Abstract

Median filters are widely used in image processing because they remove impulsive noise while preserving edges. They are one example of a class of filter known as order statistic filters which require a ranking of pixels within the filter window. When only one of the ordered pixels (the i th pixel) is then selected as the output of the filter, the result is called the i th ranked-order operation. The median filter of window size N is therefore an (N + 1)/2 ranked-order operation while the maximum and minimum filters are, respectively, Nth and 1st ranked-order operations.

© 1986 Optical Society of America