The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 18, 2003
Filed:
Mar. 15, 1999
Viresh Ratnakar, Sunnyvale, CA (US);
Seiko Epson Corporation, Tokyo, JP;
Abstract
A steganographic method embeds hidden information like digital watermarks and digital fingerprints into an image by applying one or more zero-mean patches to a digital signal that conveys the image. Each zero-mean patch comprises elements having an average value substantially equal to zero. A copyright protection system is implemented by selecting one or more zero-mean patches in pseudo-random fashion, modifying the patches by perturbing their elements in pseudo-random fashion, and applying the patches to image pixels at locations that are selected in pseudo-random fashion. The copyright protection system further includes a procedure for checking for the presence of a watermark in a digital signal.