Deriving the Medial Axis with geometrical arguments for planar shapes

In this paper a novel method to derive the Medial Axis of a shape is presented. The property that the Medial Axis is a subset of the Symmetry Set is used. The latter allows a formulation in terms of two equations, based on geometrical arguments. From the set that solves the equations, the subset that yields the Medial Axis can be taken. An algorithm is given that performs these tasks. The Medial Axis can easily be labelled with respect to main axis and branches, as this information follows directly from the Symmetry Set.