Luc Florack,
Dept. of Biomedical Engineering, TUE, Eindhoven

Title: "Modeling foveal vision"

Abstract:
A geometric model is proposed for an artificial foveal vision system, and its 
plausibility in the context of biological vision is explored. The model is based 
on an isotropic, scale invariant two-form that describes the spatial layout of 
receptive fields in the the visual sensorium (in the biological context roughly 
corresponding to retina, LGN, and V1). It overcomes the limitation of the 
familiar log-polar model by handling its singularity in a graceful way. The log-
polar singularity arises as a result of ignoring the physical resolution 
limitation inherent in any real (artificial or biological) visual system. The 
incorporation of such a limitation requires the introduction of a physical 
constant, measuring the radius of the geometric foveola (a central region 
characterized by maximal resolving power). 
The proposed model admits a description in canonical coordinates that generalize 
the well-established log-polar coordinates, and that reduce to these in the 
asymptotic case of negligibly sized geometric foveola (or, equivalently, at 
peripheral locations in the visual field). Biological plausibility of the model 
is demonstrated by comparison with known facts on human vision.