Bandwidth compression system and method
US3950607A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1973 |
| Grant date | Apr 13, 1976 |
| Priority date | — |
| Expiry date | Apr 30, 1993 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/66
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus is disclosed for converting a wide-bandwidth signal to a narrow-bandwidth signal, the disclosed method and apparatus being particularly well suited for converting a wide-bandwidth real-time television signal to a narrow-bandwidth signal. A sampled video signal is coupled to an analog-to-digital converter which converts the amplitude of each sampled element to a binary code word having a predetermined number of bits. The binary code words are then written into a buffer storage element controlled by a clock switching device and later clocked out of the buffer storage device at a clock rate less than the input rate with the output from the buffer storage device being coupled to a digital-to-analog converter whose output is an analog signal with the same amplitude variations as the sampled video signal but with a time base stretched out by a predetermined factor. The field, either odd or even interlace, from which the sampled video signal was taken is identified by ascertaining the location of the horizontal signal pulses relative to the vertical signal pulse, and this field index may then be used to code the output narrow-bandwidth video signal. Another embodime…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.