Digital comb filtering for PAL television signals
US4399454A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1980 |
| Grant date | Aug 16, 1983 |
| Priority date | — |
| Expiry date | Jul 16, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/78
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for comb filtering a type television signal is described. Preferably, the television signal is digitized by sampling it at an even multiple of its chroma subcarrier frequency, thereby to convert the television signal to a series of digital signals representative of discrete picture elements. The value of each such digital signal is indicative of the value of the luminance component and the value of the amplitude and phase of the chroma component of its associated picture element. The phase of the chroma component of a reference picture element is changed by combining and averaging stored digital signals associated with selected picture elements whose chroma component is of the desired phase and which, in combination, cancel out luminance components. Preferably, a resultant luminance signal is also generated by combining and averaging stored digital signals associated with selected picture elements so as to cancel out their chroma components, and the resultant luminance signal is combined with the phase-changed chroma signal to develop a final signal whose chroma component is of the desired phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.