Coplanar Shadowgrams for Acquiring Visual Hulls of Intricate Objects

Acquiring 3D models of intricate objects (like tree branches, bicycles and insects) is a hard problem due to severe self-occlusions, repeated thin structures and surface discontinuities. In theory, a shape-from-silhouettes (SFS) approach can overcome these difficulties and use many views to reconstruct visual hulls that are close to the actual shapes. In practice, however, SFS is highly sensitive to errors in silhouette contours and the calibration of the imaging system, and therefore not suitable for obtaining reliable shapes with a large number of views. We present a practical approach to SFS using a novel technique called coplanar shadowgram imaging, that allows us to use dozens to even hundreds of views for visual hull reconstruction. Here, a point light source is moved around an object and the shadows (silhouettes) cast onto a single background plane are observed. We characterize this imaging system in terms of image projection, reconstruction ambiguity, epipolar geometry, and sh...

• Type: Conference
• Year: 2007
• Where: ICCV
• Authors: Shuntaro Yamazaki, Srinivasa G. Narasimhan, Simon Baker, Takeo Kanade
• Keywords: Computer Vision, ICCV 2007, Intricate Shapes, Multi-view Camerabased Imaging, Point Light Source, Severe Occlusions, Visual Hull Reconstruction