Dynamic vergence

Vergence control enables fixation of points in visual space at different distances from the observer. It must provide not only a stable fixation, but a stable binocular fusion and a fast and accurate reaction to changes in the environment. To obtain this kind of performance the paper focuses on the use of two dynamic quantities as inputs for the vergence control process: the temporal evolution of the degree of fusion and the rate of expansion/contraction of image patterns as a consequence of the relative motion between an object and the observer. The use of space variant image geometry is proposed and some advantages of this approach are discussed in order to demonstrate the relevance of log-polar image geometry in relation to vergence control. Three experiments are described: the first concentrates attention on the results of visual processing algorithms in an open loop situation; the other two, illustrate the behavior of the real-time vergence system in response to continuous changes of depth of a controlled target