Resolution Improvement to C.T.Systems Using Aperture Function Correction

One of the fundamental limitations to the resolving power of a C.T. scanner is the image degradation introduced by sampling the data with source/detector combinations of finite size. In this paper we investigate the effect of this degradation on the measured projections and the reconstructed image, and relate it to effects due to the discrete sampling of the signal. Having identified the transfer function of the imaging system, it is then possible to formulate filtering techniques which attempt to restore the image to its desired form. We derive a frequency domain Wiener filter, which when applied to our C.T. data attempts to restore those frequency components attenuated in the scanning process.