Model-based brightness constraints: on direct estimation of structure and motion

We describe a new direct method for estimating structure and motion from image intensities of multiple views. We extend the direct methods of B.K.P. Horn and E.J. Weldon (1988) to three views. Adding the third view enables us to solve for motion, and compute a dense depth map of the scene, directly from image spatio-temporal derivatives in a linear manner without first having to find point correspondences or complete optical flow. We describe the advantages and limitations of this method which are then verified with experiments using real images.