The relationships that exist between the three dimensional (3D) structure and kinematics of a line moving rigidly in space and the two dimensional structure and kinematics (motion field) of its image in one or two cameras are investigated. The fundamental equations that relate its three dimensional motion to its observed image motion are established. The estimation of this motion field from a line based token tracker is shown. Stereo matches are then assumed to have been established between image segments and the use of the estimation of the motion field in the two images to compute part of the kinematic screw of the corresponding 3D is shown. The equations are linear and if several lines belong to the same object provide a very simple way to estimate the full kinematic screw of that object. The constrainment of the stereo matches by the motion field, by establishing necessary conditions that must be satisfied by the motion field of segments which are images of lines belonging to the same object, is shown. The idea is based upon the notion of invariance. The part of this theory which has been implemented uses Kalman filtering. Several experimental results using synthetic and real data are presented.     «

The relationships that exist between the three dimensional (3D) structure and kinematics of a line moving rigidly in space and the two dimensional structure and kinematics (motion field) of its image in one or two cameras are investigated. The fundamental equations that relate its three dimensional motion to its observed image motion are established. The estimation of this motion field from a line based token tracker is shown. Stereo matches are then assumed to have been established between imag...     »