Convert parallel-beam projections to fan-beam
converts the parallel-beam data F
= para2fan(P
,D
)P
to the fan-beam data
F
. Each column of P
contains the parallel-beam
sensor samples at one rotation angle. D
is the distance from the fan-beam
vertex to the center of rotation.
The parallel-beam sensors are assumed to have a one-pixel spacing. The parallel-beam rotation angles are spaced equally to cover [0,180] degrees. The calculated fan-beam rotation angles have the same spacing as the parallel-beam rotation angles, and cover [0,360) degrees. The calculated fan-beam angles are equally spaced with the spacing set to the smallest angle implied by the sensor spacing.
uses name-value pairs to control aspects of the data conversion.F
= fan2para(P
,D
,Name,Value
)
[
returns the fan-beam sensor locations in F
,fan_sensor_positions
,fan_rotation_angles
]
= fan2para(___)fan_sensor_positions
and
rotation angles in fan_rotation_angles
.