NTSC/PAL switchable video color decoder using a digital comb filter and method
US4766484A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1987 |
| Grant date | Aug 23, 1988 |
| Priority date | — |
| Expiry date | Apr 7, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/78
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus for and a method of decoding a video color signal provides a digital wide band luminance signal. An analog signal V1 representing the low band luminance component of a coded video color input signal Icv, is obtained at a first analog filter 1. An analog signal Yhc representing high band luminance and chrominance components is obtained at second means (5) which subtracts the first analog signal Y1 from a delayed input signal Icv. Signal Yhc is synchronously demodulated to provide (B-Y) and (R-Y) chrominance component signals U.sub.1, V.sub.1, which are digitized. Via digital delay means, single line delayed signals Yd1, U.sub.0, V.sub.0 and double line delayed signals U.sub.-1, V.sub.-1 are obtained. High band luminance signals Yu, Yv are then obtained as a function of at least two of the respective chrominance component signals U.sub.1, U.sub.0 and U.sub.-1 ; and V.sub.-1, V.sub.0 and V.sub.-1. These signals Yu, Yv are remodulated and combined to provide a digital high band luminance component signal Yh. Finally, by digitally summing the digital signals Yd1 and Yh a digital wide band luminance output signal Yd is obtained. Two different functions for obtaining the high ba…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.