ABSTRACT
Qjj (na) = a x fFFT{FFT[Pp' (na)withZP ]x FFT[h(na)withZPIx [S/1100fhing WindOW]} (4)
When implemented within the frequency domain this smoothing filter may be expressed as a simple cosine function or a Hamming window: In the present case, a Hamming window function have been chosen for the smoothing process:
wen) = 0.54 + 0.46 cos(2mz! V) (5)
The outer integral in cquation 9 prcscnts a weighted back-projection operation. Each filtered projection is smcarcd back to the image plane along fan beam. Thc sum of all the projections is us cd to producc thc image of the object since,
In practice, if the value of r' calculated with (8) does not corrcspond to one of angles for which projection data is known, then interpolation is needed, although in the present case linear interpolation is sufficient.
