Order reduction of 2-D FIR filters with applications

The author develops two algorithms for the order reduction of two-dimensional (2-D) FIR digital filters, which lead to two indirect design methods. Specifically, it is shown how an optimal L/sub 2/ design can be derived as a matrix approximation problem in the Frohenius norm, and how a suboptimal L/sub /spl infin// design can he obtained by solving a matrix approximation problem in the 2-norm using the Davis-Kahan-Weinberger theorem on norm-preserving dilations. A case study is included to demonstrate the usefulness of the proposed methods.