[Openicc] Gutenprint and OpenICC

[Jan-Peter Homann]

Hello alastair and others
I´m bringing back this private discussion to OpenICC, because I think it 
belongs here...
I agree to your proposal. (at the end of this e-mail)

But what I still havn´t understand:
- How does pdftoraster interacts with PPD and cupsICCprofile ?
(The user chooses in the printing UI a mediasetting provided by the PPD. 
This triggers cupsICCprofile. But how does the pdftoraster gets the 
information from cupsICCprofile ?

- How to update mediasettings in the printing UI ?
 From my knowledge, the mediasettings in the printing UI are dependent 
from the PPD. If we update mediasettings, we have to update the PPD 
first, before it will visible in the printing UI, correct ?

- how to specify a rendering intent in the printing UI ?
cupsICCprofile provides some mechanism, to specify a profile for 
mediasetting in the cups environment. But I don´t see how a rendering 
intent can be specifies in the CUPS environment ?

kind regards
Jan-Peter


Am 08.03.11 01:19, schrieb Alastair M. Robinson:
> Hi,
>
> I don't know about you guys, but I'm finding the OpenICC list 
> depressing reading at the minute - there's an undercurrent of politics 
> and hostility, not to mention conflicting philosophies, that's getting 
> in the way of getting anything done.
>
> The more I think about it, the more I think the whole 
> matching-print-settings-to-profiles thing is coming at the problem 
> from the wrong angle, and I think there's a way in which Gutenprint 
> can solve the problem without getting in the way of the OpenICC guys' 
> solution, if they ever manage to create one.
> For Gutenprint's part, I think all we need is user-definable media types.
>
> These would be the things Edmund has referred to as "prosets" - they 
> would be a bundle of settings and an associated ICC profile.  They 
> would be installed server-side (and yes, that would require admin 
> rights), at which point they would appear in the PPD as a new media 
> type.  The ICC profile's name would appear in the PPD keyed to that 
> media type.
>
> For this to work we would need:
> * A print quality setting that amounts to "Whatever is suitable for 
> the current media type" - this would either mean adding a new setting 
> (which would need to be the default), or redefining "Standard".
> * Cascadable XML files, so that for instance, a newly-defined 
> 7DayShopSatin.xml can reference the values from "Premium Luster Photo 
> Paper" before overriding with any adjusted settings.
>
> If we can get that much working, the rest's not Gutenprint's problem, 
> and enough already exists that we would then have a viable 
> colour-managed print pipeline which would be better than a pure 
> sRGB-based one.
>
> Applying the ICC profile appears to be a solved problem, since there's 
> a colour-managed pdftoraster based on Poppler (which doesn't work too 
> well yet, but it probably will in time), and a similar 
> Ghostscrip-based pdftoraster should be pretty trivial too.
>
> Users who wish to override settings can still do so via PPD options. 
> Since the actual colour conversion's done by pdftoraster, it can be 
> disabled or overridden; thus, users without permission to install 
> systemwide profiles could use colord to set a new profile for their 
> own use.
>
> The downside, of course, is that these custom media types would be 
> tied to a specific resolution (you could pick a different one of 
> course, but the profile wouldn't be valid) - but then as soon as an 
> ICC profile's involved, you need to keep everything fixed as much as 
> possible anyway.
>
> Anyhow, just a few thoughts on the subject - comments welcome. :)
>
> All the best
> -- 
> Alastair M. Robinson
>


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