COMPUTER PROCESSING OF RI IMAGES BY USE OF LOW-PASS FILTERS (I) : LOW-PASS DIGITAL FILTER SYNTHESIS

Abstract

On condition that MTF of filter had circular symmetry, seven low-pass digital filters, which covered a wide range of cutoff frequencies from 3.2/64 to 23.6/64 cycles/sample, were synthesized by using Fourier-Bessel transform. These filters were applied to 64×64 matrix image from a scintillation camera and then Fourier spectra of the processed images were computed. As a result of the spectral analysis the fact was verified that for allthe synthesized filter characteristics the spectrum components were zero over the stopbands and underwent almost no change over the passbands.