[Definition] Moire (or Moiré)

[Doug Nelson]

Moire (pronounced "more-RAY") is a optical effect caused by two intersecting patterns. It is common when working with printing screens, but can also manifest with finely-patterned image elements. The classic example is the lines that appear when scanning a half-tone image.

It is usually associated with scanning, but can also pop up when applying manipulations to finely-patterned subjects.