Bitwise adaptive encoding using prefix prediction
US7274671B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 9, 2001 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | May 5, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/40
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A technique is presented for compressing data which leverages the frequency of an escape symbol for better compression. The prefix of a data string is evaluated and the probability of all characters that might succeed it is predicted in tabular form. Symbols are designated “Hit” or “Miss” based upon whether they are in the table. A binary tree is generated by partitioning nodes into Zero and One groups based on a single bit value. A partition bit is chosen to maximize the difference of probability sums of Hit symbols in Zero and One groups, with exceptions for partitions having non Hit symbols in one of the groups. A probability value is assigned to each branch, based on the probabilities of Hit and Miss symbols. Encoding or decoding a symbol is facilitated by encoding or decoding the branch probabilities on the shortest path from the root to the leaf node containing the symbol using arithmetic encoding or decoding method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.