

◆ setMask()

void setMask ( TypedImage< unsigned char > * mask )

inline

Specifies a mask of bad pixels.

If the mask value is below the specified threshold, the pixel is discarded and filled from neighboring values, if possible.

◆ configure()

void configure ( const Properties * p )

overridevirtual

Set pre-processing configuration from properties.

Reimplemented from Configurable.

◆ configuration()

void configuration ( Properties * p ) const

overridevirtual

Retrieve the current configuration as properties.

Reimplemented from Configurable.

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

ImFusion/CT/Legacy/ProjectionPreProcessing.h

Detailed Description

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Set methods to provide min/max/mask frames and options

Additional Inherited Members

Member Function Documentation

◆ setOffsetMap()

◆ setMask()

◆ configure()

◆ configuration()