Focal length change compensation for monocular slam

In this paper, we propose a method for handling focal length changes in the SLAM algorithm. Our method is designed as a pre-processing step to first estimate the change of the camera focal length, and then compensate for the zooming effects before running the actual SLAM algorithm. By using our method, camera zooming can be used in the existing SLAM algorithms with minor modifications. In the experiments, the effectiveness of the proposed method was quantitatively evaluated. The results indicate that the method can successfully deal with abrupt changes of the camera focal length.