RGB color spaces
From Wikipedia, the free encyclopedia
An RGB color space is any additive color space based on the RGB color model.
RGB is shorthand for Red, Green, Blue.
RGB is a convenient color model for computer graphics because the human visual system works in a way that is similar—though not quite identical—to an RGB color space. The most commonly used RGB color spaces are sRGB and Adobe RGB (which has a significantly larger gamut). Adobe has recently developed another color space called Adobe Wide Gamut RGB, which is even larger, in detriment to gamut density.
As of 2007, sRGB is by far the most commonly used RGB color space, particularly in consumer grade digital cameras, because it is considered adequate for most consumer applications, and its design simplifies previewing on the typical computer display. Adobe RGB is being built into more medium-grade digital cameras, and is favored by many professional graphic artists for its larger gamut.
RGB spaces are generally specified by defining three primary colors and a white point. In the table below the three primary colors and white points for various RGB spaces are given. The primary colors are specified in terms of their CIE 1931 color space chromaticity coordinates (x,y).
| Color Space | Gamut | White Point | Primaries | |||||
|---|---|---|---|---|---|---|---|---|
| xR | yR | xG | yG | xB | yB | |||
| ISO RGB | Limited | floating | floating | |||||
| Extended ISO RGB | Unlimited (signed) | floating | floating | |||||
| sRGB, HDTV (ITU-R BT.709-3) |
CRT | D65 | 0.64 | 0.33 | 0.30 | 0.60 | 0.15 | 0.06 |
| ROMM RGB | Wide | D50 | 0.7347 | 0.2653 | 0.1596 | 0.8404 | 0.0366 | 0.0001 |
| Adobe RGB 98 | CRT | D65 | 0.64 | 0.34 | 0.21 | 0.71 | 0.15 | 0.06 |
| Apple RGB | CRT | D65 | 0.625 | 0.34 | 0.28 | 0.595 | 0.155 | 0.07 |
| NTSC (FCC 1953) | CRT | Ill. C | 0.67 | 0.33 | 0.21 | 0.71 | 0.14 | 0.08 |
| NTSC (1979) (SMPTE C, SMPTE-RP 145) |
CRT | D65 | 0.63 | 0.34 | 0.31 | 0.595 | 0.155 | 0.07 |
| PAL/SECAM (EBU 3213, ITU-R BT.470-6) |
CRT | D65 | 0.64 | 0.33 | 0.29 | 0.60 | 0.15 | 0.06 |
| CIE (1931) | Wide | E | 0.7347 | 0.2653 | 0.2738 | 0.7174 | 0.1666 | 0.0089 |
Note that CIE 1931 (or CIE XYZ) is not an RGB color space.
[edit] See also
[edit] External links
- Susstrunk, Buckley and Swen. Standard RGB Color Spaces (PDF). Retrieved on November 18, 2005.
- ShootSmarter.com. sRGB vs Adobe RGB: The Truth. Retrieved on November 18, 2005. - a summary of the practical aspects of using the two spaces (requires membership - membership free if email provided.)
- Lindbloom, Bruce. RGB Working Space Information. Retrieved on November 18, 2005.
| Color space ■ Color models |
|---|
| RGB color spaces ■ RGB color model ■ CMYK color model ■ HSV color space ■ HSL color space ■ RYB color model ■ CIELAB (L*a*b*) ■ YUV for PAL television ■ YDbDr for SECAM television ■ YIQ for NTSC television |
