A class for handling motion information from the Polaris tracker. More...

#include "stir_experimental/motion/RigidObject3DMotionFromPolaris.h"

Inheritance diagram for stir::RigidObject3DMotionFromPolaris:

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Public Member Functions
RigidObject3DTransformation	compute_average_motion_in_tracker_coords_rel_time (const double start_time, const double end_time) const override

RigidObject3DTransformation	get_motion_in_tracker_coords_rel_time (const double time) const override
	get motion in tracker coordinates

std::vector< double >	get_rel_time_of_samples (const double start_time, const double end_time) const override
	Info on when the motion was determined. More...

void	set_mask_for_tags (const unsigned int mask_for_tags)
	set mask to be able to ignore one or more channels in the listmode gating data

Succeeded	synchronise () override
	Synchronise motion tracking file and listmode file.

double	secs_since_1970_to_rel_time (std::time_t) const override

const RigidObject3DTransformation &	get_transformation_to_scanner_coords () const override

const RigidObject3DTransformation &	get_transformation_from_scanner_coords () const override

void	set_transformation_from_scanner_coords (const RigidObject3DTransformation &) override

Succeeded	set_mt_file (const std::string &mt_filename)

Succeeded	set_list_mode_data_file (const std::string &lm_filename)

void	set_defaults () override
	Set defaults before parsing.

void	initialise_keymap () override
	Initialise all keywords.

bool	post_processing () override
	This will be called at the end of the parsing. More...

double	get_max_time_offset_deviation () const
	Gets boundaries to determine when the time offset is out of bounds.

void	set_max_time_offset_deviation (const double v)
	Sets boundaries to determine when the time offset is out of bounds.

double	get_max_time_drift_deviation () const
	Gets boundaries to determine when the time drift is too large. More...

void	set_max_time_drift_deviation (const double v)
	Sets boundaries to determine when the time drift is too large.

Public Member Functions inherited from stir::RegisteredParsingObject< RigidObject3DMotionFromPolaris, RigidObject3DMotion, RigidObject3DMotion >
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::RigidObject3DMotion
virtual RigidObject3DTransformation	get_motion_in_scanner_coords_rel_time (const double time) const
	get motion in scanner coordinates

virtual RigidObject3DTransformation	compute_average_motion_in_tracker_coords (const AbsTimeInterval &) const

virtual RigidObject3DTransformation	compute_average_motion_in_scanner_coords (const AbsTimeInterval &) const

virtual RigidObject3DTransformation	compute_average_motion_in_scanner_coords_rel_time (const double start_time, const double end_time) const

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)

Static Public Member Functions
static RigidObject3DTransformation	make_transformation_from_polaris_data (Polaris_MT_File::Record const &record)
	Convert from Polaris transformation to STIR conventions. More...

Static Public Member Functions inherited from stir::RegisteredParsingObject< RigidObject3DMotionFromPolaris, RigidObject3DMotion, RigidObject3DMotion >
static RigidObject3DMotion *	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< RigidObject3DMotion >
static RigidObject3DMotion *	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 RigidObject3DMotion *	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...

Static Public Attributes
static const char *const	registered_name = "Motion From Polaris"
	Name which will be used when parsing a MotionTracking object.

Additional Inherited Members
Protected Types inherited from stir::RegisteredObject< RigidObject3DMotion >
typedef RigidObject3DMotion (	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::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< RigidObject3DMotion >
static RegistryType &	registry ()
	Static function returning the registry. More...

Protected Attributes inherited from stir::ParsingObject
KeyParser	parser

Detailed Description

A class for handling motion information from the Polaris tracker.

Implements synchronisation by comparing gate data in the list mode file with the numbers stored in the Polaris .mt file. Computes both time offset and clock drift. Synchronisation is stored in a .sync file. If present, this file is read and actual synchronisation is skipped. (This is useful, as the synchronisation is slow as it walks through the whole list mode file).

