We propose a direct method for locating the focus of expansion (FOE),
based on simple parallel computations in selected regions of the image
; each is a circular patch around an estimated FOE. Simple computation
s allow determining the direction from the estimated to the true FOE.
The best estimate of the intersection of the so-called FOE constraint
lines for several regions gives the location of the FOE. Some analysis
allows us to assign a confidence measure to the information from each
local region, in order to give more weighting to the most reliable da
ta. Hence, the FOE can be located with more accuracy, even when the da
ta from various local regions lacks sufficient information. Results of
experiments with real images of various texture content are given to
demonstrate the performance of the method. (C) 1996 Academic Press, In
c.