Adobe RGB color space

The Adobe RGB color space is an RGB color space developed by Adobe Systems in 1998. It was designed to encompass most of the colors achievable on CMYK color printers, but by using RGB primary colors on a device such as the computer display. The Adobe RGB color space encompasses roughly 50% of the visible colors specified by the Lab color space, improving upon the gamut of the sRGB color space primarily in cyan-greens.

Specification

In Adobe RGB, colors are specified as triplets, where each of the R, G, and B components can have values between 0 and 1. When displayed on a monitor, the exact chromaticities of the white point , the black point , and the primaries [ etc.] are specified. Moreover, the luminance of the monitor should be 160 cd/m² at the white point, and 0.5557 cd/m² at the black point, which implies a contrast ratio of 287.9. The environment of the monitor is illuminated at 32 lx.

As with sRGB, the RGB component values in Adobe RGB are not proportional to the luminances. Rather, a gamma of 2.2 is assumed, without the linear segment near zero that is present in sRGB. The precise gamma value is , or 2.19921875.

The white point corresponds to D65. The chromaticities of the primary colors and the white point are as follows:

See also

References

• The AdobeRGB(1998) Specification, May 2005 (PDF)

External links

• Adobe Magazine discussion of the new format (PDF)
• Adobe RGB (1998) color image encoding