Gradient-Based Flow Segmentation and Location of the Focus of Expansion

In previous papers it has been shown how it is possible to sense fragmentary motion and local edge orientation to a high accuracy, directly from illuminance gradient data present in pairs of frames from a time sequence. It has also been suggested how such data may be used to generate optic flow maps. The present paper looks at the practicability of generating such optic flow maps and at the possibilities of scene segmentation and determination of focus of expansion from such maps. It is shown that flow field scene segmentation is easily realisable, and that the focus of expansion can be determined to a high accuracy (typically better than 1 pixel).