Frequency-domain design of 2-D digital filters using the iterative singular value decomposition

The authors propose a technique for designing 2-D digital filters (2DDFs) with specified magnitude and constant group delay characteristics. The method is based on the iterative singular value decomposition (ISVD) of a 2-D magnitude specification matrix. The ISVD guarantees all its decomposition results to be always nonnegative. By using the ISVD, 2-D magnitude specifications can be decomposed into a pair of 1-D ones, and thus the problem of designing a 2DDF can be reduced to the one of designing a pair of 1DDFs or even only one 1DDF. A design example shows that this technique can be used to design 2DDFs with a higher degree of precision but needs less computational effort