Hi Richard, This is from more than 5 years, but still valid and very good. It answers many of your questions.
http://www.poynton.com/GammaFAQ.html Regards Marti El 18/01/2013 18:58, Richard Hughes escribió: > Hey all, > > I've had a chance to look more at the problem of display gamma > recently. It seems there is quite a lot of misinformation out there, > and very little in the way of standards that are actually applicable > to the technology we have now. Theory is diverging from practise in a > number of areas, for instance we calibrate to gamma 2.4 to adapt for > viewing conditions in Linux, and people are calibrating to gamma 2.2 > in Windows when using the X-Rite tools. > > I'm wondering about the basics of what gamma is and also how to > measure it. Some of the questions I'm asking myself: > > * on real life hardware, can we assume gamma_red == gamma_blue == gamma_green? > * how do we measure gamma given there's an offset at zero for anything > other than LED displays - pretending the backlight is zero and > offsetting everything to that seems a giant hack given our perception > of light isn't linear. > * roughly how many points does it take to calculate the gamma assuming > the hardware is well behaved (e.g. monotonic) -- three seems the > obvious answer, but the backlight at 0,0,0 and measurement accuracy > makes that tricky. > * how does the 2.4 v.s. 2.2 gamma adaption for viewing conditions > work? Is that a function of the luminance of the room, in which case > we should probably measure ambient first and do something more > technical than += 0.2. > > I can't find much up-to-date technical literature on display gamma > (anything written in the last 5 years) so if anybody can point me at > anything in Amazon or a research journal that a human being could > understand I'd appreciate it. > > Thanks, > > Richard. > > ------------------------------------------------------------------------------ > Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and > much more. Get web development skills now with LearnDevNow - > 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. > SALE $99.99 this month only -- learn more at: > http://p.sf.net/sfu/learnmore_122812 > _______________________________________________ > Lcms-user mailing list > Lcms-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/lcms-user > ------------------------------------------------------------------------------ Master HTML5, CSS3, ASP.NET, MVC, AJAX, Knockout.js, Web API and much more. Get web development skills now with LearnDevNow - 350+ hours of step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122812 _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
