Two-dimensional linear phase cosine modulated filter banks

A filter bank is referred to as cosine modulated when all the analysis and synthesis filters are cosine modulated versions of one or two prototypes. The one-dimensional (1D) cosine modulated filter bank (CMFB) is well-known for low design cost and low complexity. In the application of subband coding, it is sometimes desirable that the individual filters have linear phase. In this paper, we consider the class of 2D paraunitary CMFB with FIR linear phase filters. Necessary and sufficient conditions for perfect reconstruction of the 2D linear phase CMFB are presented.