Method and apparatus for data compression and restoration
US4872009A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 7, 1987 |
| Grant date | Oct 3, 1989 |
| Priority date | — |
| Expiry date | Dec 7, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/46
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method of data compression for recording data on a recording medium such as a magentic tape, a method of data restoration for data which has been compressed for recording, and an apparatus of data compression and restoration prescribe the data to be compressed based on type or value and encode the compression object data, thereby reducing the number of bits necessary to indicate the compression object data. Compression is implemented only for consecutive data fewer in number of repeating consecutive bytes than a certain number, thereby reducing the number of bits necessary to indicate the number of bytes of the consecutive data. A compression mark indicative of compression is appended to the compressed data, consisting of data made by encoding the compression object consecutive data and data indicating the number of bytes of the data, either at the front or rear of the compressed data, whereby an input data string can be compressed drastically and compressed data, even including errors, can be restored.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.