Method and device for testing value documents

摘要

The invention relates to a method and apparatus for recognizing forged value documents, for example composed forgeries which are assembled from parts of different value documents. In the inventive method, the signal intensity of a measuring signal is determined at a plurality of measuring points on a value document. For one or more selected groups of measuring points which are disposed in particular along certain directions on the value document there are determined gradient values of the signal intensities. The gradient values of a group are subsequently linked to form a connection strength of the group which provides a quantitative statement about the extent to which a large gradient value exists consistently within the particular group. From a relatively great connection strength there can be inferred the presence of a separating line in the area of the selected group of measuring points.

主权项

1. A method for checking value documents for the presence of separating lines at which the value document is assembled comprising the steps:
determining signal intensities of a measuring signal at a plurality of measuring points on a value document, selecting measuring points from the plurality of measuring points on the value document to form a group of the measuring points, wherein the selection of the group is effected in dependence of a typical separating line position on the value document, determining gradient values of the signal intensities for the measuring points of the group, linking the gradient values of the group of measuring points on the value document for ascertaining a connection strength of the group, wherein the connection strength is determined from the gradient values of the group of measuring points on the value document, and evaluating the connection strength.