Buffer overflow and underflow control for facsimile transmission
US6456399B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1998 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Feb 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/33357
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a facsimile system, buffer underflow is prevented by forcing the transmit pointer to wait at a current end-of-line (EOL) symbol and transmit fill bits until there are at least two EOL symbols stored in the buffer. Buffer overflow is controlled by selectively dropping lines if the write pointer approaches too close to the transmit pointer and the difference between successive lines is sufficiently small (selective line-dropping), dropping lines whenever a permitted maximum buffer size is exceeded, and gradually changing the permitted distance between transmit and write pointers and permitted maximum buffer size as the image is scanned to accomplish a smooth buffer flushing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.