Median filtering is a nonlinear filtering technique which is known for preserving sharp changes in signals and being particularly effective in removing impulse noise. It is very widely used in speech and image processing since it was first described by Tukey. Recently, Neuvo first introduced the concepts of vector median. In this approach, the samples of the vector- value input signals are processed as vectors instead of componentwise scalar processing. The vector median utilizes the correlation between different components. Thus, it is good for HDTV color image processing. In this paper, we first discuss the difference between componentwise median filter and vector median filter. Then, we propose several new vector median filters to increase signal noise ratio. A fast computational architecture for these algorithms is also addressed.
J. S. Lee,
"New hardware implementation of fast vector median filters", Proc. SPIE 2094, Visual Communications and Image Processing '93, (22 October 1993); doi: 10.1117/12.157978; https://doi.org/10.1117/12.157978