Convexity-Preserving Rigid Motions of 2D Digital Objects

Rigid motions on R-2 are isometric and thus preserve the geometry and topology of objects. However, this important property is generally lost when considering digital objects defined on Z(2), due to the digitization process from R-2 to Z(2). In this article, we focus on the convexity property of digital objects, and propose an approach for rigid motions of digital objects which preserves this convexity. The method is extended to non-convex objects, based on the concavity tree representation.