Wavelet transform on manifolds: old and new approaches
Given a two-dimensional smooth manifold M and a bijective pro jection p from M on a ﬁxed plane (or a subset of that plane), we explore systematically how a wavelet transform (WT) on M may be generated from a plane WT by the inverse projection. Examples where the projection maps the whole manifold onto a plane include the two-sphere, the upper sheet of the two-sheeted hyperboloid and the paraboloid. When no such global pro jection is available, the construction may be performed locally, i.e., around a given point on M. We apply this procedure both to the Continuous WT, already treated in the literature, and to the Discrete WT. Finally, we discuss the case of a WT on a graph, for instance, the graph deﬁned by linking the elements of a discrete set of points on the manifold.