[Openicc] Printing Plans GhostScript / sRGB / ICC

[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.


Chris

On Mar 2, 2011, at 1:22 PM, Jan-Peter Homann wrote:

> Hello Chris and all,
> I think having metadata in the spool file for transporting informations, which are not part of the PDF but needed for pdftoraster are quite useful.
> 
> E.g., if I want to print in draft mode and do screening in gutenprint, it would be enough to render a bitmap with 360 DpI in GhostScript. Other usescases would be e.g. 720 DpI and highest quality 1440 DpI.
> 
> Such information have not a standard place in the PDF, but they are useful as an flag like "don´t colormanage"
> Also when the user specifies "Duplex Printing", such Metainformation is specified in the moment when the spool file is created and must be passes through pdftoraster reach the driver (e.g. Gutenprint).
> 
> So have a look how CUPS is handling such metada / jobticket and define here the flag "don´t colormanage"
> 
> Best regards
> Jan-Peter
> 
> 
> 
> Am 02.03.11 19:36, schrieb Chris Murphy:
>> 
>> On Mar 2, 2011, at 11:18 AM, Jan-Peter Homann wrote:
>>> 
>>> The discussion on how to handle printing DeviceXXX spool data without applied "sRGB to printer profile transformtion" is in my eyes a little bit strange.
>>> 
>>> We only have to take care, that the pdftoraster filter can be easily configured to print straight forward. What should not be complicated both for GhostScript and poppler.
>>> 
>>> If we are able to transport printer specific options like e.g. duplex options beside the PDF spool file, we should also be able to transport a flag for turning colormanagement of in pdftoraster filter beside the PDF spool file. I don´t see any need to integrate a "color management of flag" directly into DeviceXXX PDF files.
>> 
>> How do you communicate to pdftoraster when /DeviceRGB means sRGB vs actually meaning /DeviceRGB?
>> 
>> For a PDF spool file, you can do this with /DeviceRGB without OutputIntent, vs /DeviceRGB with OutputIntent.
>> 
>> For PostScript you don't have OutputIntent, so how do you differentiate for PostScript?
>> 
>> 
>> Chris Murphy
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> 
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