[Openicc] Printing Plans GhostScript / sRGB / ICC

[Kai-Uwe Behrmann]

Am 02.03.11, 13:28 -0700 schrieb Chris Murphy:

> This can be done with CUPS PDF's job ticket info which is integrated in the PDF spool. I don't know how this is done for PostScript. But in any event, the job ticket info is really for CUPS. Not for downstream. So if it's communicated to CUPS, then it seems we need a pdftopdf to extract the job ticket info and form a proper PDF that communicates intent to Ghostscript (or whatever).
>
> Asking Ghostscript to honor platform specific job ticket info, I think, will cause problems. These documents really need to be self defining, and make it easy to produce documentation for so people know how this stuff works. Simplification is very important here.

I want to  second the last sentence. Ambiguity buys us only workarounds 
upon workarounds. The job ticket info for a "no colour management" flag is 
a additional path for the PDF standard specified one.


With the job ticket we could then recommend:
"The 'no colour management' flag is easy to use. Make sure it works in 
your environment. Check all components not to strip that accidentially. 
Each component might not know what the flag actually means. As well in 
case a PDF/X (A/E) in the pipe, the 'no colour management' flag might be 
ignored. So ask the PDF creator to avoid these PDF flavours. Make sure the 
basic colour space matches the device. If something goes wrong and you 
have embedded the flag correctly and avoided the mentioned PDF flavours, 
try to figure out where the flag might be stripped, create a patch to 
implement the desired behaviour and ask politely to include your changes 
in the upstream project."

Recommending the PDF inherent path reads like:
"To switch of colour management Use PDF/X (E/A) with DeviceXXX and a 
OutputIntent. The OutputIntent profile and the DeviceXX shall match the 
configured devices colour space. If you created a correct file 
and something goes wrong, submit a bug report."


Both recommendations cover requirements and potential workflow issues.


kind regards
Kai-Uwe Behrmann
-- 
developing for colour management 
www.behrmann.name + www.oyranos.org