2-D causal recursive digital filter modeling implementation

A technique is proposed to find the causal recursive filter model that realizes a given impulse response support. This is shown to be an essential step in any design problem. Although, the local state space (LSS) is used throughout the paper to represent the filter model, all results apply as well to the transfer function representation. Several aspects of the implementation problem which are dependent on the choice of the filter model are also discussed. These are the recursion sequence, the implementation storage and the possible parallelism in calculating the output samples.