Recursive Estimation of Motion, Structure, and Focal Length

We present a formulation for recursive recovery of motion, pointwise structure, and focal length from feature correspondences tracked through an image sequence. In addition to adding focal length to the state vector, several representational improvements are made over earlier structure from motion formulations, yielding a stable and accurate estimation framework which applies uniformly to both true perspective and orthographic projection. Results on synthetic and real imagery illustrate the performance of the estimator. Index Term-Structure from motion, camera model, camera calibration, recursive estimation, 3D representation, 3D modeling.