[Openicc] CC Profiles In X... Printer linearization

[Jan-Peter Homann]

Hello list
Currently I´m quite busy to to take care on long e-mail discussion. But 
as also ronald stated, the linearization is even as or more important 
than individual profiling.
 From my point of view, the most interesting approach for the 
linearization of digital printing systems is called G7, because it 
concentrates on a shared visual appearance for different printing 
technologies and media types.
Originally, it was developed for linearizing offset presses in the US, 
but it can easily be adapted to all kind of printing technologies incl. 
desktop inkjet printers.
A lot of technical informations and testcharts for the i1 can be 
downloaded from http://www.gracol.org/
As the G7 technology will also be described in an ISO technical report 
about calibration technolgies for printing systems, it can be 
implemented without the fear of licensing fees.

But as the US non profit organization http://www.idealliance.org has a 
trademark on G7, the term should not be referenced in applications 
without contacting IDEAlliance before.
They are quite open to all activities around G7 and it should be no 
problem to get the allowance to reference it in solutions for 
linearizing desktop inkjet printers.

OSS projects, which wan´t to avoid  best possible any kind of trademark 
issues can use of the term "near neutrals calibration" which will be 
used in ISO TC 130 technical report.

On the other hand, a project to implement G7 for desktop inkjet printers 
could may get some support from IDEAlliance in form of promotion on 
their website and in their newsletter which is worldwide quite important 
for a lot of professionals in the graphic arts.

As G7 or the near neutrals calibration approach concentrates on 
gradation for black and CMY and also for CMY gray balance, it can be 
easy combined with generic ICC profiles.

It would also be possible to create references for a visual 
linearization / calibration approach:
- The user prints out gray test patches (K and CMY) and compares it with 
a printed reference. The number of patches which matches best the 
reference will be typed in the linearization software and the printing 
system is linearized / calibrated by the eye. The production of the 
reference samples could be done on a inkjet printer, which is calibrated 
with an i1 pro.
So there is no big investment to do this.

If someone is interested to go further in this direction, I could give 
some input from the perspective of an colormanagement consultant. For 
doing some validation tests I have an Epson Photo R2400 here (and also 
Epson SP 3800 and SP 4800)

If You need direct contact to the G7 people, you can also contact me. 
But sometimes, I´m quite busy.

Regards
Jan-Peter


> On 1/16/08, Hal V. Engel <> wrote:
>
>   
>> In spite of how new color management is to open source systems I think that
>> there is actually a fairly large number of users relative to the total number
>> of users that own various types of measurement devices.  In part this is
>> because users of open source systems tend to be more technical than users of
>> commercial systems.   Because of this I think it would be possible to
>> organize an effort to create a repository for Printer profiles for these
>> systems and have a significant pool of volunteers with the equipment needed
>> to do the measurement work who could spread the work around.  But it would
>> take a significant effort to get this underway.
>>
>> Hal
>> _______________________________________________
>>     
>
>
>   


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