A simple lattice architecture for even-order linear phase perfect reconstruction filter banks

A simplified lattice architecture is given for 2-channel perfect reconstruction multirate filter banks when the filters are even-order linear phase FIR filters. This approach provides a factorization procedure for the type-1 polyphase component matrix, E(z), for the analysis filter bank. The architecture used ensures that the perfect reconstruction property is structurally imposed by the mathematical form of the factorization. An application is given to the factorization of the filter bank employed in the FBI´s standard for digital coding of fingerprint images, and comparisons are made with previous lattice architectures for even-order linear phase filters