Signal coding
CA 2093801 C · Owner: Beaumont, David Owen · Inventors: Nilsson, Michael Erling; Morrison, David Geoffrey; Beaumont, David Owen
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of coding a video signal for transmission is described which comprises coding data representing the video signal by a base layer coding operation which includes base layer quantizer having a base layer quantization step size to provide coded video data for transmission; deriving inverse-coded video data by carrying out an inverse base layer coding operation on the coded video data; deriving difference data from the data representing the video signal and the inverse coded video data; and coding the difference data by an enhancement layer coding operation only when the energy of the difference data exceeds a variable threshold, the threshold being inversely proportional to the base …
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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 October 15, 1991 and granted December 23, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 15, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 15, 2013.
- 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.