Optimization of 2D median filtering algorithm for VLIW architecture
Chang Y. Choo, Ming Tang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1999
Recently, several commercial DSP processors with VLIW (Very Long Instruction Word) architecture were introduced. The VLIW architectures offer high performance over a wide range of multimedia applications that require parallel processing. In this paper, we implement an efficient 2D median filter for VLIW architecture, particularly for Texas Instrument C62x VLIW architecture. Median filter is widely used for filtering the impulse noise while preserving edges in still images and video. The efficient median filtering requires fast sorting. The sorting algorithms were optimized using software pipelining and loop unrolling to maximize the use of the available functional units while meeting the data dependency constraints. The paper describes and lists the optimized source code for the 3 X 3 median filter using an enhanced selection sort algorithm.