This class contains the Colsher filter used for 3D-PET reconstruction. More...

#include "stir/analytic/FBP3DRP/ColsherFilter.h"

Inheritance diagram for stir::ColsherFilter:

[legend]

Public Member Functions
	ColsherFilter ()
	Default constructor. More...

	ColsherFilter (float theta_max, float alpha_colsher_axial=1.F, float fc_colsher_axial=0.5F, float alpha_colsher_radial=1.F, float fc_colsher_radial=0.5F, const int stretch_factor_axial=2, const int stretch_factor_planar=2)
	constructor for the ColsherFilter. More...

Succeeded	set_up (int height, int width, float theta, float d_a, float d_b)
	Initialise filter values. More...

virtual std::string	parameter_info () const

Public Member Functions inherited from stir::ArrayFilterUsingRealDFTWithPadding< 2, float >
	ArrayFilterUsingRealDFTWithPadding ()
	Default constructor (trivial kernel)

	ArrayFilterUsingRealDFTWithPadding (const Array< num_dimensions, float > &real_filter_kernel)
	Construct the filter given the real kernel coefficients. More...

	ArrayFilterUsingRealDFTWithPadding (const Array< num_dimensions, std::complex< float >> &kernel_in_frequency_space)
	Construct the filter given the complex kernel coefficients. More...

Succeeded	set_kernel (const Array< num_dimensions, float > &real_filter_kernel)
	set the real kernel coefficients

Succeeded	set_kernel_in_frequency_space (const Array< num_dimensions, std::complex< float >> &kernel_in_frequency_space)
	set the complex kernel coefficients

bool	is_trivial () const override
	checks if the kernel corresponds to a trivial filter operation More...

Public Member Functions inherited from stir::ArrayFunctionObject_2ArgumentImplementation< num_dimensions, float >
void	operator() (Array< num_dimensions, float > &array) const override
	in-place modification of array, implemented inline

void	operator() (Array< num_dimensions, float > &out_array, const Array< num_dimensions, float > &in_array) const override
	result stored in another array More...

Public Member Functions inherited from stir::ArrayFunctionObject< num_dimensions, float >
virtual Succeeded	get_influencing_indices (IndexRange< num_dimensions > &influencing_indices, const IndexRange< num_dimensions > &output_indices) const
	sets the range of indices that influences the result in a set of coordinates output_indices More...

virtual Succeeded	get_influenced_indices (IndexRange< num_dimensions > &influenced_indices, const IndexRange< num_dimensions > &input_indices) const
	sets the range of indices that gets influenced by a set of coordinate input_indices More...

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)

Additional Inherited Members
Protected Member Functions inherited from stir::ArrayFilterUsingRealDFTWithPadding< 2, float >
void	do_it (Array< num_dimensions, float > &out_array, const Array< num_dimensions, float > &in_array) const override
	Performs the convolution. More...

Protected Attributes inherited from stir::ArrayFilterUsingRealDFTWithPadding< 2, float >
Array< num_dimensions, std::complex< float > >	kernel_in_frequency_space

Detailed Description

This class contains the Colsher filter used for 3D-PET reconstruction.

The Colsher filter is combined with a 2-dimensional apodising Hamming filter.

Constructor & Destructor Documentation

◆ ColsherFilter() [1/2]

stir::ColsherFilter::ColsherFilter ( )

inline

Default constructor.

Warning: Leaves object in ill-defined state

Referenced by set_up().

◆ ColsherFilter() [2/2]

stir::ColsherFilter::ColsherFilter	(	float	theta_max,
		float	alpha_colsher_axial = `1.F`,
		float	fc_colsher_axial = `0.5F`,
		float	alpha_colsher_radial = `1.F`,
		float	fc_colsher_radial = `0.5F`,
		const int	stretch_factor_axial = `2`,
		const int	stretch_factor_planar = `2`
	)

explicit

constructor for the ColsherFilter.

Parameters

theta_max the polar angle corresponding to the maximum oblique angle included in the reconstruction.

The alpha and fc parameters are designed to minimize the amplification of noise.

The stretch_factor parameters can be used to define the Colsher filter via a finer grid to avoid the problems with sampling a continuous filter in frequency space. For the ramp-filter, this can be done using analytic integration, but here we have to do it numerically.

Member Function Documentation

◆ set_up()

Succeeded stir::ColsherFilter::set_up	(	int	height,
		int	width,
		float	theta,
		float	d_a,
		float	d_b
	)

Initialise filter values.

creates a 2D Colsher filter of size height*width,