RGB color space
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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 than sRGB. Adobe has recently developed another color space called Adobe Wide Gamut RGB, which is even larger, in detriment of gamut density.
As of 2004, 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 also being built into more medium-range digital cameras, and is favored by many professional graphic artists.
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 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 | 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 | 0.070 |
| NTSC RGB | CRT | Ill. C | 0.67 | 0.33 | 0.21 | 0.71 | 0.14 | 0.08 |
| EBU RGB (CCIR 601) | CRT | D65 | 0.64 | 0.33 | 0.29 | 0.60 | 0.15 | 0.06 |
| ITU-R BT.709 | CRT | D65 | 0.64 | 0.33 | 0.30 | 0.60 | 0.15 | 0.06 |
| CIE RGB (1931) | Wide | E | 0.7347 | 0.2653 | 0.2738 | 0.7174 | 0.1666 | 0.0089 |
See also
External links
- Susstrunk, Buckley and Swen, "Standard RGB Color Spaces" (PDF) (http://ivrgwww.epfl.ch/publications/sbs99.pdf)
- sRGB vs Adobe RGB: The Truth (http://www.shootsmarter.com/infocenter/wc025.html) - a summary of the practical aspects of using the two spaces
- A paper comparing RGB color spaces (http://lcavwww.epfl.ch/~sabines/127.pdf) - an Adobe PDF document
- RGB Working Space Information (http://www.brucelindbloom.com/index.html?WorkingSpaceInfo.html)