Patent ID: 7876932

Claim:
A system, comprising: a processor; and a storage device storing program instructions that when executed by the processor perform: receiving a planar map which represents a raster image that contains a region, wherein a face in the planar map maps to the region in the raster image, and wherein the edges of the face map to the boundary of the region; selecting as a subregion of the region a portion of the region whose width, as measured across the region from one boundary point to another boundary point, does not exceed a maximum-width threshold, wherein both the subregion and a portion of the region outside the subregion are currently represented by an outline comprising the edges of the face; determining a centerline for the subregion, wherein the centerline coincides with at least a portion of a medial axis of the region; and transforming the planar map so that the subregion is represented by the centerline, and so that the portion of the region outside the subregion is represented by an outline comprising a portion of the edges of the face.