Centers of sets of pixels

TitleCenters of sets of pixels
Publication TypeJournal Articles
Year of Publication2000
AuthorsKhuller S, Rosenfeld A, Wu A
JournalDiscrete Applied Mathematics
Pagination297 - 306
Date Published2000/07/15/
ISBN Number0166-218X
KeywordsCenter, Chessboard distance, City block distance, Intrinsic distance, Simply connected set

The center of a connected graph G is the set of nodes of G for which the maximum distance to any other node of G is as small as possible. If G is a simply connected set of lattice points (“pixels”) with graph structure defined by 4-neighbor adjacency, we show that the center of G is either a 2×2 square block, a diagonal staircase, or a (dotted) diagonal line with no gaps.