Abstract

The main objective of this Thesis has been to implement two-dimensional filter functions using simple design procedures and to study the presence of circular symmetry in such designed filters by parameter modifications. In keeping with the simple design criteria, the two-dimensional filters studied in this thesis have been designed starting from two one-dimensional filters as an independent product. Only IIR Filters have been considered for this purpose due to their capability of approximating the required response with low order filters and also their flexibility in terms of altering filter parameters to obtain new filters. The filters have been checked for stability before analysis. The design has made use of the fact that varying the feedback factor "k" in an IIR filter produces a near-circular symmetric response for certain values of "k" between specific magnitude ranges. Algorithms have been obtained to check the extent of circular symmetry under specific magnitude ranges and to correct the feedback factor "k" in order to obtain the maximum proximity to circular symmetry