EURion constellation
From Just Solve the File Format Problem
EURion constellation (also Omron rings) is a pattern of symbols incorporated into a number of secure documents such as banknotes, checks, and ownership title certificates designs worldwide since about 1996. It is added to help imaging software detect the presence of such a document in a digital image. Such software can then block the user from reproducing banknotes to prevent counterfeiting using colour photocopiers.
It has since been supplanted by Counterfeit Deterrence System (CDS)
See also
