[Lcms-user] css-color-hdr and HDR eotfs (Jzazbz and ICtCp)

[Wolthera <gri...@gm...>]

hey,

I was reading the css-color-hdr draft [1], and it contains a few
unusual colorspaces.

Now, as far as I understand it, the only way to have an ICC spec
conformant icc profile for Rec 2100 is by using LUTs, because the PQ
and HLG eotfs cannot be described by the formulas in the ICC specs
[2]. But at the least it is possible.

But the draft also specifies a Jzazbz colorspace (which seems to be
L*a*b*, except L* is replaced with the PQ-encoded Jz) as well as ICtCp
[3].

Is it possible to have icc profiles, or a littleCMS workflow for
these? I'm not too familiar with the icc profile spec, so I don't know
what the exact rules are for these big encompassing colorspaces, and I
think it'd be valuable for W3C to have the feedback if these
colorspaces are not possible for a variety of open source software.

[1] - https://drafts.csswg.org/css-color-hdr/
[2] - https://github.com/mm2/Little-CMS/issues/217
[3] - https://en.wikipedia.org/wiki/ICtCp
-- 
Wolthera