Adaptive anti-crosscolor notch filter for SECAM encoder
US6160588A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1998 |
| Grant date | Dec 12, 2000 |
| Priority date | — |
| Expiry date | Oct 21, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N11/183
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A luminance notch filter for preventing color crosstalk adaptively attenuates a SECAM luminance signal depending on the strength of the luminance signal using digital filtering techniques. The adaptive luminance notch filter includes a bandpass filter centered at the chrominance band that is operative to receive the input luminance signal and provide a bandpass filtered luminance signal. The bandpass filtered luminance signal is multiplied by a gain factor and the multiplied luminance signal is subtracted from the input luminancee signal to provide a notch filtered luminance signal. A detector coupled to the bandpass filter output detects the signal strength of the bandpass filtered luminance signal and the gain factor is adapted in accordance with the detected signal strength. The bandpass filter comprises an infinite impulse response (IIR) filter that is preferably an all-pole IIR filter of at least 3.sup.rd order.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.