Design of an Area-Efficient One-Dimensional Median Filter

An area-efficient 1-D median filter based on the sorting network is presented in this brief. It is a word-level filter, storing the samples in the window in descending order according to their values. When a sample enters the window, the oldest sample is removed, and the new sample is inserted in an appropriate position to preserve the sorting of samples. To increase the throughput, the deletion and insertion of samples are performed in one clock cycle, so that the median output is generated at each cycle. The experimental results have shown the improved area efficiency of our design in comparison with previous work.