Perceptual consequences of visual inhomogeneity.

Early visual processing is usually considered as a linear filtering stage. In fact, the perceived image is usually thought of as the result of filtering the input image with the contrast sensitivity function of the whole visual system.Yet, visual performance in any spatial resolution task is best at the fovea and quickly declines with increasing eccentricity, which suggests that visual processing is not the same at all locations in the visual field. This is known as visual inhomogeneity.