Showing papers by "Shai Avidan published in 1999"
01 Jan 1999
TL;DR: This paper considers the problem of reconstructing the 3D coordinates of a moving point seen from a monocular moving camera, i.e., to reconstruct moving objects from line-of-sight measurements only and shows that generally 9 views are sufficient for a unique reconstruction of the moving point and fewer views when the conic is a known type.
Abstract: We consider the problem of reconstructing the 3D coordinates of a moving point seen from a monocular moving camera, ie, to reconstruct moving objects from line-of-sight measurements only The task is feasible only when same constraints are placed on the shape of the trajectory of the moving point We coin the family of such tasks as "trajectory triangulation" In this paper we focus on trajectories whose shape is a conic-section and show that generally 9 views are sufficient for a unique reconstruction of the moving point and fewer views when the conic is a known type (like a circle in 3D Euclidean space for which 7 views are sufficient) Experiments demonstrate that our solutions are practical The paradigm of Trajectory Triangulation in general pushes the envelope of processing dynamic scenes forward Thus static scenes become a particular case of a more general task of reconstructing scenes rich with moving objects (where an object could be a single point)
32 citations
23 Jun 1999
TL;DR: This work proposes a new approach for dealing with dynamic scenes (rich with moving objects) in which once the camera motion is recovered, the 3D trajectory (straight line) of the moving target can be recovered-even when theMoving target consists of a single point.
Abstract: We consider the problem of reconstructing the location of a moving 3D point seen from a monocular moving camera, i.e., to reconstruct moving objects from line-of-sight measurements only. Since the point is moving while the camera is moving, then even if the camera motion is known, it is impossible to reconstruct the 3D location of the point under general circumstances. However we show that if the point is moving along a straight line, then the parameters of the line (and hence the 3D position of the point at each time instance) can be uniquely recovered, and by linear methods, from at least 5 views. Consequently, we propose a new approach for dealing with dynamic scenes (rich with moving objects) in which once the camera motion is recovered, the 3D trajectory (straight line) of the moving target can be recovered-even when the moving target consists of a single point.
30 citations