[Digikam-users] Re : Choose another ICC profile for converting pictures

[Remco Viëtor]

On Friday 07 October 2011 07:31:05 Martin wrote:
> Am 06.10.2011 21:12, schrieb Paulux:
> > I've a precision to make : as I understand the Digikam way to manage ICC
> > profile, it now (I'm sure it wasn't the case in the past) sorts profiles
> > by type (i.e. the output profiles menu only shows and manages output
> > type profiles, and so on). That's roughly a good idea for the digikam
> > control panel, BUT not for the color space conversion tool in picture
> > editor and batch tool. This one only shows display ICC profiles, but it
> > should offer output ICC profiles in order to completely control the
> > colors behavior before print works, especially with remote laboratories.
> 
> I don't think it is a good idea to convert a photo to the colour space
> of the printing machine. These profiles should be used for soft proofing
> only and this has nothing to do with the workspace colour profile (these
> must not and mostly do not match the display profile).
> 
..
Even worse: screen and printer profiles are NOT colour spaces, but only output 
corrections from a (device-independent) colour space to an imperfect output 
device. They are specific for a combination of a colour space and a device. 

A colour space describes how a colour we can see under standardised lighting 
conditions is encoded in an RGB triplet. This is absolutely device-
independent.

So a colour workspace cannot 'match' a display profile, they are completely 
different beasts and should be used together to get the best output possible.

Yes, I know both colour spaces and device profiles have .icc or .icm 
extensions, but again, they are completely different concepts. 

So, please leave your images in the sRGB colour space, unless you REALLY know 
what you are doing: 
a lot of questions concerning dark, muddy, unsaturated colours in prints come 
from people using e.g. Adobe RGB as editing colour space, and then sending of 
those images to a commercial printer (99+ % of those expect sRGB and don't 
check...) 

Remco