Patent ID: 7590268

Claim:
A method for representing an area of a raster image by a centerline, the method comprising: using a computer to 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; 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.