Convert fanbeam projections to parallelbeam
P = fan2para(F,D)
P = fan2para(..., param1, val1, param2,
val2,...)
[P ,parallel_locations, parallel_rotation_angles]
= fan2para(...)
P = fan2para(F,D)
converts
the fanbeam data F
to the parallelbeam data P
. D
is
the distance in pixels from the fanbeam vertex to the center of rotation
that was used to obtain the projections.
P = fan2para(..., param1, val1, param2,
val2,...)
specifies parameters that control various aspects
of the fan2para
conversion, listed in the following
table. Parameter names can be abbreviated, and case does not matter.
Parameter  Description 

 Range through which the beams are rotated, specified as one of the following:

 Positive real scalar specifying the increment of the rotation angle of the fanbeam projections, measured in degrees. Default value is 1. 
 Positioning of sensors, specified as one of the following:
See 
 Positive real scalar specifying the spacing of the fanbeam
sensors. Interpretation of the value depends on the setting of If If NoteThis linear spacing is measured on the x' axis.
The x' axis for each column, 
 Type of interpolation used between the parallelbeam and fanbeam data, specified as one of the following:.

 Range of rotation, specified as one of the following:

 Positive real scalar specifying the parallelbeam rotation
angle increment, measured in degrees. Parallel beam angles are calculated
to cover [0,180) degrees with increment If 
 Positive real scalar specifying the spacing of the parallelbeam sensors in pixels. The range of sensor locations is implied by the range of fan angles and is given by [D*sin(min(FAN_ANGLES)),... D*sin(max(FAN_ANGLES))] If 
[P ,parallel_locations, parallel_rotation_angles]
= fan2para(...)
returns the parallelbeam sensor locations
in parallel_locations
and rotation angles in parallel_rotation_angles
.
The input arguments, F
and D
,
can be double
or single
, and
they must be nonsparse. All other numeric inputs are double
.
The output P
is double
.