Digital non-linear pre-emphasis/de-emphasis apparatus for eliminating noise components from video signals in a video signal processing system
US4849826A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 10, 1987 |
| Grant date | Jul 18, 1989 |
| Priority date | — |
| Expiry date | Nov 10, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/923
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital non-linear pre-emphasis/de-emphasis apparatus is arranged such that a frequency band of a high-pass filter for extracting a high frequency component signal of an input signal is varied according to the input signal by feeding back the output signal of the high-pass filter through a first non-linear input/output circuit. The first non-linear input/output circuit multiplies the output signal of the high-pass filter by a coefficient which is a function of the output signal of the high-pass filter to obtain a feedback signal. The output signal of the high-pass filter is also applied to a second non-linear input/output circuit which multiplies the output signal of the high-pass filter by a coefficient which is a function of the output signal of the high-pass filter. An output signal of the second non-linear input/output circuit is mixed with the input signal by an operation circuit to obtain an output signal which is non-linearly emphasized or de-emphasized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.