Extraction and insertion of a digital signature into an image for copyright or security reasons where the geometrical transformations necessary are first determined by selection of a subset of reference points in the original

摘要

Invention relates to procedures and devices for extraction of a digitized image such as a signature from an original analogue image and insertion into a digitized image where the inserted image may well be hidden or in the form of a watermark for security or protection of copyright reasons. Insertion procedure has the following steps: detection (E10) of points of interest in the image; selection (E11) of a sub-set of the points of interest to define a geometrical reference for the image; calculation (E12) of reference data necessary to transform the geometrical reference for a type of predetermined geometrical transforms and coding of such information in a reference key (Kr) that is inserted in the digital image. Independent claims are made for devices for extraction and insertion of digitized signature data.