Structure from motion: sparse versus dense correspondence methods

Researchers in image processing and computer vision fields have agonized over the last twenty-five years, to come up with robust methods for the structure from motion (SFM) problem. Two dominant approaches, based on flow and feature correspondences have been pursued. Despite tremendous efforts, only limited success in special cases can be claimed. We feel that with the availability of newer, general, robust methods for computing optical flow, fast methods for estimating the focus of expansion (FOE), inexpensive cameras, and inertial information, robust, real-time solutions to this problem may be possible in the near future. Some of our recent work in these areas is presented.