[argyllcms] Re: Printer Profile - Black Gamma Problem

From: Paul Langmead <paul@xxxxxxxxxxxxxxxx>
To: argyllcms@xxxxxxxxxxxxx
Date: Tue, 19 Jun 2018 16:52:10 +0200

Correct, the application of BPC appears to be solely for the purposes of
visualisation.

IIRC, what I read was on the Argyll page in the section where the developer
justifies his continued use of ICC v2 instead of switching to ICC v4.0. I'm
busy with clients this week but I'll see if I can find it again and post a
link here.

Cheers,
Paul

__________________________________________________________
Atelier Paul Langmead
Wilhelminenhofstraße 68a, Berlin 12459
paullangmead.com / +49 (0)17677251462 / paul@xxxxxxxxxxxxxxxx

On Tue, 19 Jun 2018 at 16:33, rbfigueira <rbfigueira@xxxxxxxxx> wrote:

Hi Nikolay,

Thanks for all replies!!

Ok, to summarize ... If is a prerogative of color management software, not
an ICC profile itself ... in the end (*print the image on paper*) there
aren’t any difference if I have the same “profile” with or without the
black point compensation into 0 intent
I am right ?

Thanks

On 19 June 2018 at 15:20, Nikolay Pokhilchenko <
dmarc-noreply@xxxxxxxxxxxxx> wrote:

AFAIK, the BPC procedure is a prerogative of color management software,
not an ICC profile itself. Strictly speaking the profile should not include
black point compensation into 0 intent tables. So the compensation inside
of zero intent is not correct from the standard point of view. IMHO.

Вторник, 19 июня 2018, 17:15 +03:00 от rbfigueira <rbfigueira@xxxxxxxxx>:

Hi Paul,

Ok, but do you know why black point compensation is disabled on Argyll if
is always saved (intent 0) by the commercial software ?
Thanks

On 19 June 2018 at 14:44, Paul Langmead <paul@xxxxxxxxxxxxxxxx
<https://e.mail.ru/compose/?mailto=mailto%3apaul@xxxxxxxxxxxxxxxx>>
wrote:

In the last step of creating a profile you have the option to compare the
profile you just made with others. Once you close the software its gone.
This is one reason I changed to Argyll, its just better software.

Paul
__________________________________________________________
Atelier Paul Langmead
Wilhelminenhofstraße 68a, Berlin 12459
<https://maps.google.com/?q=Wilhelminenhofstra%C3%9Fe+68a,+Berlin+12459&entry=gmail&source=g>
paullangmead.com / +49 (0)17677251462 / paul@xxxxxxxxxxxxxxxx
<https://e.mail.ru/compose/?mailto=mailto%3apaul@xxxxxxxxxxxxxxxx>

On Tue, 19 Jun 2018 at 15:42, rbfigueira <rbfigueira@xxxxxxxxx
<https://e.mail.ru/compose/?mailto=mailto%3arbfigueira@xxxxxxxxx>> wrote:

Hi Paul,

When you compared with the x-rite software ? X-rite has one software to
compare profiles ? Any link ?
Thanks for your reply ;)

On 19 June 2018 at 14:15, Paul Langmead <paul@xxxxxxxxxxxxxxxx
<https://e.mail.ru/compose/?mailto=mailto%3apaul@xxxxxxxxxxxxxxxx>>
wrote:

All my profiles show the same thing when compared in ColorSync utility,
but when compared in the x-rite software both profiles are as similar as I
would expect.

I recall reading somewhere that the visualisation for intent 0 is always
saved by the commercial software with black point compensation enabled,
Argyll doesn't do this - hence the difference.

Cheers,
Paul Langmead

On Tue, 19 Jun 2018 at 3:05 PM, rbfigueira <rbfigueira@xxxxxxxxx
<https://e.mail.ru/compose/?mailto=mailto%3arbfigueira@xxxxxxxxx>> wrote:

Hi Nikolay,

I'm only judging by gamuts comparison but the software not lie. I am
using ColorSync mac utility and what I see is what I will get on print.

- Using the default i1Studio/ColorMunki (100 patches) I get more gamma
details on blacks and less on brighter colors.
- Using argyllcms (420 patches) I get more gamma details on brighter
colors but *completely lose **gamma details on blacks*.

Does the argyllcms have an option to optimize the profile?

I have used this options:

colprof -v -qh -r1.0 -S AdobeRGB.icc -cmt -dpp -D"i1_ArgII_HFA_FABaryta"
i1_ArgII_HFA_FABaryta

On 19 June 2018 at 13:42, Nikolay Pokhilchenko <
dmarc-noreply@xxxxxxxxxxxxx
<https://e.mail.ru/compose/?mailto=mailto%3admarc%2dnoreply@xxxxxxxxxxxxx>

wrote:

Hi. Is your comparison real print based or you're judging only by gamuts
comparison? What rendering intent you're using for test prints or on screen
proofing? Most of preceptual differences are depending on rendering intent
choice and on "black point compensation" use.

Вторник, 19 июня 2018, 13:42 +03:00 от rbfigueira <rbfigueira@xxxxxxxxx
<https://e.mail.ru/compose/?mailto=mailto%3arbfigueira@xxxxxxxxx>>:

Hi Friends,

I have create one printer profile and I get this:
Profile check complete, errors(CIEDE2000): max. = 1.769361, avg. =
0.311779, RMS = 0.371871

So far so good :)

If I compare the ArgyII (420 patches) profile with the default
i1Studio/ColorMunki (100 patches) ... the white is the ArgyII profile...
you will see that I get more gamma brighter colors with the ArgyII profile
but I lose the details (gamma) on shadows - dark colors.

What I have to do to get more (gamma) on shadows - dark colors.
Thanks

Best,
Ricardo

Николай Похильченко

--
Paul Langmead
paullangmead.com
+4917677251462

Николай Похильченко

References:
- [argyllcms] Printer Profile - Black Gamma Problem
  - From: rbfigueira
- [argyllcms] Re: Printer Profile - Black Gamma Problem
  - From: Paul Langmead
- [argyllcms] Re: Printer Profile - Black Gamma Problem
  - From: rbfigueira
- [argyllcms] Re: Printer Profile - Black Gamma Problem
  - From: Nikolay Pokhilchenko
- [argyllcms] Re: Printer Profile - Black Gamma Problem
  - From: rbfigueira

[argyllcms] Re: Printer Profile - Black Gamma Problem

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