[Openicc] Gutenprint and OpenICC

[Alastair M. Robinson]

Hi :)

On 09/03/11 08:21, Jan-Peter Homann wrote:

> I´m bringing back this private discussion to OpenICC, because I think it
> belongs here...

OK

> 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 ?

I've just checked the source of the about-to-be-released pdftoraster in 
Ubuntu, and it seems pdftoraster has to use the libcups helper functions 
to loop through the cupsICCProfile definitions in the PPD, comparing 
their selectors with the print job's settings.

That seems ripe for a helper function in its own right to me, but 
anyhow, an existing implementation exists.

> - 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 ?

Yes, the PPD would have to be regenerated to account for new media types 
becoming available (or new prosets being installed, if they're 
implemented in a different manner).  I don't know how easy or difficult 
that would be.

> - how to specify a rendering intent in the printing UI ?

It would either have to be a PPD option, or simply a fixed default (in 
which case, *please* Perceptual, not Rel Col, so we can make use of the 
gamut mapping in Argyll's profiles), and then rely on Ghostscript and/or 
Poppler correctly handling rendering intents later on.

All the best
--
Alastair M. Robinson