Modeling the contrast-sensitivity function of the human visual system

Based on a representation of the receptive fields of the human retina, a mathematical model has been developed that describes the primary stage of the processing of visual information, taking into account the internal noise of the photoreceptors. The hypothesis is advanced that the visual perception power of an image is the result of the sum of the reactions of the ganglion cells to whose receptive fields the action of the stimulus propagates. Based on the proposed model, the contrast-sensitivity function (CSF) of the human visual system is calculated. It is shown that, for stimuli in the form of regular periodic gratings with alternating light and dark strips in the region of high spatial frequencies, the CSF has resonance minima whose spectral position and depth depend on the ratio between the sizes of the central and peripheral zones of the receptive fields. (C) 2015 Optical Society of America.