Identification data insertion and detection system for digital data
CA 2225867 C · Owner: Nec Personal Computers, Ltd. · Inventors: Wakasu, Yutaka
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides an identification data insertion and detection system for digital data which improves the detection ratio when an image is converted into frequency components and electronic watermark data are embedded in a portion of an image having a strong frequency component and besides allows a statistical similarity to be calculated with a higher degree of accuracy. The identification data insertion system for digital data includes a DCT calculator for extracting blocks of 8 x 8 pixels from within a current image and performing DCT (discrete cosine transform) calculation for the blocks a quantizer for quantizing data outputted from the DCT calculator a quantization table for …
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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 December 29, 1997 and granted September 11, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 29, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 29, 2019.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.