Global surface reconstruction by purposive control of observer motion

What real-time, qualitative viewpoint-control behaviors are important for performing global visual exploration tasks such as searching for specific surface markings, building a global model of an arbitrary object, or recognizing an object? In this paper we consider the task of purposefully controlling the motion of an active, monocular observer in order to recover a global description of a smooth, arbitrarily-shaped object using the occluding contour. By studying the epipolar parameterization, we develop two basic behaviors that allow reconstruction of a patch around any point in a reconstructible surface region. These behaviors rely only on information extracted directly from images (e.g., tangents to the occluding contour), and are simple enough to be executed in real time. We then show how global surface reconstruction can be provably achieved by (1) integrating these behaviors to iteratively “grow” the reconstructed regions, and (2) obeying four simple rules.