Method for the impulsive noise detection and its application for the improvement of the impulsive noise filtering algorithms

摘要

A new approach to impulsive noise filtering is considered in the paper. It is known that the median filter is a sliding window filter, with a window N x N. As it is known, the impulsive noise is a "big" and unusual jump of brightness. So if the central pixel in the window is noisy, its value belongs to one of the ends of the variation representation of the local histogram. We analyze, where the value of central pixel of the window is positioned in the variation series. If it is positioned close to the boarders, we can assume that it is an impulsive corruption and it must be filtered. This kind of analysis could be used for the improvement of many filters: median, rank-order, cellular neural, etc. So, implementing such kind of preliminary noise detection, we achieve the good results. Filters became gentler and less destructive for the image, but steel very effective.