Patent ID: 7576754

Claim:
A computer-implemented method of identifying boundaries of a geographic area comprising a city, the method comprising: (a) identifying coordinates of multiple cities; (b) associating with each city a grid of cells of geographic data encompassing the city's coordinates; (c) for each cell associated with a city, identifying a larger replacement cell of geographic data encompassing the cell; (d) testing for intersection between replacement cells of cells of different cities; (e) for each cell whose replacement cell does not intersect another replacement cell of another cell of another city, replacing the cell with the replacement cell and associating the replacement cell with the city; (f) repeating (c)-(e) to replace replacement cells with further replacement cells until: (1) no cell associated with a city can be replaced without the replacement cell intersecting a replacement cell associated with a different city; or (2) said (e) has been performed a threshold number of times; or (3) an area covered by cells associated with the city meets a threshold size; and (g) using said replacement cells to define a boundary of the geographic area; wherein the method is implemented in a computer system that comprises a process and a memory.