“…without violating the causality principle [136]. As such, one can apply to LOIs the whole machinery of techniques that has been developed in the context of scale-space research, such as the N-jet for local image structure description [137,70,94], the construction of invariants and (oriented) filter families [138,139,140,71], non-linear diffusion schemes [195,93], scale selection methods [160,161], etc.…”