[Openicc] Printing targets: App or driver ?

[Kai-Uwe Behrmann]

Am 16.05.11, 10:10 +0200 schrieb Jan-Peter Homann:
> Reading the discussion about print targets, i missed some points:
>
> 1) CMYK Colorspace for profiling Gutenprint:
> I strongly recommend to profile CMYK+X printers only with CMYK (+X) 
> targets. Dealing with the relation of CMY to K is much better handled 
> inside the printer ICC profile, than with a internal Gutenprint 
> RGB_to_CMYK conversion and an RGB-printer-profile on the top.

That reads quite logical. Assuming mostly experts have the needed 
measurement equipement that makes sense.

> So it doesn´t make sense to offer in the driver a option for printing 
> testcharts from an application if the application / printspool toolkit 
> can´t handle CMYK files.
>
> 2) Necessary tasks for dealing with testcharts, driver settings and 
> printer profiles
> - a testchart must be printed with a carefully choosen setting for 
> printer / media / quality setting
> - after printing the testchart and calculating the profile, we need a 
> save way to link printer-profile and correct driver setting

> - new combinations of a printer profile and driver setting should be 
> easily and reliable installed by users, which don´t know anything about 
> colormanagement and printer profiles.

exactly

> 3) How to realise such functionalities:
> We may could implement the functionalities for:
> - testchart printing
> - calling a profiler toolkit
> - linking printer profile and driver settings
> - importing printer profile with linked driver setting
>
> as a combination of g-c-m or Oyranos with CPD
>
> - choosing a driver setting is done into CPD
> - sending a CMYK testchart directly to the printer is done from g-c-m or 
> Oyranos through CPD directly to restertogutenprint or rsatertovendorXY
> - measuring the testchart and calling the profiling toolkit is done with 
> g-c-m or Oyranos using the Argyll libs for driving spectrophotometers or 
> calling Argyll colproof
> - linking printer profile with the driver settings is done in g-c-m or 
> Oyranos with e.g usage of Argyll ICC-lib, which provides already the 
> addition to new tags to an existing printer profile
> - importing a new printer profile with embedded driver settings is 
> handled in CPD
> - If the user chooses in CPD a new driversetting / ICC, the profile is 
> communicated through colord or Oyranos to pdftoraster
> - pdftoraster embedds the profile into the raster file for 
> rastertogutenprint or rastertovendorXY
> - rastertogutenprint or rastertovendorXY extracts from the embedded 
> printerprofile the driver settings and prints the rasterfile.
>
> Richard:
> - Would this suggestion work with current g-c-m / colord architecture ?
>
> Kai-Uwe:
> - Does this fit into your concept for an Oyranos based print workflow ?

Generally yes. However Oyranos has itself no profiling capabilities at 
this time. What it can do already is, embedding driver settings into ICC 
profiles for monitors, and it is planned and partitial implemented to 
extent this embedding to other device classes too.

The pdftoraster and rastertovendorXY stage reads reasonable. But I do not 
know of the CUPS and pdftoraster/rastertovendorXY constraints in this 
regard.

> Michael Sweet:
> - Are there any security issues in the described workflow ?

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