[Openicc] GoSoC 2011: CPD and Color Management

Graeme Gill graeme at argyllcms.com
Tue May 3 18:52:20 PDT 2011

edmund ronald wrote:
>   However I do think ink settings ALSO need to be able to exist without
> the profile since the ink settings precede the profile, and since it
> is extremely advantageous to be able to adopt the ink settings from
> some known paper as a quick starting point to work with another paper.
> Ink settings, as we agree do precede profiles, and therefore need to
> be able to exist and be invoked independently of profiles.

Yes. Such a format is needed anyway, to communicate the settings
between the print system and the user and or profiling software,
so that they can be embedded in the profile.

Note that a print system mechanism to enable or disable calibration
and separation is also needed to support print calibration.

In general for something like an inkjet printer with light & dark inks
there are four (reasonably distinct) printer states:
* raw with setting adjustments:
     Raw response of the physical color channels. There are still
     resolution, dot size and screening settings, plus a
     range setting (maximum per color value) involved.

     This state is used so as to be able to determine these settings,
     as well as determine the light and dark channel crossovers.

* separated and adjusted
     The dot level settings are set, and the light and dark channels
     have been combined and crossed over to create the set of
     logical device color channels. There are settings and/or tables
     that have been created to do this.

     This state is used to create calibration curved.

* calibrated, separated and adjusted
     The logical device color channels have had calibration
     curves applied to them.

     This state is used to create profiles.

* Profiled, calibrated, separated and adjusted
     The device ICC profile is used to convert incoming
     colorspaces to the devices colorspace.

     This state is the normal end user printing state.

To setup a printer, you need access to all of these states, not just
profiled/not profiled.

Graeme Gill.

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