METHOD OF ADDITIONAL AUTHENTICATION OF VALUABLE DOCUMENT Russian patent published in 2021 - IPC G07D7/20 

FIELD: computing.

SUBSTANCE: invention relates to the field of automated authentication of protected documents, and concerns a method of additional verification of a valuable document authenticity. When implementing the method, a digital image of the document being checked is obtained and the location of the control zone of the digital image of the document is determined, where there is a moire image formation property. When checking, a digital image is used consisting of sequentially scanned lines, as well as the skew angle of the document being checked in relation to the scanning direction. When scanning, the length of the registration area on the document measured in the scanning direction, from which the sensor receives at least 80 percent of the radiation recorded in the course of a single line scanning, is less than the interline spacing of the checked document relative to the sensor. The check consists in determining the presence in the control zone in the digital image of the checked document of the controlled features characteristic of the moiré image formed in the digital image of the authentic document for the specified type and orientation in the same control zone, with the skew angle of the original document equal to the skew angle of the checked document.

EFFECT: increased reliability of the confirmation of the protected document authenticity.

14 cl, 10 dwg