Patent ID: 7133551

Claim:
A method for semi-automatically reconstructing 3-D building models, comprising: using a plurality of building outline segments to construct a plurality of closed polygonal building boundaries, wherein the neighboring building outline segments are either connected or disconnected; creating an initial building model; performing a pre-processing process on the building outline segments; successively splitting the initial building model by the building outline segments to generate a plurality of the 3-D building models; removing the 3-D building models that are connected to the initial building model; successively analyzing shared boundaries of the two connected 3-D building models whether or not having a corresponding one of the building outline segments; if no corresponding building outline segment exists, then merging the two building models into one single building model; if one corresponding building outline segment exists, then keeping the two building models as the 3-D building models; assigning a height to every one of the building's boundaries according to a height of the corresponding one of the building outline segments; and successively analyzing whether each of the building model's boundaries is an independent-edge or a shared-edge, wherein the independent-edge means that it does not overlapped with the other building model's boundaries on a 2-D horizontal plane, and the height information for the independent-edge can then be assigned and fixed from the corresponding one of the building outline segments, wherein if only one of the independent-edges is found, it is necessary to check whether its surrounding rooftop is fixed or not; wherein if all of its surrounding rooftop have already been fixed, then its rooftop can be inferred from the independent-edge; and if at least two of the independent-edges exist and are sufficient to fit into a planar face, then a least-squares coplanar fitting can be applied, otherwise, a most possible solution is provided by a consecutive-coplanar analysis.