A psychoneural model of visual contrast

A typical set of visual contrast data can be described by a function which relates brightness responses to the luminance stimulus provided by a target that is viewed against an illuminated surround. This brightness-luminance function is represented by a psychoneural visual-contrast model having two channels, one corresponding to the brightness of the target and the other to the brightness of the surround. The principal ascending and descending pathways in each channel are represented by a submodel which is equivalent to the intensity-perception model described by MacKay. The interaction between the channels, which accounts for the perception of contrast, takes the form of nonlinear lateral inhibition. Brightness responses calculated with the use of the psychoneural contrast model correspond very closely to the data upon which the brightness-luminance function is based.