Designing Moiré Patterns

Moiré phenomena occur when two or more images are non-linearly combined to create a new “superposition image”. Moiré patterns are patterns that don’t exist in any of the original images but appear in the superposition image for example as the result of a multiplicative superposition rule. The topic of moiré pattern synthesis deals with creating images that, when superimposed, will reveal certain desired moiré patterns. Conditions ensuring that a desired moiré pattern will be present in the superposition of two images are known, however they do not specify these images uniquely. The freedom in choosing the superimposed images can be exploited to produce various degrees of visibility and ensure desired properties. Performance criteria for the images that measure when one superposition is better than another are introduced. These criteria are based on the visibility of the moiré patterns to the human visual system and on the digitization which takes place when presenting the images on discrete displays. We here propose to resolve the freedom in moiré synthesis by choosing the images that optimize the chosen criteria.