- From: Mike Bremford via GitHub <sysbot+gh@w3.org>
- Date: Tue, 31 Mar 2020 18:47:40 +0000
- To: public-css-archive@w3.org
Yes, exactly. When you create your N-color ColorSpace, you name all the inks. If your device has all those inks available¹, it will use them as specified. If not, the fallback is there to give you an approximation so you can render it as best as you can, but the fallback isn't used for anything else. I keep using "Pantone Reflex Blue C" for my examples because it, too, is notoriously difficult to reproduce with process CMYK (as you point out, if it wasn't, you wouldn't need it). So that single spot color is entirely defined by a) its name and b) a best-effort CMYK approximation. The "Device N" spaces are identical, just with more than one ink. I'll scare both of us if we go much further than the above, but - as you brought it up - in your example going from FOGRA51 to FOGRA55 I understand you'd probably use an "NChannel" DeviceN rather than basic DeviceN in PDF, as you would only need to simulate 3 of the inks. But I'm hitting the limits of my knowledge here, and I'm not trying to reinvent the whole PDF color model (shudders). If we can get the same basic concepts as PDF in place, it can be expanded if required - and what's here is enough to convert any color in this model to sRGB with reasonable fidelity. [1] qualifying this by saying I don't deal with the printing side at all, so know little of translating a PDF to paper. For PDF-people, what I'm describing is basic "DeviceN" colorspaces with linear tint transforms. Non-linear blends, NChannel, spectral information etc are not part of this proposal. -- GitHub Notification of comment by faceless2 Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/2023#issuecomment-606806047 using your GitHub account
Received on Tuesday, 31 March 2020 18:47:42 UTC