Many efforts for motion on a plane have been done under a condition that the true horizontal component of binocular optical flows is obtained. There are many straight like line edges in the real environment. Therefore, due to the aperture problem, the true horizontal component of movement of a point at a straight long edge in the retinal image by analysis of the local area alone is unknown. The integration process of the apparent optical flows of the left eye and right eye, the extraction method of true optical flow and the prediction method of collision location and collision time for moving objects on a horizontal plane are presented in this paper.