Parsing info

The class can parse a file for the coordinate transformation that goes from scanner to tracker coordinates. This file has to have the following format.

  Move from scanner to tracker coordinates:=
   conventions := q0qzqyqx and left-handed
   transformation:= \
    {{-0.00525584, -0.0039961, 0.999977,0.00166456},\
     {-1981.93, 20.1226, 3.96638}}
 end:=

Obviously the numbers will depend on your systems.

Todo:: move synchronisation out of this class

Member Function Documentation

◆ make_transformation_from_polaris_data()

RigidObject3DTransformation stir::RigidObject3DMotionFromPolaris::make_transformation_from_polaris_data ( Polaris_MT_File::Record const & record )

static

Convert from Polaris transformation to STIR conventions.

Convert from Polaris transformation to STIR conventions

The Polaris records info as q0 qx qy qz tx ty tz, where the coordinate system is right-handed (see the Polaris manual). The STIR coordinate system is left-handed. We do take a coordinate transformation into account when applying Polaris transformations to scanner coordinates. However, that coordinate transformation uses RigidObject3DTransformation, and hence cannot swap right-handed to left-handed. So, we convert the Polaris transformation to a left-handed transformation by swapping x and y.

The exact form then depends heavily on conventions in RigidObject3DTransformation, which currently takes its info as

Quaternion<float>(q0,qZ,qY,qX), CartesianCoordinate3D<float>(tZ,tY,tX)

where I've used capitals to denote the left-handed coordinate system:

x=Y,y=X,z=Z.

Some careful checks in e.g. Mathematica then show that

qx=qY,qy=qX,qz=qZ.

This not so obvious as it sounds as there is a potential sign here. For instance, the Polaris convention uses a quaternion (0,x,y,z) for a point, while RigidObject3DTransformation uses (0,z,y,x) (see the point2quat function in RigidObject3DTransformation.cxx ). So, effectively there are 2 coordinate swaps between Polaris conventions and RigidObject3DTransformation:

Quaternion<float>(q0,qZ,qY,qX) = Quaternion<float>(q0,qz,qx,qy)

and qz,qx,qy is an even permutation of qx,qy,qz

◆ get_rel_time_of_samples()

std::vector< double > stir::RigidObject3DMotionFromPolaris::get_rel_time_of_samples	(	const double	start_time,
		const double	end_time
	)		const

overridevirtual

Info on when the motion was determined.

Will return a vector of doubles filled with the sampling times between start_time and end_time.

Todo:: Really only makes sense for motion tracking that happens via sampling. One could imagine having simulated motion, and then this function wouldn't make a lot of sense. So, it probably should be moved to a derived class SampledRigidObject3DMotion or so.

Implements stir::RigidObject3DMotion.

References stir::error(), stir::RigidObject3DTransformation::get_quaternion(), stir::RigidObject3DTransformation::get_translation(), stir::norm(), and stir::warning().

◆ post_processing()

bool stir::RigidObject3DMotionFromPolaris::post_processing ( )

overridevirtual

This will be called at the end of the parsing.

Returns: false if everything OK, true if not

Reimplemented from stir::RigidObject3DMotion.

References stir::KeyParser::add_key(), stir::KeyParser::add_start_key(), stir::KeyParser::add_stop_key(), stir::norm(), stir::KeyParser::parse(), and stir::warning().

◆ get_max_time_drift_deviation()

double stir::RigidObject3DMotionFromPolaris::get_max_time_drift_deviation ( ) const

inline

Gets boundaries to determine when the time drift is too large.

deviation is measured as fabs(time_drift-1)

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

/home/sirfuser/devel/STIRdistrib/STIR/src/include/stir_experimental/motion/RigidObject3DMotionFromPolaris.h
/home/sirfuser/devel/STIRdistrib/STIR/src/experimental/motion/RigidObject3DMotionFromPolaris.cxx

Public Member Functions

Static Public Member Functions