Method for compression and transmission of video information
US4679094A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1986 |
| Grant date | Jul 7, 1987 |
| Priority date | — |
| Expiry date | Oct 14, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/46
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A facsimile transmitter capable of transmitting graphic as well as text material, by telephone or wireless. A digital code derived from scanning the document to be transmitted is truncated from eight bits per pixel to six bits per pixel. The three most significant bits of each pixel are run length encoded in eight bit bytes, so that wherever the same three most significant bits appear in adjacent pixels, these three bits are transmitted once, followed by a five bit code indicating the number of times (up to 32 times) the same three most significant bits are repeated in succeeding pixels. The resulting eight bit bytes are similarly run length encoded, so that the transmission of the three most significant bits of each pixel is double run length encoded. An eight bit fine resolution byte is transmitted for each eight pixels. The fine resolution bytes are encoded so that, in conjunction with the double run length encoded three most significant bits of each pixel, (i) the entire six bits of one-fourth of the pixels, (ii) the most significant four bits of one-fourth of the pixels, intermediate between the six-bit pixels, and (iii) only the three most significant bits of one-half of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.