Design of low-delay perfect-reconstruction FIR filter banks for tree-structured subband coders

Two methods for the design of two-channel perfect reconstruction FIR filter banks with short reconstruction delays are presented. The first method is based on the Lagrange-multiplier method. The method is simple, efficient, flexible, and leads to a closed-form exact solution. The second method is based on a quadratic-constrained least-squares minimization. Design examples are given to illustrate the advantages of the proposed methods. The quality of reconstruction is considered very good and superior to those of existing methods