Quoting Elle Stone <ellest...@ninedegreesbelow.com>: > Standard RGB working spaces are defined by Red, Green, and Blue > primaries, a color space white point and a TRC that is the same in all > three channels, plus chromatic adaptation from the color space white > point to the profile illuminant.
Maybe this is what standard working space means to you, buy there is nothing in the ICC spec that refers to "workspace" profiles. What many image editing apps are actually using are oversimplified *display* profiles. Whilst this may work on some situations, the profiles were never intended for this purpose. Just to enumerate some issues the matrix-shaper sRGB has: - It has no intents - If we assume it works in relative colorimetric, then black scaling is wrong - If we assume it works in perceptual, then the gamut mapping is very poor (just clipping). - The black point is wrong in any case - The media white of sRGB *profile* is D65 and should be D50 - The chromatic adaptation tag is not there, so there is no way to discount the illuminant. - it is a V2 profile, not use perceptual reference medium gamut PRMG. - etc. ICC has addressed some of those issues: http://color.org/srgbprofiles.xalter But still, gamut mapping may be improved and I would like to see a floating point elements version, for example. Adobe RGB profile is almost same. > Do phrases like "legacy matrix-shaper profiles" and "only work with that > very old profiles" - mean that using standard RGB working spaces (and > linear gamma versions of same) is outdated or substandard for RGB > digital painting or image editing, such as one might do using Krita, > GIMP, or PhotoShop? sRGB space is an spec: IEC 61966-2-1, This is not outdated. The profile "sRGB Color Space Profile.icm" is a very old profile with many problems. This is outdated. Linear versions are just different color spaces. The spec does not talk about "linear sRGB" there is no such thing. This is something that uses D65 as white point, gamma 1 and Rec709 as primaries, but this is not sRGB. > is there a way to retrieve these parameters from the profile and then > use them to generate a point curve approximation that can be plotted? lcms has those functions to do that: cmsGetToneCurveEstimatedTableEntries(const cmsToneCurve* t); cmsGetToneCurveEstimatedTable(const cmsToneCurve* t); Regards Marti ------------------------------------------------------------------------------ _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
