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ProPhoto RGB color space
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<h2 id="development">Development</h2> <p>The development of the ProPhoto RGB and other color spaces is documented in an article<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> summarizing a presentation by one of its developers Geoff Wolfe at <a href="/facts/Kodak/zMnK74Cp">Kodak</a>, currently senior research manager at Canon Information Systems Research Australia, at the IS&T/SPIE Color Imaging Conference in 2011. </p> <h2 id="encoding-primaries">Encoding primaries</h2> <table><tbody><tr><th>Color</th><th>CIE x</th><th>CIE y</th><th>CIE X</th><th>CIE Y</th><th>CIE Z</th></tr><tr><td>Red</td><td>0.734699</td><td>0.265301</td><td>0.79767</td><td>0.28804</td><td>0.00000</td></tr><tr><td>Green</td><td>0.159597</td><td>0.840403</td><td>0.13519</td><td>0.71188</td><td>0.00000</td></tr><tr><td>Blue</td><td>0.036598</td><td>0.000105</td><td>0.03134</td><td>0.00009</td><td>0.82491</td></tr><tr><td>White</td><td>0.345704</td><td>0.358540</td><td>0.96420</td><td>1.00000</td><td>0.82489</td></tr></tbody></table> <h2 id="viewing-environment">Viewing environment</h2> <ul><li><a href="/facts/Luminance/yAqK94ny">Luminance level</a> is in the range of 160–640 cd/m2.</li> <li>Viewing surround is average.</li> <li>There is 0.5–1.0% viewing flare.</li> <li>The adaptive <a href="/facts/White_point/MP9M3NmB">white point</a> is specified by the <a href="/facts/Chromaticity/eMDuJLsk">chromaticity</a> values for CIE <a href="/facts/Standard_illuminant/urST5Mz7">Standard illuminant</a> D50 ( x = 0.345704 {\displaystyle x=0.345704} , y = 0.358540 {\displaystyle y=0.358540} ).</li> <li>The image color values are assumed to be encoded using flareless (or flare corrected) colorimetric measurements based on the CIE 1931 <a href="/facts/Standard_colorimetric_observer/fzgwzV8V">Standard Colorimetric Observer</a>.</li></ul> <h2 id="encoding-function">Encoding function</h2> X R O M M ′ = I M A X ⋅ { 0 ; X R O M M < 0.0 16 ⋅ X R O M M ; 0.0 ≤ X R O M M < E t X R O M M 1 / 1.8 ; E t ≤ X R O M M < 1.0 1 ; X R O M M ≥ 1.0 {\displaystyle X'_{\mathrm {ROMM} }=I_{\mathrm {MAX} }\cdot {\begin{cases}0;&X_{\mathrm {ROMM} }<0.0\\16\cdot X_{\mathrm {ROMM} };&0.0\leq X_{\mathrm {ROMM} }<E_{t}\\X_{\mathrm {ROMM} }^{1/1.8};&E_{t}\leq X_{\mathrm {ROMM} }<1.0\\1;&X_{\mathrm {ROMM} }\geq 1.0\end{cases}}} <p>where </p> X = R , G , o r B {\displaystyle X=R,\,G,\,or\,B} <p>and </p> I M A X {\displaystyle I_{\mathrm {MAX} }} is the maximum integer value used in the encoding function (e.g. 255 for 8-bit configuration) <p>and </p> E t = 16 1.8 / ( 1 − 1.8 ) = 2 − 9 = 1 / 512 = 0.001953125 {\displaystyle E_{t}=16^{1.8/(1-1.8)}=2^{-9}=1/512=0.001953125} <h2 id="external-links">External links</h2> <ul><li><a href="https://www.color.org/ROMMRGB.pdf">Specification of ROMM RGB</a></li> <li><a href="https://www.color.org/chardata/rgb/rommrgb.xalter">Information page about ROMM RGB</a> including a downloadable ICC format profile.</li> <li><a href="https://luminous-landscape.com/understanding-prophoto-rgb/">Understanding ProPhoto RGB</a></li> <li><a href="http://www.naturephotographers.net/articles1203/mh1203-1.html">Color Spaces: Beyond Adobe RGB</a></li> <li><a href="http://www.outbackphoto.com/color_management/cm_06/essay.html">Why Use the ProPhoto RGB Color Space?</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Pointer, M. R. (1980). "The Gamut of Real Surface Colours. Color Res. Appl., 5". Color Research & Application. 5 (3) (published 2007-03-15): 145–155. doi:10.1002/col.5080050308. Retrieved 2021-04-19. <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/col.5080050308" target="_blank">https://onlinelibrary.wiley.com/doi/abs/10.1002/col.5080050308</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Jansen, Kid (2014-02-19). "The Pointer's Gamut - The coverage of real surface colors by RGB color spaces and wide gamut". TFT Central. Retrieved 2017-10-29. <a href="https://www.tftcentral.co.uk/articles/pointers_gamut.htm" target="_blank">https://www.tftcentral.co.uk/articles/pointers_gamut.htm</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>ISO (August 2012). "ISO - ISO/TS 22028-3:2012 - Photography and graphic technology — Extended colour encodings for digital image storage, manipulation and interchange — Part 3: Reference input medium metric RGB colour image encoding (RIMM RGB)". ISO. 2012. Retrieved 2021-04-19. <a href="/wiki/International_Electrotechnical_Commission" target="_blank">/wiki/International_Electrotechnical_Commission</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>International Imaging Industry Association (2002). "ANSI/I3A IT10.7466-2002 - Photography - Electronic still picture imaging - Reference Input Medium Metric RGB Color encoding (RIMM-RGB)". ANSI Webstore. Retrieved 2021-04-19. <a href="/wiki/International_Imaging_Industry_Association" target="_blank">/wiki/International_Imaging_Industry_Association</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Naty (2011-12-21). "Real-Time Rendering · 2011 Color and Imaging Conference, Part VI: Special Session". www.realtimerendering.com. Retrieved 2017-10-29. <a href="http://www.realtimerendering.com/blog/2011-color-and-imaging-conference-part-vi-special-session/" target="_blank">http://www.realtimerendering.com/blog/2011-color-and-imaging-conference-part-vi-special-session/</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> </ol>