A unified approach to camera fixation and vision-based road following

Both camera fixation and vision-based road following are problems that involve tracking or fixating on 3-D points and features. This paper presents a unified theoretical approach to analyzing camera fixation and vision-based road following. The approach is based on the concept of equal flow circles (EFCs) and zero flow circles (ZFCs). Using EFCs it is possible to locate points in space relative to the fixation point, and predict the behavior. The camera´s instantaneous direction of translation and the fixation point determine the plane on which the EFCs can be found. We show that points on an EFC inside the ZFC produce optical flow that is opposite in sign to that produced by points outside the ZFC. When a point in space crosses a ZFC it produces zero flow. For explanation purposes we analyzed a special case of motion. However, a similar approach can be taken for a more general motion of the camera. The analysis for the current motion can also be extended to find equal flow curves