Reconstruction class for 2D Filtered Back Projection. More...

#include "stir/analytic/FBP2D/FBP2DReconstruction.h"

Inheritance diagram for stir::FBP2DReconstruction:

[legend]

Public Member Functions
	FBP2DReconstruction ()
	Default constructor (calls set_defaults())

	FBP2DReconstruction (const std::string &parameter_filename)
	Constructor, initialises everything from parameter file, or (when parameter_filename == "") by calling ask_parameters().

	FBP2DReconstruction (const shared_ptr< ProjData > &, const double alpha_ramp=1., const double fc_ramp=.5, const int pad_in_s=2, const int num_segments_to_combine=-1)

std::string	method_info () const override
	gives method information

virtual void	ask_parameters ()

Succeeded	set_up (shared_ptr< TargetT > const &target_data_sptr) override
	operations prior to the reconstruction More...

Public Member Functions inherited from stir::RegisteredParsingObject< FBP2DReconstruction, Reconstruction< DiscretisedDensity< 3, float > >, AnalyticReconstruction >
std::string	get_registered_name () const override
	Returns Derived::registered_name.

std::string	parameter_info () override
	Returns a string with all parameters and their values, in a form suitable for parsing again.

Public Member Functions inherited from stir::AnalyticReconstruction
virtual DiscretisedDensity< 3, float > *	construct_target_image_ptr () const
	construct an image from parameters set (e.g. during parsing)

Succeeded	reconstruct () override
	reconstruct and write to file More...

Succeeded	reconstruct (shared_ptr< TargetT > const &target_image_sptr) override
	executes the reconstruction storing result in `target_image_sptr` More...

void	set_input_data (const shared_ptr< ExamData > &) override
	set input data

const ProjData &	get_input_data () const override
	get input data More...

int	get_output_image_size_xy () const

void	set_output_image_size_xy (int)

int	get_output_image_size_z () const

void	set_output_image_size_z (int)

float	get_zoom_xy () const

void	set_zoom_xy (float)

float	get_zoom_z () const

void	set_zoom_z (float)

const CartesianCoordinate3D< float > &	get_offset () const

void	set_offset (const CartesianCoordinate3D< float > &)

Public Member Functions inherited from stir::Reconstruction< DiscretisedDensity< 3, float > >
	Reconstruction ()
	default constructor (calls set_defaults())

	~Reconstruction () override
	virtual destructor

void	set_disable_output (bool _val)
	set_disable_output More...

shared_ptr< DiscretisedDensity< 3, float > >	get_target_image ()
	get_reconstructed_image More...

void	set_output_filename_prefix (const std::string &)
	file name for output reconstructed images

void	set_output_file_format_ptr (const shared_ptr< OutputFileFormat< DiscretisedDensity< 3, float > >> &)
	defines the format of the output files

void	set_post_processor_sptr (const shared_ptr< DataProcessor< DiscretisedDensity< 3, float > >> &)
	post-filter

Public Member Functions inherited from stir::ParsingObject
	ParsingObject (const ParsingObject &)

ParsingObject &	operator= (const ParsingObject &)

void	ask_parameters ()

bool	parse (std::istream &f)

bool	parse (const char *const filename)

Public Member Functions inherited from stir::TimedObject
void	reset_timers ()
	reset all timers kept by this object

void	stop_timers () const
	stop all timers kept by this object More...

void	start_timers (bool do_reset=false) const
	start all timers kept by this object More...

double	get_CPU_timer_value () const
	get current value of the CPU timer (since first use or last reset)

double	get_wall_clock_timer_value () const
	get current value of the wall-clock timer (since first use or last reset)

Static Public Attributes
static const char *const	registered_name = "FBP2D"
	Name which will be used when parsing a ProjectorByBinPair object.

Protected Attributes
double	alpha_ramp
	Ramp filter: Alpha value.

double	fc_ramp
	Ramp filter: Cut off frequency.

int	pad_in_s
	amount of padding for the filter (has to be 0,1 or 2)

int	num_segments_to_combine
	number of segments to combine (with SSRB) before starting 2D reconstruction More...

int	display_level
	potentially display data More...

Protected Attributes inherited from stir::AnalyticReconstruction
std::string	input_filename
	the input projection data file name

int	max_segment_num_to_process
	the maximum absolute ring difference number to use in the reconstruction More...

shared_ptr< ProjData >	proj_data_ptr
	points to the object for the total input projection data

ParseAndCreateFrom< TargetT, ProjData >	target_parameter_parser

Protected Attributes inherited from stir::Reconstruction< DiscretisedDensity< 3, float > >
std::string	output_filename_prefix
	file name for output reconstructed images

shared_ptr< OutputFileFormat< DiscretisedDensity< 3, float > > >	output_file_format_ptr
	defines the format of the output files

shared_ptr< DataProcessor< DiscretisedDensity< 3, float > > >	post_filter_sptr
	post-filter

bool	_already_set_up

shared_ptr< DiscretisedDensity< 3, float > >	target_data_sptr
	target_data_sptr

bool	_disable_output
	_disable_output More...

int	_verbosity
	Verbosity level.

