An alternative algorithm for adaptive histogram equalization

Adaptive histogram equalization has become well-established as a technique for enhancing contrast in images. This paper investigates an alternative formulation of histogram equalization. An implementation of this is presented. The resulting algorithm involves the application of a filter to a set of image fields, and the potential for filtering these fields differently is illustrated through the restoration of a deliberately degraded image, Hence the alternative algorithm is shown to be effective and to provide a framework for improved estimation of the optimal gray-level mappings over standard methods. (C) 1996 Academic Press, Inc.