[Digikam-users] camera ICC

[Elle Stone]

This was posted to the digikam mailing list recently:

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I've followed this instructions: 
http://ninedegreesbelow.com/photography/well-behaved-camera-profile.html 
but got strange results.

In short:
1)I've take a shoot of IT8.7/2 target
2)using DigiKam converted RAW to TIFF using 16bit color depth. All the 
rest is disabled or set to default values.
3)using  ArgyllCM  i've created icc profile.

Then if I apply this icc for converting RAW images the results looks 
like "losing contrast".

best regards,
Kostya.

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Hi Kostya,

AFAIK, the digiKam raw processor can't actually output a linear gamma 
raw color image. Rather the raw color image that digiKam outputs already 
has a roughly gamma=2.2 tone curve applied to it.

I made a note of this issue with digiKam at the bottom of section D4 in 
this article: 
http://ninedegreesbelow.com/photography/camera-profiles-applied.html#lut-profiles-vs-matrix-profiles

I also mentioned the problem in this article: 
http://ninedegreesbelow.com/photography/linux-raw-processor-review.html#radiometric

I should put a similar note in the article you were following, so my 
apologies! Anyway, try using the colprof parameter "-aG" or "-aS" 
instead of "-am".

If you send me your ti3 file and your camera input profile, I can check 
and see what actually happened.

Best regards,
Elle Stone
-- 
http://ninedegreesbelow.com
Color management and free/libre photography