The optimal camera geometry and performance analysis of a trinocular vision system

In this paper, the projection location constraint is exploited to reduce ambiguous correspondences in trinocular systems. The inherent matching problems associated with the spurious features produced by overlapping among targets, the periodic structure of objects and the occlusion features were solved. The projection location constraint can be achieved by the deviation-to-distance transformation and the optimal epipolar constraint. The deviation-to-distance transformation transforms the location deviation of the extracted feature on an image plane to a maximum distance between the potential corresponding features and the epipolar line on another image for restricting the searching area of correspondences. The optimal epipolar constraint is obtained by adjusting the camera model before systems start to work. With the deviation-to-distance transformation and the optimal epipolar constraint, the arbitral area for searching the potential corresponding features can be made reasonably small. This not only saves computational time but also results in fewer ambiguous correspondences. In practice, the importance of the paper is that it proposes a very easy adjustment of camera geometry to simplify the most troublesome matching problem encountered in stereo systems. All the discussions and derivations are based on the geometry of the camera model and the mapping between the locations of the 3D features and their projection locations on the image planes. The non-ambiguity probability of the trinocular system is derived theoretically and verified by experimental results