[Digikam-users] R Digikam - Darktable workflow - Color profile

[Remco Viëtor]

On Tuesday 03 January 2012 14:05:38 Marie-Noëlle Augendre wrote:
> Just to be more precise, a RAW file has nothing to do with colour, in fact.
> It's only luminance information that is captured, then filtered and
> analyzed on three different channels R, G and B. When derawtizing, it's up
> to you to decide what importance you'll give to each channel and 'compose'
> your colour up to your liking.
Just a nit: the light is filtered before it hits the sensor, so before it is 
captured... 
And yes, you decide on developing the raw the relative importance of each 
channel, when you set the white balance. But that correction assumes a certain 
ideal behaviour (as you just scale each channel). Profiling is used to correct 
for response errors in your sensor (deviations from linearity, baseline 
offsets, etc.)

> And you'll do that in the colour space you choose, and you need to transfer
> this information to each output device that will adjust the rendering using
> its own ICC profile.
> 

A camera profile is there to ensure that the transfer to your working colour 
space is as close to correct as possible... 

> Here are very some interesting pages on the subject, but I'm afraid you'll
> need to understand some french to put them to good use:
> http://www.guide-gestion-des-couleurs.com/introduction-gestion-des-couleurs.
> html
> 
> Marie-Noëlle

Well, it all depends on what you need: if all you want is to be sure that what 
you see on screen is as close as possible to what you will get in print, you 
can ignore camera calibration. That's when you can modify the colours to your 
liking

However, if you need exact colours (i.e. what you get in print is what you 
actually could see when taking the picture), you'll need to calibrate your 
camera as well. The response of your sensor/filter screen is not ideal, so 
you'll have to correct for any deviation from the ideal behaviour. This is 
especially important for portraits (skin colours being rather sensitive to 
errors), and could be important for certain scientific applications.

Remco