Rectification of Stereoscopic Video for Planar Catadioptric Stereo Systems

Planar mirror has been used successfully in the catadioptric stereo systems to capture image pairs with only a single camera. These planar catadioptric stereo (PCS) systems not only provide radiometric advantages over traditional two camera stereo, but also reduce the complexity and cost of acquiring stereoscopic video. One problem with these PCS sensors is that image pairs taken by them are usually not rectified and can not be viewed directly or compressed efficiently. Although several conventional methods have been suggested for rectification, features of the PCS system are not employed to optimize the design and rectified results are not evaluated. In this paper, we investigated features of the PCS system and found that epipolar geometries of certain systems can be approximated by affine. On the basis of this affine property, an effective algorithm is proposed for rectifying image pairs they acquired. This new approach reduces the number of parameters to be estimated from 11 in the conventional method to only four. The greatly reduced number of parameters makes the new method more robust and easier to implement. A PCS system was selected for evaluation and experimental results showed that the proposed method not only outperformed the conventional approaches but also worked quite well both visually and quantitatively for all the image pairs under test