A novel approach to the design of 2-d recursive digital filters

✍ Scribed by A. Mazinani; M. Ahmadi; M. Shridhar; R.S. Lashkari

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 361 KB
• Volume: 329
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/0016-0032(92)90102-m

✦ Synopsis

An eficient method is presented for the design of 2-D circular symmetric recursive digital filters satisfying prescribed magnitude and constant group-delay responses. The transfer function of this class of 2-D filters has a zero-phase non-separable numerator and separable denominator 2-variable polynomials in z, and z 2. In the proposed technique the coeficients of the 2-Dhlters are calculated in two steps. In the first step the parameters of two I-D all pole filters l/D, (z,) and I/D,(z,) are calculated by minimizing a multicriterion objective function using a suitable optimization technique so that the magnitude and groupdelay responses of the desired 2-Dfilter along the o,, wz axes are obtained. Essentially, the first step of the proposed design method yields a 2-D all pole separable product filter with rectangular cutoff boundaries with or without constant group-delay responses in the passband of the above filter. In the second step, the parameters of the zero-phase 2-variable nonseparable polynomial in z, and z2 in the numerator can be determined through minimization of a cost function using a linear programming approach. Note that the second step acts as a magnitude equalizer to convert a rectangular cutoff boundary to a circular one. An example illustrates the usefulness of the proposed algorithm.