Compression/decompression method for image data
CA 2126307 C · Owner: Nec Corporation · Inventors: Watanabe, Mitsuhiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A compression/decompression method for image data allows addition of a code amount control amount in units of data of one block without necessitating an excessive header capacity. In compression a, quantization conversion coefficient of a quantization conversion coefficient set is replaced with a code amount control amount, and a resulted quantization conversion coefficient set is coded, whereafter a quantization coefficient of a quantization coefficient set corresponding to the code amount control amount of the quantization conversion coefficient set is changed to 0. In decompression, the quantization coefficient set is extracted, and coded data are decoded in units of data of one block. …
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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 June 20, 1994 and granted October 13, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 20, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 20, 2016.
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Timeline
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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.