[Openicc] Fwd: Re: Krita color adjusting

[Jan-Peter Homann]

Casper Boemann schrieb:
> On Tuesday 14 June 2005 11:11, Jan-Peter Homann wrote:
> 
>>Hello Caspar, hello list
>>
>
>>As I explained to you, my goal is to use abstract-profiles or
>>devicelink-profiles as universal exchange format for color-adjustments.
>>In this case, a coloradjustment could be applied to all applications,
>>which use lcms or argyllcms.
> 
> 
> Won't it be a problem that you can't recreate the way the profile was
>  created?

No, it should only be used, if a coloradjustment should be applied 
several times


> 

>>2) Workingspace, Simulationspace, Outputspace
>>----------------------------------------------

>>The profilechain is:
>>workingspace-simulationspace-monitorprofile
>>workingspace-simulationspace-printerprofile
>>workingspace-Save with transformation and embedding the simulation
>>colorspace
> 
> 
> Pretty smart idea that I thought of myself, but it more or less requires that
> we decide on a working space once and for all?
> I thought that XYZ would be a good workingspace, but we have a problem with
> our natural painting then. So in order to stay flexible in accomodating _any_
> colorspace I don't think this is the way to go.


No, you can´t implement this easily with lcms, as it allows such 
profile-chains with free configurable profiles.
So you can e.g use differnt wide gamut RGB workingspaces or Lab/LCH 
workingspace henever you want.
The "proof-function" in Adobe-apps is based on the same scheme.


> 
>>3) Workingspace, adjustmentlayer, outputspace
>>------------------------------------------------

>>So the krita-team has to made following decision:
>>- should there be a Master RGB-workingspace ?
> 
> 
> possibly for the natural painting model, but not in general. I think that
> should be a per colormodel decission.
> 
> 
>>- If yes, how should different workinspaces be evaluated ?

> I don't understand

Different workingspaces influence the natural-paint simulation.
So you should look, which workingspace fits good this goal.

One point you should consider for deviceindependent coloradjustments:
If you are working with colormodels with more then 3-channels (e.g. 
CMYK-profiles), then you loose the information through converting
CMYK-Lab(with coloradjustment)-CMYK
At least some basic "per channel corrections" like curves for every 
channel should implemented devicedependent.

:-)Jan-Peter

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