Wayland color management

[dutch_wolf]

@Dmitry_Kazakov

Yes, unless ICC is the only means of describing color, then yes, HDR can be implemented quite easily. Though the devil hides in details: there is no commonly standard for describing HDR color Microsoft used enum tags for that, which is extremely bad: one cannot choose a custom color space for the buffer. There is even no tag for passthrough mode ( DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709 is technically a pass-though, because DXGI does no color management after compositing).

Well we both know that ICC is not the only way to describe color (just see OpenColorIO for on different example). Note that I don’t think we should use any form of ICC profile to communicate with the compositor (with maybe the exception of communicating the display profile of the ‘primary’ screen to an advanced application and even that could be done by defining a ‘display’ tag + something like colord to query the profile)

So I think we should define a set of tags, although I don’t think that hard coding the meaning of these (and number) is a good idea since that is one way to end up in the Windows situation (not flexible enough)

EDIT: Not communicating with ICC profiles does NOT mean that the compositor itself can’t implement the proposed workflow with LCMS internally (in whole or in part) it just means we need an other way (possibly out of bound of wayland, maybe in a spec document) to communicate the colorspace information. It also does NOT mean that the compositor isn’t color managed.

PS. Sorry for the double negatives in the edit