Accuracy of velocity estimation by Reichardt correlators.

Autor: Dror RO; Department of Zoology, University of Cambridge, UK., O'Carroll DC, Laughlin SB
Jazyk: angličtina
Zdroj: Journal of the Optical Society of America. A, Optics, image science, and vision [J Opt Soc Am A Opt Image Sci Vis] 2001 Feb; Vol. 18 (2), pp. 241-52.
DOI: 10.1364/josaa.18.000241
Abstrakt: Although a great deal of experimental evidence supports the notion of a Reichardt correlator as a mechanism for biological motion detection, the correlator does not signal true image velocity. This study examines the accuracy with which realistic Reichardt correlators can provide velocity estimates in an organism's natural visual environment. The predictable statistics of natural images imply a consistent correspondence between mean correlator response and velocity, allowing the otherwise ambiguous Reichardt correlator to act as a practical velocity estimator. Analysis and simulations suggest that processes commonly found in visual systems, such as prefiltering, response compression, integration, and adaptation, improve the reliability of velocity estimation and expand the range of velocities coded. Experimental recordings confirm our predictions of correlator response to broadband images.
Databáze: MEDLINE