Semi-automatic reconstruction method of 3-D building models using building outline segments

1. 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.

2. The method according to claim 1 , wherein the method further comprises acquiring a plurality of stereo images of the building model from different positions to perform the reconstruction of the building models, wherein the building outline segments are obtained by a stereo-measurement from roof edges of the building model.

3. The method according to claim 1 , wherein the building outline segments includes three kinds of data, which are (i) a building layer of a digital topographic map in a form of the building outline segments, (ii) partial-occluded the building outline segments, and (iii) a 2-D building outline vector together with a number of stories and a terrain height information.

4. The method according to claim 1 , wherein when dealing with ground objects that have a character of closed polygon, the method can integrate the digital photogrammnetric mapping wit the 3-D building model reconstruction to reduce a task of manual editing and manual modeling.

5. The method according to claim 1 , wherein when a 2-D building outline vector together with a number of stories and a terrain height information are utilized, a height of a flat-roof can be derived from the number of stories and the terrain height.

6. The method according to claim 1 , wherein the pre-processing comprises:

performing collinear processing, dangle removal, or dangle snapping when the building's structure is not rectangular; and

performing orthogonal processing, collinear processing, dangle removal, or dangle snapping when the building's structure is rectangular.

7. The method according to claim 1 , further comprising performing a visual inspection and post-processing, which comprises:

inspecting whether each of the 3-D building models is fit with the corresponding the building outline segments and consistent with the building in original aerial stereo-images;

if topology errors occurred due to manual measurement mistakes, an operator returning to the manual stereo-measurement stage to correct these mistakes and redo the modeling procedure;

if topology errors occurred due to stereo-measurement errors, the operator applying a suitable pre-processing procedure to automatically adjust the building outline segments and redo the modeling procedure;

if shaping errors occurred due to non-coplanarity of the roof-edges measurements, the operator choosing the best-fit rooftop provided by the consecutive-coplanar analysis; and

if a topology and a roof shape are all right, keeping the building models and forming a polyhedral building model.

8. The method according to claim 1 , further comprising a semi-automatic method for producing a prismatic building model:

according to an ownership information, interactively selecting the 3-D building models that belong to a same owner;

merging the selected 3-D building models into a single building model automatically-, and

giving a flat roof and an actual height to form the prismatic building model automatically.

9. The method according to claim 8 , further comprising a visual inspection procedure, which comprises

inspecting whether the actual height of the generated prismatic building model is correct;

if not, interactively choosing a correct one from all possible one of the roof heights provided by heights of a polyhedral building model; and

if yes, forming the prismatic building model.