Video signal color correction based on color hue
US5436673A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 1994 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Feb 16, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/643
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Memories are provided for correction signal values respectively for a hue signal, a saturation signal and a luminance signal derived from a digital color television signal. Each of the memories consists of two memory units which are alternately used for storing new correction signal values and for reading out previously stored correction signal values. The corrected signal values are modified by a key signal, if present, in each case and are then supplied to calculation circuits to each of which a signal derived from the saturation signal is applied. The resulting fully corrected hue and saturation signals are converted back into color difference signals, but the finally corrected luminance signal requires no conversion. The raw correction signal values are supplied from a computer into which control magnitudes can be entered to produce them. These control magnitudes can be used to define corner points of a deflected line function from which the correction signals are derived. Monitors and cursors are used to facilitate correct entry of control magnitudes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.