Approximation design of 2-D digital filters with elliptical magnitude response of arbitrary orientation
This paper presents an approximation technique which resuits in simple formulas for fast calculation of the McClellan transform coefficients, and should be useful for real-time and adaptive 2-D digital filtering. The coefficients are calculated by fitting the power series expansion of the transform to the analytical description of the iso-potential contours of the filter. Formulas are also derived for the coefficients of the scaling-free transform, recently proposed by the authors.