Fast median‐finding word comparator array

Finding the median of a set of data within a window of finite size is computationally challenging on account of the complexity in sorting. Compared with the established nine‐stage systolic arrays, an eight‐stage systolic array to find the median of a fixed 3 × 3 window of n bit integers is proposed. The proposed array requires a fewer number of signal paths, and is faster for fixed resource. The method employed uses selective comparators for finding the median by avoiding comparators required to obtain fully sorted list. This reduces the partial sorting to eight‐stage systolic array. However, this is applicable only to median sorting of 3 × 3 fixed window. The method employs combinatorial circuit implementation; consequently there is 12% gain in speed and 7% fewer signal paths. Circuit with memory cells at every stage and eight latency cycles results in 36% speed gain over the state‐of‐the‐art non‐sorting based methods. This method provides superior performance in comparison with the methods available for fixed 3 × 3 window‐based median filters.