US 6,674,886 B2 · Method and system for recognizing security documents

Abstract

A document is analyzed to determine whether it is a banknote or the like, by reference to image data corresponding to the document. Two analysis techniques may be used, one based on detection of a visible pattern characteristic of a security document, the other based on detection of a steganographic digital watermark characteristic of a security document. If either characteristic is found, the image is flagged, and appropriate anti-counterfeiting steps may be taken. Detection of the visible pattern can be performed using a series of successively more rigorous tests. If the image fails a test, successive testing steps can be skipped, speeding the process. Hough transform-based pattern recognition techniques are used in some embodiments. Provision of both a visible pattern detector and a watermark detector in a single apparatus enhances detection reliability, while permitting various implementation efficiencies.

Claims8

Dependent claims

A method of processing image data to screen for security document images comprising, in the order stated:

(a) performing a first analysis on the image data;
(b) if the first analysis indicates the image data does not correspond to a security document, skipping steps (c)-(e)
(c) performing a second analysis on the image data;
(d) if the second image analysis indicates the image data does not correspond to a security document, skipping step (e);
and
(e) flagging the image data as corresponding to a security document;
wherein at least one of the analyses employs a Hough-based transform to detect a two-dimensional, rotationally invariant feature.

4 more elements

Dependencies are inferred from the claim text.

Method and system for recognizing security documents

Life of this patent

Method and system for recognizing security documents

Life of this patent

Abstract

Claims8