Spherical alignment of imagers using optical flow fields

Optical flow fields can be used to recover some components of the camera ego-motion such as velocity and angular velocity. In this paper, we discuss the use of optical flow fields to estimate the relative orientation of two imagers with non-overlapping fields of view. The algorithms proposed are based on a spherical alignment technique which is closely related to rapid transfer alignment methods used to align aircraft inertial navigation systems. Of particular importance is the relationship between the accuracy of the optical flow field (which is dependent upon the complexity of the scene and the resolution of the cameras) and the accuracy of the resultant alignment process.