Image coding by use of discrete cosine transforms
CA 2173746 A1 · Owner: Polaroid Corporation · Inventors: Reisch, Michael L.; Wober, Munib A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Image coding methods and apparatus employing discrete cosine transforms for suppressing and/or reducing blocking artifacts using a JPEG file format. The methods can be implemented on JPEG hardware slightly modified to provide access to discrete cosine transform coefficients Filtering techniques by which an overlap procedure for implementing the inventive methods are also disclosed.
Read the whole patent
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 November 30, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 30, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 30, 2016.
- 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.