Protected Attributes inherited from stir::ParsingObject
KeyParser	parser

Additional Inherited Members
Public Types inherited from stir::AnalyticReconstruction
typedef DiscretisedDensity< 3, float >	TargetT

Static Public Member Functions inherited from stir::RegisteredParsingObject< FBP2DReconstruction, Reconstruction< DiscretisedDensity< 3, float > >, AnalyticReconstruction >
static Reconstruction< DiscretisedDensity< 3, float > > *	read_from_stream (std::istream *)
	Construct a new object (of type Derived) by parsing the istream. More...

Static Public Member Functions inherited from stir::RegisteredObject< Reconstruction< DiscretisedDensity< 3, float > > >
static Reconstruction< DiscretisedDensity< 3, float > > *	read_registered_object (std::istream *in, const std::string &registered_name)
	Construct a new object (of a type derived from Root, its actual type determined by the registered_name parameter) by parsing the istream. More...

static Reconstruction< DiscretisedDensity< 3, float > > *	ask_type_and_parameters ()
	ask the user for the type, and then calls read_registered_object(0, type) More...

static void	list_registered_names (std::ostream &stream)
	List all possible registered names to the stream. More...

Protected Types inherited from stir::RegisteredObject< Reconstruction< DiscretisedDensity< 3, float > > >
typedef Reconstruction< DiscretisedDensity< 3, float > > (	RootFactory) (std::istream *)
	The type of a root factory is a function, taking an istream* as argument, and returning a Root*.

typedef FactoryRegistry< std::string, RootFactory, interfile_less >	RegistryType
	The type of the registry.

Protected Member Functions inherited from stir::AnalyticReconstruction
virtual Succeeded	actual_reconstruct (shared_ptr< TargetT > const &target_image_sptr)=0
	executes the reconstruction storing result in `target_image_sptr` More...

bool	post_processing () override
	used to check acceptable parameter ranges, etc...

void	set_defaults () override
	Set defaults before parsing.

void	initialise_keymap () override
	Initialise all keywords.

Protected Member Functions inherited from stir::Reconstruction< DiscretisedDensity< 3, float > >
virtual void	check (DiscretisedDensity< 3, float > const &target_data) const
	do consistency checks More...

void	initialise (const std::string &parameter_filename)
	This function initialises all parameters, either via parsing, or by calling ask_parameters() (when parameter_filename is the empty string). More...

void	set_defaults () override
	Set defaults before parsing.

void	initialise_keymap () override
	Initialise all keywords.

bool	post_processing () override
	used to check acceptable parameters after parsing More...

Protected Member Functions inherited from stir::ParsingObject
virtual void	set_key_values ()
	This will be called before parsing or parameter_info is called. More...

Static Protected Member Functions inherited from stir::RegisteredObject< Reconstruction< DiscretisedDensity< 3, float > > >
static RegistryType &	registry ()
	Static function returning the registry. More...

Detailed Description

Reconstruction class for 2D Filtered Back Projection.

Parameters

fbp2dparameters :=

input file := input.hs
output filename prefix := output

; output image parameters
; zoom defaults to 1
zoom := 1
; image size defaults to whole FOV
xy output image size (in pixels) := 180

; can be used to call SSRB first
; default means: call SSRB only if no axial compression is already present
;num segments to combine with ssrb := -1

; filter parameters, default to pure ramp
alpha parameter for ramp filter := 1
cut-off for ramp filter (in cycles) := 0.5

; allow less padding. DO NOT USE
; (unless you're sure that the object occupies only half the FOV)
;Transaxial extension for FFT:=1

; back projector that could be used (defaults to interpolating backprojector)
; Back projector type:= some type

; display data during processing for debugging purposes
; Display level := 0
end :=

alpha specifies the usual Hamming window (although I'm not so sure about the terminology here). So, for the "ramp filter" alpha =1. In frequency space, something like (from RampFilter.cxx)

(alpha + (1 - alpha) * cos(_PI * f / fc))

Member Function Documentation

◆ set_up()

Succeeded stir::FBP2DReconstruction::set_up ( shared_ptr< TargetT > const & target_data_sptr )

overridevirtual

operations prior to the reconstruction

Will do various consistency checks and return Succeeded::no if something is wrong.

Todo:: Currently, set_up() is called by reconstruct(). This is in contrast with some other class hierarchies in STIR where set_up() has to be called before any actual processing. Maybe this should be made consistent.

Reimplemented from stir::Reconstruction< DiscretisedDensity< 3, float > >.

References stir::error(), and stir::warning().

Referenced by stir::TestFBP2D::run_tests().

Member Data Documentation

◆ num_segments_to_combine

int stir::FBP2DReconstruction::num_segments_to_combine

protected

number of segments to combine (with SSRB) before starting 2D reconstruction

if -1, a value is chosen depending on the axial compression. If there is no axial compression, num_segments_to_combine is effectively set to 3, otherwise it is set to 1.

See also: SSRB

◆ display_level

int stir::FBP2DReconstruction::display_level

protected

potentially display data

allowed values: display_level=0 (no display), 1 (only final image), 2 (filtered-viewgrams). Defaults to 0.

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

/home/sirfuser/devel/STIRdistrib/STIR/src/include/stir/analytic/FBP2D/FBP2DReconstruction.h
/home/sirfuser/devel/STIRdistrib/STIR/src/analytic/FBP2D/FBP2DReconstruction.cxx

Public Member Functions

Static Public Attributes