Patent · US Active

Method and apparatus to mark a document using a combination between guilloches and watermarking, method and apparatus to read previous combination

US8406459B2 · kind B2 · utility

0Cited by

0References

10Claims

0Family size

Assignees

GEMALTO SA · FR
Gemalto Oy · FI

Inventors

Frederic Ros · Meudon, FR
Christophe Mourtel · Meudon, FR
Teemu Pohjola · Stuttgart, DE

Key dates

Filing date	Nov 28, 2008
Grant date	Mar 26, 2013
Priority date	—
Expiry date	Sep 1, 2029

Classification

Technology area (CPC G)Physics
CPC primaryG06T2201/0052
WIPO fieldComputer technology
WIPO sectorElectrical engineering

Abstract

Guilloches (preventing modification) and watermarking (preventing substitution) technologies are combined to protect a medium, such as a card or a passport. The major idea stems from their dual role for medium authentication: the presence of one is needed to check the validity of the other one. By nature, the guilloche network is visible in the image and easily detectable by image processing. This network is therefore used to generate reference points as elements of synchronization to retrieve watermark information originally embedded in the medium that has submitted an RST transformation. These reference points are by nature stronger than any other means involving invisible templates in the spatial or Fourier space.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.