Two-dimensional recursive digital filtering: Pipelining, one- and two-dimensional block processing

Unlike one-dimensional recursive systems, two-dimensional recursive digital filter algorithms for pipelining and/or parallelism. The locus of these concurrent computations is referred to as the concurrent computation region. The authors describe the use of this concurrency to derive pipelined and one-dimensional block architecture for implementation of two-dimensional recursive digital filters by appropriate interleaving (or indexing) of the input samples, without requiring any algorithm transformation and without any hardware overhead. They also derive a two-dimensional incremental block filter using look-ahead computation and incremental computation techniques. Pipelined two-dimensional block structures and the index mapping functions for various architectures are presented. Finally, it is shown that for an N-dimensional recursive filter, the concurrent computation region corresponds to an (N-1)-dimensional hyperplane.