Noise reduction apparatus for video signal
US4825289A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 10, 1987 |
| Grant date | Apr 25, 1989 |
| Priority date | — |
| Expiry date | Nov 10, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A noise reduction apparatus includes a vertical filter for extracting a component having a high vertical frequency from an input video signal, a two-dimensional filter for extracting a component having a low vertical frequency and a high horizontal frequency from the input video signal, a detector for detecting a vertical line image portion from output components of the vertical filter and the two-dimensional filter, and a controllable two-dimensional filter which suppresses a component having a high vertical frequency at the vertical line image portion according to a detection signal from the dector. By this apparatus, the noise superposed on the vertical line image signal is effectively reduced without deteriorating the vertical resolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.