Reversible overlap operator for efficient lossless data compression
CA 2526366 C · Owner: Microsoft Corporation · Inventors: Tu, Chengjie; Malvar, Henrique Sarmento; Srinvasan, Sridhar
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An efficient lapped transform is realized using pre- and post-filters (or reversible overlap operators) that are structured of unit determinant component matrices. The pre- and post-filters are realized as a succession of planar rotational transforms and unit determinant planar scaling transforms. The planar scaling transforms can be implemented using planar shears or lifting steps. Further the planar rotations and planar shears have an implementation as reversible/lossless operations giving as a result, a reversible overlap operator.
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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 November 9, 2005 and granted October 8, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 9, 2025.
- Certificates of supplementary protection extend only drug patents, and it isn't classified as one.
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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.