Camera motion from brightness on lines. Combination of features and normal flow

摘要

In this paper feature extraction (straight lines) and optical flow techniques are combined to obtain camera motion. The expressions relating the brightness constraint to the 3D localization and motion of a line and its projected motion are established. These expressions allow to obtain the 3D motion of a camera using brightness information in image regions supporting straight lines of known 3D localization. The algorithm needs neither correspondence computation nor full optical flow computation and uses a direct formulation. It has been compared experimentally with a geometrically equivalent approach based on corresponding features, showing better results for close images. The proposed method can be combined with a feature-based approach, improving classical methods when obtaining 3D information using triangulation is ill-conditioned.