Sorting Network Based Architectures for Median Filters

This paper presents sorting network based architectures for computing non-recursive and recursive median lters. The proposed architectures are highly pipelined, and consist of fewer compare-swap units than existing architectures. The reduction in the number of compare-swap units is achieved by minimizing computational overlap between successive outputs, and also by using Batcher's odd-even merge sort (instead of bubble-sort). The latency of these networks is reduced by building them with sorting units that sort 2 elements (sort-2) as well as 3 elements (sort-3) in 1 time unit.