The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 19, 2016
Filed:
Sep. 08, 2010
Nicolas Rudaz, Veyras, CH;
Martin Kutter, Remaufens, CH;
Frederic Jordan, Les Paccots, CH;
Jean-claude Gilles, Frankfurt am Main, BE;
Pierre Durant, Frankfurt am Main, DE;
Nicolas Rudaz, Veyras, CH;
Martin Kutter, Remaufens, CH;
Frederic Jordan, Les Paccots, CH;
Jean-Claude Gilles, Frankfurt am Main, BE;
Pierre Durant, Frankfurt am Main, DE;
EUROPEAN CENTRAL BANK (ECB), Frankfurt am Main, DE;
Abstract
The present invention proposes a method for generating a security bi-level image used to form one of the inks of a banknote, said image comprising an original bi-level image and a security pattern, said security pattern being obtained in the spatial domain by the inverse Fourier transform of the combination in the frequency domain between the Fourier transform of an auxiliary image and a two-dimensional sweep, said two-dimensional sweep being a circularly symmetric, two-dimensional pattern created by sweeping a self-similar, one-dimensional function along a 360-degree arc, such as said security pattern being detectable from the maximum value of the cross-correlation of said one-dimensional function with the Fourier transform of one line of said banknote, said method comprising the step of: —determining a distance map of the original bi-level image, —generating a merged image by linearly interpolating at least a part of said distance map with said security pattern, —thresholding the merged image to obtain the security bi-level image, —applying the security bi-level image on a support.