Multi-level three-dimensional building modeling by integration of aerial and ground view images

Accurate 3D building models of a city are useful for a variety of applications such as 2D and 3D GIS, fly-through rendering, and simulation for mission planning. Each application may require different aspects of the model. Different levels of information are computed from different data sources. For example, information such as the roof boundary or building height can be obtained by using aerial images or LIDAR (LIght Detection And Ranging) data. Facade information, such as its texture or detailed 3D structure, can be computed from multiple ground view images.; In this thesis, acquisition processes for the different levels of building model from various data sources are integrated by deriving a multi-level representation of 3D building model. The concept of Level Of Detail (LOD) from virtual reality literature is exploited to represent the different levels of knowledge for the 3D building model. The multi-level representations of the 3D building model are defined as followings: Level 1 (Initial 3D building) model, Level 2 (Building facade texture) model, and Level 3 (Detailed facade structure) model.; The reconstruction process of more complex level models is aided by simpler level models. The knowledge that building roof is parallel to the ground and its wall is perpendicular to the ground, is used to obtain Level 1 model (simpler model). 3D information of Level I model such as its 3D vertices, boundary lines, and facade faces can be used to estimate the pose of uncalibrated ground view images to acquire Level 2 model (facade texture). The calibrated ground view information from Level 2 and 3D model information from Level 1 are used to reduce user interactions in creating Level 3 model, which capture detailed facade structures such as entry ways, recesses, or window structures. Complex and large area site modeling tasks can be done more efficiently by integrating multiple data sources. The final result is a rich multi-level 3D model useful for a variety of applications depending on their needs.