Effective Impulse Detector Based on Rank-Order Criteria

A new impulsive noise detection technique is presented here. Preserving edges and details in the process of impulsive noise filtering is an important problem. To avoid image smoothing, only corrupted pixels must be filtered. In order to identify the corrupted pixels, a new impulse detector is proposed. This detector is based on a comparison of signal samples within a narrow rank window by both rank and absolute value. It is efficient, very fast, and can be used with any filter (even iteratively), without smoothing an image.