Comments on "Theoretical analysis of the max/median filter" by G.R. Arce and M. P. McLaughlin

In the original paper (ibid., vol.ASSP-35, no.1, p.60-9, Jan. 1987), an approach (the max/median filter) to remove noise from images without distorting geometrical information was introduced. The proposed filter structure, due to its asymmetrical nature, is able to preserve only the subtle signal structures that are larger in intensity than the local background level. The commenters suggest another filter structure that has the ability to preserve both positive and negative geometrical information with respect to the background level.>