A Novel Omnidirectional Stereo Vision System with a Single Camera

Abstract

Wide field of view is the most attractive feature of the omnidirectional vision. There exist two approaches to omnidirectional stereo imaging with a single camera. They use: (1) a double lobed mirror (Fiala & Basu, 2005)(Cabral et al., 2004), or (2) two mirrors (Jang et al., 2005). In this paper, a third approach is described using a mirror and a concave lens. By adjusting the position of the concave lens, it is possible to control the disparity between two stereo images and the accuracy of the 3D distance computation. Since the optical components adopted in the proposed system are commercially available, the proposed omnidirectional stereo imaging system is compact and cost-effective. Based on the simple optics composed of the reflection and the refraction on the convex mirror and the concave lens, an expression for the 3D distance is derived. The proposed method is versatile in the sense that it is also applicable to different types of convex mirrors, e.g., the parabolic mirror. The second approach (2) mentioned above involves a relatively lengthy baseline, and therefore a longer depth range than (1) and the approach proposed in this paper. Two simple ways of getting longer range of sight with (1) and the approach in this paper are to use a larger mirror or a camera with higher resolution.