A fast and accurate multilevel inversion of the radon transform

A number of imaging technologies reconstruct an image function from its Rad on projection using the convolution backprojection method. The convolution is an O(N-2 log N) algorithm, where the image consists of N x N pixels, whi le the backprojection is an O(N-3) algorithm, thus constituting the major c omputational burden of the convolution backprojection method. An O(N-2 log N) multilevel backprojection method is presented here. When implemented wit h a Fourier-domain postprocessing technique, also presented here, the resul ting image quality is similar or superior to the image quality of the class ical backprojection technique.