Adobe RGB color space: Difference between revisions

| image = CIExy1931CIE1931xy AdobeRGB.pngsvg

| caption = The [[CIE 1931 color space#CIE xy chromaticity diagram and the CIE xyY color space|CIE 1931 ''xy'' chromaticity diagram]] showing the primaries of the Adobe RGB (1998) color space. The [[CIE Standard Illuminant D65]] [[white point]] is shown in the center.

The '''Adobe RGB (1998) color space''' or '''opRGB''' is a [[color space]] developed by [[Adobe Systems|Adobe Systems, Inc.]] in 1998. It was designed to encompass most of the colors achievable on [[CMYK]] color [[color printing|printers]], but by using [[RGB color model|RGB]] [[primary color]]s on a device such as a [[computer display]]. The Adobe RGB (1998) [[color space]] encompasses roughly 5030% of the [[visible spectrum|visible colors]] specified by the [[CIELAB color space]] – improving upon the [[gamut]] of the [[sRGB]] color space, primarily in cyan-green [[hue]]s. It was subsequently standardized by the [[International Electrotechnical Commission|IEC]] as IEC 61966-2-5:1999 with a name opRGB (optional RGB color space) and is used in [[HDMI]].<ref name="iec-standard" />

In Adobe RGB (1998), colors are specified as [''R'',''G'',''B''] triplets, where each of the ''R'', ''G'', and ''B'' components have values ranging between 0 and 1. When displayed on a monitor, the exact [[chromaticity|chromaticities]] of the reference [[white point]] [1,1,1], the reference black point [0,0,0], and the primaries ([1,0,0], [0,1,0], and [0,0,1]) are specified. To meet the color appearance requirements of the color space, the [[luminance]] of the monitor must be 160.00 [[candela|cd]]/m² at the white point, and 0.5557&nbsp;cd/m² at the black point, which implies a [[contrast ratio]] of 287.9. Moreover, the black point shall have the same chromaticity as the white point, yet with a luminance equal to 0.34731% of the white point luminance.<ref name = AdobeRGBColorImagingEncoding>{{cite techreporttech report |url = http://www.adobe.com/digitalimag/pdfs/AdobeRGB1998.pdf |title = Adobe RGB (1998) Color Image Encoding |publisher = Adobe Systems Incorporated |date = 13 May 2005}}</ref> The ambient [[illuminance|illumination]] level at the monitor faceplate when the monitor is turned off must be 32 [[lux|lx]].

As with sRGB, the ''RGB'' component values in Adobe RGB (1998) are not proportional to the luminances. Rather, a [[gamma correction|gamma]] of approximately 2.2 is assumed, without the linear segment near zero that is present in sRGB. The precise gamma value is 563/256, or 2.19921875. In coverage of the [[CIE 1931 color space]] the Adobe RGB (1998) color space covers 52.1%.<ref name=InformationDisplayDecember2012SuperHi-Vision>{{cite journal |lastlast1 = Yamashita |firstfirst1 = Takayuki |last2 = Masuda |first2 = Hiroyasu |last3 = Masaoka |first3 = Kenichiro |last4 = Ohmura |first4 = Kohei |last5 = Emotot |first5 = Masaki |last6 = Nishida |first6 = Yukihiro |last7 = Sugawara |first7 = Masayuki |date = November–December 2012 |title = "Super Hi-Vision" as Next-Generation Television and Its Video Parameters |url = http://informationdisplay.org/Portals/InformationDisplay/IssuePDF/12_2012.pdf |journal = Information Display |publisher = Society for Information Display |volume = 28 |issue = 11 & 12 |pages = 12–17 |doi = 10.1002/j.2637-496X.2012.tb00565.x |s2cid = 86626642 |access-date = 1 December 2013 |archive-url = https://web.archive.org/web/20150420223449/http://informationdisplay.org/Portals/InformationDisplay/IssuePDF/12_2012.pdf |archive-date = 20 April 2015 |url-status = dead }}</ref>

*[https://web.archive.org/web/20050505000309/http://www.adobe.com/products/adobemag/archive/pdfs/98auhtbf.pdf ''Adobe Magazine'' discussion of Photoshop 5.0’s0's new RGB working spaces]