Corners

• A is an upper-left corner region if (i+1, j)?A or (i, j+1)?A => (i, j)?A

• Notation: F is the complement of F.

LEMMA: (Chrobak, Dürr 1998, Kuba 1999)

F is an hv-convex 4- or 8-connected discrete set iff

F = A ? B ? C ? D, where A, B, C, D are

disjoint corner regions.

Previous slide

Next slide

Back to first slide

View graphic version