A weighted lattice structure for 2-D denominator-separable digital filters

2-D denominator-separable digital filters represent an important subclass of 2-D recursive digital filters. Various implementations have been suggested. In this paper, to derive new realizations the fact is used that, different from the case of a general 2-D digital filter, a denominator-separable filter can be developed as an orthonormal expansion. The orthonormal basis has been chosen such that the components can be realized by a normalized lattice structure, proposed in the 1-D case by Gray and Markel (1975). The new realization inherits all properties of the normalized lattice structure: low roundoff noise, freedom from overflow limit cycles