Lempel-Ziv (LZ)-based data compression employing implicit variable-length distance coding
US9160362B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 2014 |
| Grant date | Oct 13, 2015 |
| Priority date | — |
| Expiry date | May 8, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/40
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Lempel-Ziv (LZ)-based data compression employing implicit variable-length distance coding is disclosed. Distances in LZ-based data compression length and distance blocks are implicit variable-length encoded during data compression to avoid padding encoded distances with extra bits (e.g., trailing 0's) that require fewer bits for storage than the number of bits needed to store maximum distance length. This reduces distance bit lengths in compressed output data to further reduce data size. During data compression, a distance table is generated that contains entries each having an assigned base and a number of extra bits to be read in compressed data during data decompression. In this manner, during data decompression, the entries in the distance table can be consulted to determine the number of bits in the variable-encoded distance in the compressed data to be read since the encoded distances can be encoded in the compressed data in fewer bits and without bit padding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.