Two-dimensional two channel FIR signal adapted filter banks

In this paper the optimality results of two-dimensional, two-channel filter banks for different subsampling matrices were compared. It is seen that quincunx matrix is optimum in most of the natural images and also quincunx filter bank is a good match to the human visual system. A sub-optimal solution was also proposed that extends one-dimensional signal adapted filter bank design procedure to two-dimensional(2D) nonseparable FIR signal adapted filter banks using quincunx subsampling matrix. A cascade structure is used for the factorization of 2D paraunitary polyphase matrix and simulation of the nonseparable filter bank is done using iterative greedy algorithm. The simulated FIR responses match the ideal responses very closely