Projective Visual Hulls

Svetlana Lazebnik

M.S. Thesis

Abstract

This thesis presents an image-based method for computing the visual hull of an object bounded by a smooth surface and observed by a finite number of perspective cameras. The essential structure of the visual hull is projective: to compute an exact topological (combinatorial) description of its boundary, we do not need to know the Euclidean properties of the input cameras or of the scene. Unlike most existing visual hull computation methods, ours requires only a projective reconstruction of the camera matrices, or equivalently, the epipolar geometry between each pair of cameras in the scene. Starting with a rigorous theoretical framework of oriented projective geometry and projective differential geometry, we develop a suite of algorithms to construct the visual hull and associated data structures. The thesis discusses our implementation of the algorithms, and presents experimental results on synthetic and real data sets.


Research — Svetlana Lazebnik (slazebni -at- uiuc.edu)