Method and apparatus for generating small, optimized color look-up tables
US6011540A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1997 |
| Grant date | Jan 4, 2000 |
| Priority date | — |
| Expiry date | Mar 28, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T11/001
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a computer graphics windowing system including a color map, a method for managing palette color value contents of the color map. Input color values are received. Error values between each input color value and each palette color value are used to determine a closest palette color value to each input color value. A list of input color values having largest error value distances to their respective closest palette color values is determined. A subset of this list is added to the color map to derive a modified color map. A color value metric process for determining an error value between each input color value and each palette color value comprises converting each input color value and each palette color value to a uniform color space. A lightness weighting constant is used to skew the error value in to be more strongly influenced by differences in lightness than by differences in chromaticity. A look up table having address spaces indexed by RGB index color values is generated. Each address space of the look up table is filled with a color map address of the closest palette color value to the respective RGB index color value referencing the address space.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.