Color gamut and luminance matching techniques for image display systems
US6388648B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 1999 |
| Grant date | May 14, 2002 |
| Priority date | — |
| Expiry date | Sep 8, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3182
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An LCD projection unit employs a luminance and color balance system employing an LCD array characterization lookup table storing multiple sets of luminance and gamma correction values that are user selectable to control luminance and color balance. The lookup table values are determined by measuring the transfer function of the LCD array in the projection unit for each of a set of red (“R”), green (“G”), and blue (“B”) input data values, converting the resulting S-curve responses to corresponding sets of gamma responses and scaling the gamma responses to generate multiple R, G, and B families of luminance and gamma corrected values. Color balance is adjusted by selecting the particular R, G, and B families of luminance and gamma corrected values that cause the LCD projection unit to match a predetermined ratio of R, G, and B luminance values. Luminance is adjusted by selecting sets of families of R, G, and B, luminance values that maintain the color balance ratio while causing the LCD to transmit the desired overall luminance.The primary colors are adjusted by a method of color mixing implemented by a mathematical matrix algorithm that generates …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.