A statistical interpretation of human response to visual noise generated by toner particles deposited on background areas of electrophotographic copies is given. The constants of the theory are estimated from psychophysical measurements made on a set of noise samples. The study indicates that the background noise perception is connected with retinal areas nearly equal in size to those reported for the receptive fields of the ganglions in the fovea centralis.
George T. Bauer, "Noise on Nonimage Areas in Electrophotography," Appl. Opt. 13, 1053-1059 (1974)