[Openicc] Google Summer of Code 2009: Oyranos CUPS backend

[Kai-Uwe Behrmann]

Hello,

the CUPS backend needs to tell Oyranos, which PPD colour related entries 
a PPD has. These entries are used to select a meaningful user configured 
ICC profile.

Could you imagine a PPD entry, which solely lists all colour related 
entries? Something like:
*colourKeyWords: "ColorModel;StpColorPrecision;MediaType;StpQuality;Resolution;StpInkSet;StpInkType;StpBrightness;StpFineBrightness;StpContrast;StpFineContrast;StpSaturation;StpFineSaturationStpImageType"
Note this example is incomplete.

A disadvantage might by that it has to be included into every PPD. For a 
driver with a large number of supperted printers and hence many PPDs like 
the Gutenprint one, it would mean to repeat that stuff. The advantage is 
a included PPD entry would be very simple to parse along the CUPS 
delivered PPD.

Would this path be acceptable for foomatic, Gutenprint and hplib and 
other vendors?


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


Am 19.08.09, 11:59 +0200 schrieb Kai-Uwe Behrmann:
> Am 19.08.09, 11:16 +0200 schrieb Till Kamppeter:
>> Kai-Uwe Behrmann wrote:
>>> What I do not know is, how to distinct the colour related PPD options from
>>> the non relevant to make selection dependent on say "gamma" but not on
>>> "paper size". Would you know a way how to select ppd_attr_t attributes
>>> according to their influence on colour?
>>
>> Principally one cannot read from a PPD option whether it influences color or
>> not.
>
> This will it make harder to get PPD to ICC profile mapping outside of the
> CUPS cupsICCProfile scheme. The need of root access to do proper colour
> management is yet clearly a limit.
>
> On the other side Oyranos needs to know if a PPD option or attribute is
> relevant for colour or not to do CM configuration outside of the
> cupsICCProfile scheme.
>
> E.g. a user printing to remote printer or on a system without root rights
> she can not locally assign a ICC profile to a given PPD in the Oyranos
> DB and keep flexibility without complicated tweaking. But exactly that was
> the goal we where aiming at in this years GSoC projects.
>
>> ICC profiles can be associated to choices of up to three options, by default
>> to ColorModel, MediaType, and Resolution:
>>
>> *cupsICCProfile ColorModel.MediaType.Resolution/Description: "filename"
>> *cupsICCProfile RGB.GlossyPhoto.1200dpi/High-Quality Photo on Glossy Photo
>> Paper: "Acme-PhotoStar-RGB-GlossyPhoto-1200.icc"
>>
>> Instead of MediaType and Resolution two other options can be used with
>> definitions like:
>>
>> *cupsICCQualifier2: Quality
>> *cupsICCQualifier3: ImageType
>>
>> See http://www.cups.org/documentation.php/doc-1.4/spec-ppd.html
>
> Yes thats the next stage to support in order get the backend functional
> with cupsICCProfile.