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:
May. 13, 2003
Filed:
Mar. 09, 2001
Michael H. Brill, Morrisville, PA (US);
Michael A. Isnardi, Plainsboro, NJ (US);
Albert P. Pica, East Windsor, NJ (US);
Sarnoff Corporation, Princeton, NJ (US);
Abstract
A channel is inserted into a sequence of frames for an image, by varying one or more display characteristics across a display in accordance with a spatio-temporal pattern applied to, for example, successive lines of each modified frame. The channel may be employed to watermark the image, and the watermark may be defined as W(x) and its complement [1−W(x)] in counter-phase rotations of successive lines in pairs of frames. The watermark information is applied in relatively still portions of the image with sufficient lightness level. A receiver includes a watermark detector that has a priori information about the watermark. The watermark detector examines specific regions of the displayed image over time, and tests the regions for the watermark during time intervals when the image remains relatively still.