METHOD AND DEVICE FOR THE INSERTION OF GUILLOCHE PATTERNS

• Main Authors: JOURLIN, MICHEL, LEIBENGUTH, JOSEPH, BOUABDELLAH, MOHAMED, CARRÉ, MAXIME
• Format: Patent
• Language: English; Polish
• Published: 06.02.2023
• Subjects: BOOK COVERS; BOOKBINDING; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDEDFOR; FILES; LOOSE LEAVES; MOVABLE-STRIP WRITING OR READING APPARATUS; PERFORMING OPERATIONS; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITYFEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOTOTHERWISE PROVIDED FOR; SPECIAL PRINTED MATTER; TRANSPORTING

The invention concerns a method for extracting guilloche patterns (601-608) from a secure document (600) likely to be degraded, the method comprising the following operations:- determining (710) a contrast card (c) of at least one portion of the secure document that includes the guilloche patterns;- identifying (720), on this contrast card an optimal percolation trajectory; and- extracting (730) the optimal percolation trajectory, said trajectory corresponding to the guilloche pattern.The invention also concerns a method of authentication of the guilloche patterns of a secure document likely to be degraded, involving:- the preceding extraction operations, and- an operation (740) of comparing each extracted guilloche pattern with a corresponding theoretical guilloche pattern.