From: Simon Leibowitz
(clip)
I can find no file called sRGB ICE61966-2.1 in any system profile folders (OSX), so what is it, where's it coming from, should I care and which should I convert too?
I'll piece a little history I've gathered over the years for you...though I can't vouch for 100 percent accuracy in who did what to whom and what to where, this will give you the general ghist...
Profiles have both an external and internal names.Some application menus reveal the internal name (like PhotoShop), others view the external. It's a safeguard to keep users from altering some automated features in applications which look for certain naming conventions and/or types in their profiles.
sRGB ICE61966 is the internal name for the 3144 kbyte sRGB version standardized by Hewlett_Packard and Microsoft which was implemented in the ICM-2 color platform beginning in Windows 98. The most unique difference from the smaller current sRGB Profile being it uses older (and duplicate) tags and also 1024-point curves to describe it's matrixes. Most often you will find this (sRGB ICE61966-2.1 and other older versions) called sRGB Color Space Profile.icm (with or without suffix) on your system. I keep the one with the highest version number (2.1) and toss the rest to avoid confusion, because of folks like Kodak who just couldn't make up their mind...
Kodak implemented it's own sRGB back in 1996 in the form of sRGB.pf which uses a 5000k white point in order to be in sync with the d50 icc standard pcs white point conversion space. Around the same time it also implemented an sRGB (Kodak sRGB.icm and later sRGB.icm) with d65 gamma 1.8 matrix. Then a d65 gamma 2.2...and so on...Each for pretty much the same use in one application or the other. Confusing. When HP and Msoft jumped on standardizing Kodak eventually came on board and stuck to one format.
The progression of version types of sRGB brings it up to this date where you will find smaller, sleeker (1076 [2002] and 640 [2000] kbyte) matrix profiles based on gamma 2.2 curves. Usually these are simply called sRGB Profile (with or without suffix) and are a smoother transition for conversion space calculations. Interestingly enough, MacOSX users can inspect their own GenericRGB.icc system profile and find it contains many if not all the same characteristics of the current sRGB Profile. They each have 6600k white points, 2.2 gamma curves...etc.
If you would like to know some of the history, or perhaps build your own sRGB Profile, (I'm kidding...but not really) there is an excellent history paper pdf somewhere out there by Mary Nielsen and Michael Stokes of Hewlett-Packard Company, written around 1997 or 1998...which also contains the math required to live up to the bare requirements of the sRGB standard.
;0)
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