The block-optimal realization of separable-in-denominator 2-D digital filters

The optimal synthesis of a single input single output separable-in-denominator 2-D digital filter with fixed-point arithmetic is investigated. In the first phase, a general partial fraction expansion for this class of filter is presented. In sequel, a parallel block-optimal realization is proposed in order to minimize the round-off noise under L2 scaling. A novel criterion for the absence of limit cycle of second order block-optimal structure is also derived. A numerical example is provided to illustrate the effectiveness of the proposed method.