Variational approach to moire pattern synthesis

Moire phenomena occur when two or more images are nonlinearly combined to c reate a new superposition image. Moire patterns are patterns that do not ex ist in any of the original images but appear in the superposition image, fo r example as the result of a multiplicative superposition rule. The topic o f moire pattern synthesis deals with creating images that when superimposed will reveal certain desired moire patterns. Conditions that ensure that a desired moire pattern will be present in the superposition of two images ar e known; however, they do not specify these images uniquely. The freedom in choosing the superimposed images can be exploited to produce various degre es of visibility and ensure desired properties. Performance criteria for th e images that measure when one superposition is better than another are int roduced. These criteria are based on the visibility of the moire patterns t o the human visual system and on the digitization that takes place when the images are presented on discrete displays. We propose to resolve the freed om in moire synthesis by choosing the images that optimize the chosen crite ria. (C) 2001 Optical Society of America.