The class of nonlinear filters known as order statistic filters has been successfully applied for the restoration of images, overcoming difficulties not solvable by the use of linear filters. An adaptive approach for the restoration of images using OS filters was proposed by Restrepo and Bovik (1988); it makes use of a moving quasi-range filter for the estimation of edges. We explore further this type of filter for edge detection.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
