Method and apparatus for encoding, decoding and transmitting data in compressed form
US5153591A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 27, 1990 |
| Grant date | Oct 6, 1992 |
| Priority date | — |
| Expiry date | Dec 27, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/3088
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Data compression and decompression utilizing, e.g., the Ziv-Lempel algorithm is simplified by utilizing a tree structure for the dictionary in which alternative symbols at a given position in a symbol sequence (a,b,c) are linked by linking pointers R of a first type and successive symbols (ab,bc,ca,aba,abb,abc) are linked by linking pointers D of a second type. For example, the sequence ab may continue with any one of the symbols a,b, and c grouped together by R pointers in a list below the final symbol of the sequence ab. Each symbol is defined by an associated pair of D and R pointers, in conjunction with a parent pointer P which identifies its parent. Symbols having no D pointers extending therefrom are pruned from the tree and transferred to a free list as shown in FIG. 8(b).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.