The spatial accuracy of point clouds generated from a mobile stereo camera set is very sensitive to the intrinsic and extrinsic camera parameters (i.e., camera calibration) used in stereo image-based three-dimensional (3D) reconstruction methods. The existing camera calibration algorithms induce a significant amount of error owing to poor estimation accuracy in camera parameters when they are used for large-scale scenes such as mapping civil infrastructure. This leads to higher uncertainties in the location of 3D points, and may result in the failure of the whole reconstruction process. This paper proposes a novel procedure to address this problem. It hypothesizes that a set of multiple calibration parameters created by videotaping a moving calibration pattern along a specific path can increase overall calibration accuracy and ultimately enhance the Euclidean accuracy of the generated point cloud. This is achieved by using conventional camera calibration algorithms to perform separate estimations ...

Multistep Explicit Stereo Camera Calibration Approach to Improve Euclidean Accuracy of Large-Scale 3D Reconstruction

This work addresses the problems of (i) self-calibration of a moving camera observing a 3D scene composed by planar structures and (ii) scene segmentation and reconstruction. Although there exist some works intending to deal with these problems, most of them are based on the estimation of the epipolar geometry, non-linear optimization, or linear systems that do not incorporate geometrical consistency and may produce undesirable side-effects. In this paper, we propose a novel iterative linear algorithm that exploits the geometrical and algebraic constraints induced by rigidity and planarity in the scene. Instead of solving a complex multi-linear problem, we solve iteratively several linear problems: coplanar features segmentation, planar projective transferring, epipole computation, and all the plane intersections. Linear methods allow our approach to be suitable for real-time localization and 3D reconstruction, e.g. for autonomous mobile robots applications. Furthermore, we avoid the explicit epipolar geometry computation and all the stability problems commonly associated with it.

Mario Santes

Papers

Automatic Camera Calibration with Structure and Motion Recovery from Two Views of a Polyhedral Structure