Data compression using adaptive bit allocation and hybrid lossless entropy encoding
CA 2249259 C · Owner: America Online, Inc. · Inventors: Wang, Zhengrong; Houle, Paul Steven
Overview
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A method and apparatus for adaptive bit allocation and hybrid lossless entropy encoding. The system includes three components: (1) a transform stage (2) a , quantization stage, and (3) a lossless entropy coder stage. The transform stage (1) uses a wavelet transform algorithm. The quantization stage (2) adaptively estimates values for parameters defining an approximation between quantization size and the logarithm of quantization error and recursively , calculates the optimal quantization size for each band to achieve a desired bit rate. The baseband and subbands are transformed into quantization matrices using the corresponding quantization sizes. The lossless entropy coder stage (3) …
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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.
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- Filed March 19, 1997 and granted January 1, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 19, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 19, 2019.
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