Method and apparatus for correcting color difference signals
US6137540A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1999 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Aug 13, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/77
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention relates to the color matching function used in connection with the luminance or white stretch function in a television video processor. Automatic adjustment in the amplitude of the color difference signals is provided to compensate for the effect of the stretch of the luminance signal in a provision called color matching. The general principal of color matching being, any percentage change in the amplitude of the luminance signal due to the white stretch effect, must be balanced by the same percentage changes in the color difference signal so that the ratio of the color signals can be maintained after matrixing. This accomplished by compensating the color difference signals by a varying amount that decreases with increasing the input luminance signal level when the level of the input luminance signal is above said selected threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.