lcms-user

[Lcms-user] Softproofing with parametric tonecurve

[Tobias E. <me...@ho...>]

Hello,

I am currently struggling to use a profile with a parametric tone curve for 
softproofing. Is there a know limitation regarding that? When I use a straight 
gamma it works. Alternatively I can dump the profile to disk or memory and read 
it again to get something working.

The code to create the profile is here:

https://github.com/darktable-org/darktable/blob/master/src/common/colorspaces.c#L286-L297

and

https://github.com/darktable-org/darktable/blob/master/src/common/colorspaces.c#L238-L284

I would appreciate any hints about what is happening.

Thanks
Tobias

Re: [Lcms-user] Softproofing with parametric tonecurve

[Kai-Uwe B. <ku...@gm...>]

Am 20.06.2016 um 12:19 schrieb Tobias Ellinghaus:
> I am currently struggling to use a profile with a parametric tone 
> curve for softproofing. Is there a know limitation regarding that? 
> When I use a straight gamma it works. Alternatively I can dump the 
> profile to disk or memory and read it again to get something 
> working.

Could you compare with the cmsCreate_sRGBProfile() API?

Re: [Lcms-user] Softproofing with parametric tonecurve

[Tobias E. <me...@ho...>]

On Monday 20 June 2016 21:47:48 Kai-Uwe Behrmann wrote:
> Am 20.06.2016 um 12:19 schrieb Tobias Ellinghaus:
> > I am currently struggling to use a profile with a parametric tone
> > curve for softproofing. Is there a know limitation regarding that?
> > When I use a straight gamma it works. Alternatively I can dump the
> > profile to disk or memory and read it again to get something
> > working.
> 
> Could you compare with the cmsCreate_sRGBProfile() API?

Such a profile doesn't work either. Interestingly I can't even salvage it by 
going through the cmsSaveProfileToMem/cmsOpenProfileFromMem cycle.

Tobias

PS: This is with lcms 2.7 from Debian.