Relative scale estimation between two camera motions

In structure from motion, if two metric structures are given, the unknown scale between them can be resolved by constraining the rigidity of the metric space. There exist two well-known approaches. The first one is the pose estimation which aims to find the pose of a camera for known 3D points. The second one is the scale estimation whose goal is to resolve the scale after estimating the motion between cameras. Recently, the former way is preferred because of the vulnerability of the scale estimation, the weakness to the image noise. In this paper, we thus propose a robust method which can overcome the weakness of the scale estimation by considering the uncertainty of reconstructed 3D points. Additionally, the rotation matrix is directly corrected under the structural consistency constraint. To illustrate the performance of the method, we demonstrate some examples of large-scale reconstructions and compare the results.