Field-based watermark insertion and detection
CA 2321034 A1 · Owner: Nec Corporation · Inventors: Cox, Ingemar J.; Miller, Matthew L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A digital watermark is inserted into multimedia data (102) containing two image fields (106, 108) by placing a positive watermark into a first field (110) and a negative watermark into a second field (112). The positive watermark and negative watermark are opposite of one another. The two fields can be interlaced fields of a field-based video signal or alternate rows of a frame-based video signal. The watermark is extracted from field-based watermarked data (120) by separating the watermarked data (120) into two fields and subtracting one of the fields from the other field to generate a watermarked signal. The resultant watermarked signal is processed in a conventional manner to …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 14, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 14, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 14, 2021.
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Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.