Gradation correction method and device
US5661575A · kind A · utility
33Cited by
11References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1994 |
| Grant date | Aug 26, 1997 |
| Priority date | — |
| Expiry date | Dec 29, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/83
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The gradation correction device includes a luminance signal convertor to generate a luminance signal from the input R, G, B signals, a correction coefficient calculator which calculates the ratio to the luminance signal of the luminance signal after gamma correction to the predetermined gradation characteristics, and a multipliers to multiply the output from the correction coefficient calculator by each of the R, G, and B input signals. When the gradation correction is applied, effective brightness adjustment can be applied with no change in hue and saturation and without exceeding the dynamic range of a device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.