Using illumination estimated from silhouettes to carve surface details on visual hull

Abstract

This paper deals with the problems of scene illumination estimation and shape recovery from an image sequence of a smooth textureless object. A novel method that exploits the surface points estimated from the silhouettes for recovering the scene illumination is introduced. Those surface points are acquired by a dual space approach and filtered according to their rank errors. Selected surface points allow a direct closed-form solution of illumination. In the mesh evolution step, an algorithm for optimizing the visual hull mesh is developed. It evolves the mesh by iteratively estimating both the surface normal and depth that maximize the photometric consistency across the sequence. Compared with previous work which optimizes the mesh by estimating the surface normal only, the proposed method shows better convergence and can recover better surface details, especially when concavities are deep and sharp.