Design of two-dimensional IIR digital filters with linear phase

Digital Spectral Transformation (DST) has been used to approximate the magnitude response specifications of circular, elliptic and fan shaped filters. In this paper, it is shown that when the DST proposed by Harn and Shenoi (1986) is applied to the 1D lowpass prototype filters with linear phase characteristics to realize 2D IIR filters, it preserves both magnitude and phase characteristics in the /spl omega//sub 1/-/spl omega//sub 2/ plane. Several attractive features of using this approach are discussed and simulation results are provided to illustrate its performance.<
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