Median Filtering of Video Signals — A Powerful Alternative
This article describes a novel filtering technique to free video signals from interfering signals. In contrast to the procedures based on recursive or transversal digital filter structures, a nonlinear technique is introduced with the median filtering. Nonlinearities in the course of a signal-processing chain produce distortions, harmonic waves, aliasing, and other defects that seem to render the application of the median filtering of video signals unsuitable. A three-dimensional median filter utilizing the statical linkages of picture elements with regard to space and time is suitable for filtering a video signal without visible artifacts appearing in the picture. The median filter thereby eliminates almost all interferences in the video signal. Picture elements disturbed by noise are replaced by a nearby picture element that is less disturbed. The median filtering is also an effective procedure for such other statical disturbances as bit errors or dropouts. Even regular interference structures such as cross color and cross luminance can be suppressed by special design of the filter window.
- Print ISSN
- 0036-1682
- Published
- 1991-07
- Content type
- Original Research
- DOI
- 10.5594/J08966