Mathematical morphology on the sphere
J.B.T.M. Roerdink. Mathematical morphology on the sphere. Proc. SPIE Conf. Visual Communications and Image Processing '90, Lausanne, 1990, pp. 263-271.
In this paper we show how the classical morphological definitions for Euclidean space can be extended to the sphere, where the rotation group replaces the Euclidean translation group. The main problem to overcome is the non-commutativity of the rotation group. Some examples of morphological transformations on the sphere are given. To visualize the results we use a projection of the sphere onto a plane.