3d Architectural Modeling From Photo Collections

Digital City has become the new term after the Internet. More and More people pay close attention to it. Three-dimensional digital city modeling is the most basic problem in the Digital City. It provides a very effective way to the city management and urban construction. Today, the digital city model mainly divided into several ways. First, the Geometric modeling approach. The method uses professional modeling software, such as MAYA,3DsMAX, AutoCAD, etc. Second, using sophisticated equipment acquire the point cloud of architecture to modeling. Third, based on photo sequence or video to modeling. It uses computer vision technology. In recent years, more and more people pay close attention to the third method, because of its low cost and fast modeling advantage. We make an interactive modeling system bases on the third method to build the the 3D architecture model. This system can produce the photorealistic 3D architecture model from the unordered photo collections.First, the system relies on accurate knowledge of camera orientation and sparse 3D geometry estimated from the observed scene. It starts by pre-processing all the photographs. Take advantage of SIFT feature points to match between two images. Then through the method of solving fundamental matrix to find epipolar geometry feature points. Last, performing structure from motion analysis to recover the 3D point cloud and camera orientation.Second, after performing the pre-processing stage, the user can draws outlines overlaid on 2D photographs. The system can generate piece wise-planar 3D models of architectural structures after using 3D point cloud and camera information. And then interactive select a particular planar segment to edit its geometry, such as welding planes, Editing the plane boundary, Fillet planes and Extrusions. After these operation, the geometric modeling of building structure can be generated. Last, choosing the pixel from the most frontal view for each texel independently for texture mapping to generate photorealistic architectural model.At the end of this paper, several examples of architecture model reconstruction are given, to show that using our system to reconstruct buildings model effectiveness and usability.