lcms-user

[Lcms-user] LCMS soft proofing options and PhotoShop's simulate black ink and paper

[Elle S. <ell...@ni...>]

Can LCMS be used to provide soft proofing options like PhotoShop's 
"simulate black ink" and "simulate paper"?

I seem to remember seeing similar options in Cinepaint, which used LCMS 
version 1. But looking in the Cinepaint code, all I see is this:

menus_set_state ("<Image>/View/Simulatate Paper", gdisp->cms_proof_flags 
==INTENT_ABSOLUTE_COLORIMETRIC);

The Cinepaint code almost looks like absolute colorimetric intent is the 
same as  "simulate paper". But that can't be right, can it? And even if 
that's what the Cinepaint code actually did, is the PhotoShop option 
doing something else?

Best,
Elle

Re: [Lcms-user] LCMS soft proofing options and PhotoShop's simulate black ink and paper

[Florian H. <lis...@ho...>]

Am 18.05.2016 um 21:16 schrieb Elle Stone:
> The Cinepaint code almost looks like absolute colorimetric intent is
> the same as  "simulate paper". But that can't be right, can it?

That should be right.

> And even if that's what the Cinepaint code actually did, is the
> PhotoShop option doing something else?

Not as far as I know.

When "Simulate paper" is checked, PS uses abs. col.
When only "Simulate black ink" is checked, PS uses rel. col.
If neither are checked, PS uses rel. col. with black point compensation.

Cheers,

Florian.

Re: [Lcms-user] LCMS soft proofing options and PhotoShop's simulate black ink and paper

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

Am 18.05.2016 um 21:16 schrieb Elle Stone:
> Can LCMS be used to provide soft proofing options like PhotoShop's 
> "simulate black ink" and "simulate paper"?
> 
> I seem to remember seeing similar options in Cinepaint, which used LCMS 
> version 1. But looking in the Cinepaint code, all I see is this:
> 
> menus_set_state ("<Image>/View/Simulatate Paper", gdisp->cms_proof_flags 
> ==INTENT_ABSOLUTE_COLORIMETRIC);

For the lcms2 API one needs to set the adaption state as well in order
to obtain a monitor to light both match. That way the
oyranos-image-display viewer shows the same result like with lcms1.

kind regards
Kai-Uwe

Re: [Lcms-user] LCMS soft proofing options and PhotoShop's simulate black ink and paper

[Elle S. <ell...@ni...>]

On 05/19/2016 02:03 AM, Kai-Uwe Behrmann wrote:
> Am 18.05.2016 um 21:16 schrieb Elle Stone:
>> Can LCMS be used to provide soft proofing options like PhotoShop's
>> "simulate black ink" and "simulate paper"?
>>
>> I seem to remember seeing similar options in Cinepaint, which used LCMS
>> version 1. But looking in the Cinepaint code, all I see is this:
>>
>> menus_set_state ("<Image>/View/Simulatate Paper", gdisp->cms_proof_flags
>> ==INTENT_ABSOLUTE_COLORIMETRIC);
>

So there wasn't an equivalent Cinepaint option for "simulate black ink"? 
(If there's a way to compile Cinepaint on Gentoo, I haven't found it.)

> For the lcms2 API one needs to set the adaption state as well in order
> to obtain a monitor to light both match. That way the
> oyranos-image-display viewer shows the same result like with lcms1.

Thanks! That is a helpful pointer. Did/does the Cinepaint/Oyranos 
"simulate paper" match the PhotoShop "simulate paper"?

Best,
Elle

Re: [Lcms-user] LCMS soft proofing options and PhotoShop's simulate black ink and paper

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

Am 19.05.2016 um 14:10 schrieb Elle Stone:
> On 05/19/2016 02:03 AM, Kai-Uwe Behrmann wrote:
> So there wasn't an equivalent Cinepaint option for "simulate black ink"?
> (If there's a way to compile Cinepaint on Gentoo, I haven't found it.)

I never thought about that. Oyranos git should be in Gentoo. At least we
obtain patches from Gentoo.

> Did/does the Cinepaint/Oyranos
> "simulate paper" match the PhotoShop "simulate paper"?

Back when implementing that stuff, I checked visually with lots of
prints and light both comparisons and found satisfying results in
CinePaint. However, my goal was not to blindly follow PhotoShop. So no
guarantee for identical output.

kind regards
Kai-Uwe