Reduction of artifacts by digital filtering in Fourier image reconstruction

The use of digital filtering is explored as a means of minimizing artifacts in a general class of image reconstruction approaches commonly referred to as direct Fourier reconstruction methods. In the polar-to-Cartesian conversion, applications of windowing operations for the two-dimensional interpolation-type methods are seen to reduce artifacts according to a number of error measures. For the one-dimensional case, the use of a high-resolution spline interpolation gives the lowest error measures. The use of the chip-Z transform is proposed as a way to generate transformed projection data in a concentric square grid to eliminate part of the one-dimensional interpolation currently needed for the processing