Noise reduction in video signals
US5557340A · kind A · utility
28Cited by
10References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 28, 1994 |
| Grant date | Sep 17, 1996 |
| Priority date | — |
| Expiry date | Nov 28, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/69
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a high definition flying spot telecine, noise from photomultiplier tubes and afterglow correctors reaches unacceptable levels at high frequencies. The circuit illustrated applied a conventional gamma correction to low frequency components (at 32) but applies a non-linear characteristic to the high frequency components (at 36). The characteristic is chosen to provide the optimum noise performance for positive or negative film. The two parts of the signal are then recombined by adders 40. High frequency processing is carried out on a multiplex of the R, G and B components to reduce complexity (at 16).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.