Perceptually-adapted image coding system
CA 2014935 C · Owner: Safranek, Robert J. · Inventors: Johnston, James D.; Safranek, Robert J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An image-coding system reduces image data redundancies and perceptual irrelevancies through progressive sub-band coding. The image is separated into aplurality of sub-bands. From this sub-band information a perceptual metric, based, on the properties of the sub-band filters quantizer error distribution, and properties of the human visual system, is determined which provides the maximum amount of coding noise that may be introduced to each pixel in every sub-band without causing perceptible degradation of the coded image. This perceptual metric is used to adjust the quantizer used in encoding each sub-band signal. In addition redundancy in the, output of the quantizer is reduced using a …
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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 April 19, 1990 and granted February 6, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 2012.
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.