Design of two‐dimensional pseudolossless digital filters with prescribed spatial responses

Abstract

The paper presents a technique to compute the parameters of the state-space model of the two-dimensional pseudolossless (e.g. wave or orthogonal) digital filter that best approximates a given spatial response. The search for the optimal solution is performed using an unconstrained optimization algorithm with reduced number of parameters. The optimization variables are the elements of the upper triangle of a skew-symmetric matrix which is related to the orthogonal system matrix by the Cayley formula. Thus the resulting system is always stable.