Random pattern generation using coherent optical spatial filtering.

Coherent optical spatial filtering is used to generate 2-D random patterns for use in studies of image noise perception. Some of the problems encountered are: small filter dimensions due to low spatial frequencies required; obtaining a noise source with a suitable Wiener spectrum; and the nonlinearity of the recording process. A procedure that overcomes these difficulties is discussed, and an example using a circularly symmetric bandpass filter is presented.