Invisible junction feature recognition for document security or annotation

摘要

The present invention uses invisible junctions which are a set of local features unique to every page of the electronic document to match the captured image to a part of an electronic document. The present invention includes: an image capture device, a feature extraction and recognition system and database. When an electronic document is printed, the feature extraction and recognition system captures an image of the document page. The features in the captured image are then extracted, indexed and stored in the database. Given a query image, the features in the query image are extracted and compared against those stored in the database to identify the query image. The feature extraction and recognition system of the present invention is integrated into a multifunction peripheral. This allows the feature extraction and recognition system to be used in conjunction with other modules to provide security and annotation applications.