A general-purpose optimization technique for designing two-channel FIR filter banks

An efficient general-purpose optimization algorithm is proposed for designing two-channel FIR filter banks. This technique can be used for optimizing two-channel FIR filters in all the alias-free cases proposed in the literature. The generalized problem is to minimize the maximum of the stopband energies of the two analysis filters subject to the given passband and transition band constraints and the given allowable reconstruction error. Therefore, in addition to the perfect-reconstruction filter banks, nearly perfect-reconstruction banks can be optimized in a controlled manner. The optimization is carried out in two steps. In the first step, a good starting-point filter banks for further optimization is generated using an existing design scheme for the selected class of filter banks. The second step involves optimizing the filter bank with the aid of the proposed algorithm. Several examples are included illustrating the efficiency of the proposed approach.