Combining Stereo and Visual Hull for On-line Reconstruction of Dynamic Scenes

In this paper, we present a novel system which combines depth from stereo and visual hull reconstruction for acquiring dynamic real-world scenes at interactive rates. First, we use the silhouettes from multiple views to construct a polyhedral visual hull as an initial estimation of the object in the scene. The visual hull is used to limit the disparity range during stereo estimation. The use of the constraints imposed by the silhouettes from the earlier processing stage reduces the amount of computation significantly. The restricted search range improves both the speed and the quality of the stereo reconstruction. In return, stereo information can compensate for some of the inherent drawbacks of the visual hull method, such as inability to reconstruct some concave regions.