Analysis of object motion and camera motion in real scenes

In this paper a contour based motion estimation technique is presented applied to the measurement of the optic-flow field from image sequences. In particular two experimental situations are considered: the former, in which a fixed camera analyzes a scene with some moving objects in order to detect their trajectories; the latter, in which a sensor moves in a static environment, determining the depth map of the "world". For the first case, we compute for every contour the prevalent direction of movement. For the second, we solve the problem of recovering the 3D structure of the worldby computing the depth field from a sequence of images acquired during a motion of the camera, controlled in order to mantain the fixation point (i.e. the point projected over the image plane) still during the entire sequence. The algorithm has proved to be very robust in real scene analysis and an acceptable time for computation is required. Some experimental results are presented.