Abstract

In this paper we describe a fiexible approach for determin- ing the relative orientation of the camera with respect to the scene. The main premise of the approach is the fact that in man-made environments, the ma jority of lines is aligned with the principal orthogonal directions of the world coordinate frame. We exploit this observation towards eff- cient detection and estimation of vanishing points, which provide strong constraints on camera parameters and relative orientation of the camera with respect to the scene. By combining eficient image processing techniques in the line detection and initialization stage we demonstrate that simultaneous grouping and estimation of vanishing directions can be achieved in the absence of internal parameters of the camera. Constraints between vanishing points are then used for partial calibration and relative rotation estimation. The algorithm has been tested in a variety of indoors and outdoors scenes and its e?ciency and automation makes it amenable for implementation on robotic platforms.