[argyllcms] Re: help with camera profile

  • From: Iliah Borg <ib@xxxxxxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sun, 22 Jul 2012 18:35:45 -0400

>> Yellow cast might be the result of wrong setting of the clipping in the 
>> converter as Nikolay suggested. 
> 
> I don't think this is the problem. I checked saturation with dcraw and
> the value set in the dcraw code is lower than the one of my camera.

Close to the saturation the sensor can be non-linear. That is especially the 
case when the cameramaker is after maximum well capacity. 

Camera needs to be linearized before profiling, especially when using 
matrix-type profiles with single gamma.

A question to Graeme if I may:
Is there a way to incorporate linearization curves into input profiles? colprof 
with a refine result as "-p" seems to produce good results only for output 
profiles. Inverting the sequence of ti3 files for refine does not help. The 
reason I ask is not only digital cameras, but scanning negatives as well. For 
negatives I obtain an L* -> L* table by measuring the densities on the film 
shot of the Kodak N2 target, and the reference L* values of the target are also 
known (and measured). The profile composed by refine is correct if used as a 
stand-alone.

--
Iliah Borg
ib@xxxxxxxxxxx




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