Concurrent architectures for two-dimensional recursive digital filtering

Efficient architectures are presented for high-speed implementation of two-dimensional recursive digital filters of direct form and local state-space form. Unlike one-dimensional recursive systems, two-dimensional recursive digital filter algorithms have a large amount of inherent concurrency. The authors exploit this concurrency to derive fine-grain pipelined and one-dimensional block architectures 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 then extend the look-ahead computation and incremental computation techniques to two dimensions and use them to derive two-dimensional incremental block filter architectures. The multiplication complexity of the two-dimensional incremental block filter is determined.