Insight into the image processing of
flying insects might offer a boost to programmers of
future airborne robots.
Brains of insects are
common research subjects.
Approximately 100K to 1M neurons process an
image of the ground sweeping from front to back across the center of the
visual field in order to measure the ratio of the horizontal speed to
altitude. Researchers Frank
Ruffier and others call the reflex to keep the speed/altitude
ratio constant an "optic flow regulator". Relying on this
ratio alone eliminates the need to measure speed or altitude. If the
insect changes speed, the reflex changes altitude to keep the ratio
Optical flow is closely related to other types of image processing, and its not difficult to imagine how more elaborate forms of visual recognition evolved from it.
Optical flow is fundamentally about tracking the movement of small features over small amounts of time. This is a kind of correspondence problem between successive frames. Correspondence over time and correspondence over space are the same type of algorithm using the same centre/surround neural architecture, so with minor adaptations you can go from optical flow to stereo correspondence with two eyes. The ultimate vision system combines both tracking over time and correlation in space (spatio-temporal correspondence).