Method and apparatus for geographic coordinate data storage
US5995970A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1997 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Aug 1, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99945
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The storage space required for representing geographic features is reduced by determining an optimum number of bits that can be used to store coordinate data along each separate axis. Any coordinate change that cannot directly fit within the optimum bit size is subjected to an escape sequence made up of one or more special values and a normal value that fits in the optimum bit size. The special values are obtained by a predetermined calculation for each bit size. If all changes for one axis are in the same direction and special values are not needed, a global sign can be used to further enhance use of the available space on the storage medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.