Re: [Gimp-developer] New Image/Color Management option

2016-06-05 Thread Elle Stone

On 06/05/2016 12:12 PM, Øyvind Kolås wrote:

On Sun, Jun 5, 2016 at 3:48 AM, Elle Stone
 wrote:

On 06/04/2016 02:21 PM, Alexandre Prokoudine wrote:


Supposing the option was renamed to be more explicit about what it
does, would it still bother you?


Making color management "disappear" for users who prefer to not ever think
about color management (very different from "disable color management") is
not such a bad goal, though the new image/color management options don't
(imho) accomplish this goal.

Maybe try something along these lines?

Put a user option in Preferences/Color Management that says "Check this box
if you really don't want to ever be bothered with color management." Write
an explanation that says something like:


If you check this box, the following will happen:

1. sRGB will be used as your monitor profile. If your monitor has an sRGB
emulation mode, please enable it.
  (Perhaps add additional options for users who don't want to think about
color management but do have a monitor or installed system profile that they
want GIMP to use).

2. All color management options will be grayed out in the UI.


Such graying out is a good idea; all of this code is unfinished code
that mitch is currently working on, combined with graying out as well
as setting the title of the titleboxes to the name of the internal
sRGB profile - I think a short text of "Assume sRGB for all profile
settings" might be sufficient for such a check--box, if that is the
direction GIMP choses to take on this issue.


The above text for this proposed global setting in "Preferences/Color 
Management" sounds good to me. Maybe add an "on-hover" pop-up that 
explains the purpose of this option is to allow the user to avoid 
dealing with color management?





3. All imported images will automatically be converted to sRGB for editing.
You won't have to think about this. It will just happen.


Perhaps there could be a warning that color information might be discarded?



For some people this might not be what they desired though; they might
have desired assignment of sRGB rather than conversion to sRGB - to
preserve numeric values; thankfully for sRGB images those actions
would have the same result.


It's been my experience that people who don't understand basic color 
management also don't understand the difference between converting to 
and assigning a profile.


Also, the current option in Image/Color Management to Discard the ICC 
profile already does discard the assigned/embedded profile and assign 
sRGB in its place.


"Ppreserving numeric values" might be a bit of an advanced concept for 
the target group of users. What do you think?





4. Your XCF files will be automatically saved in the sRGB color space.

5. All exported images will be exported as untagged sRGB images.
  (Perhaps add an option to embed an sRGB profile from disk for users who
are aware of how Firefox default color management settings. Though this
might be "too much information" as they would also need to know the
difference between what makes sense for UI elements in web design, vs what
makes sense for photographic images.)

Well, it's just a thought. I get emails from people asking me how to avoid
color management as much as possible, and above is pretty much the advice I
give them, and they do seem to understand and follow through. They even
understand the part about Firefox default color management settings once
they've been given an explanation.


The goal of the setting mitch has started experimenting with is a
response to similar desires users baffled by the permutation of
possible misconfigurations of color management continue to express.


In case it wasn't clear, I was proposing the above as an alternative to 
the new "Image/Color Management" and "New Image" options that have been 
added to the menus.


I think the recently added options are very likely to create more (not 
less) confusion in the minds of the target audience of users that find 
color management confusing.


Best,
Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-06-05 Thread Øyvind Kolås
On Sun, Jun 5, 2016 at 3:48 AM, Elle Stone
 wrote:
> On 06/04/2016 02:21 PM, Alexandre Prokoudine wrote:
>>
>> Supposing the option was renamed to be more explicit about what it
>> does, would it still bother you?
>
> Making color management "disappear" for users who prefer to not ever think
> about color management (very different from "disable color management") is
> not such a bad goal, though the new image/color management options don't
> (imho) accomplish this goal.
>
> Maybe try something along these lines?
>
> Put a user option in Preferences/Color Management that says "Check this box
> if you really don't want to ever be bothered with color management." Write
> an explanation that says something like:
>
> >snip<
>
> If you check this box, the following will happen:
>
> 1. sRGB will be used as your monitor profile. If your monitor has an sRGB
> emulation mode, please enable it.
>  (Perhaps add additional options for users who don't want to think about
> color management but do have a monitor or installed system profile that they
> want GIMP to use).
>
> 2. All color management options will be grayed out in the UI.

Such graying out is a good idea; all of this code is unfinished code
that mitch is currently working on, combined with graying out as well
as setting the title of the titleboxes to the name of the internal
sRGB profile - I think a short text of "Assume sRGB for all profile
settings" might be sufficient for such a check--box, if that is the
direction GIMP choses to take on this issue.

> 3. All imported images will automatically be converted to sRGB for editing.
> You won't have to think about this. It will just happen.

For some people this might not be what they desired though; they might
have desired assignment of sRGB rather than conversion to sRGB - to
preserve numeric values; thankfully for sRGB images those actions
would have the same result.

> 4. Your XCF files will be automatically saved in the sRGB color space.
>
> 5. All exported images will be exported as untagged sRGB images.
>  (Perhaps add an option to embed an sRGB profile from disk for users who
> are aware of how Firefox default color management settings. Though this
> might be "too much information" as they would also need to know the
> difference between what makes sense for UI elements in web design, vs what
> makes sense for photographic images.)
>
> Well, it's just a thought. I get emails from people asking me how to avoid
> color management as much as possible, and above is pretty much the advice I
> give them, and they do seem to understand and follow through. They even
> understand the part about Firefox default color management settings once
> they've been given an explanation.

The goal of the setting mitch has started experimenting with is a
response to similar desires users baffled by the permutation of
possible misconfigurations of color management continue to express.

/pippin
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Re: [Gimp-developer] New Image/Color Management option

2016-06-05 Thread Øyvind Kolås
On Sun, Jun 5, 2016 at 5:14 PM, Gez  wrote:
>> There is also flipping to/from formats with alpha. Pre-multiplied and
>> non-premultiplied alpha. As well as flips to/from higher and lower
>> bit-depths as well as to/from CIE Lab. By necessity of the operations
>> involved, working on linear data is another one of these constraints
>> that should be fulfilled. Whenever possible the developer/designer of
>> image processing algorithms should be burdened with reducing the
>> number of parameters, as well as sticking with good defaults - making
>> efficient work-flows possible. If you continue calling it "babl
>> flips"
>> I will start calling your non-flipping-babl a lobotomized babl - you
>> could also collapse "RaGaBaA float" into "RGBA float" along with
>> "R'G'B'A float" to make babl even less capable of providing internal
>> color / pixel-representation management for GEGL and thus GIMP and
>> other applications using GEGL. Before scaling or blurring an image a
>> user would then have to run a pre-multiply filter and after-wards
>> un-premultiply filter.
>
> The fully automatic choice of alpha association is not always the best
> way to go.
> Sure, there are many documented cases where you know exactly what's the
> most adequate association, but then there are also cases (which are not
> corner cases at all) that completely fall apart with an automatic
> selection.
> For instance, take an EXR file with luminescent transparent pixels.
> That's a perfectly valid case that is used extensively in VFX to
> composite fire, light effects and any kind of emissive phenomena that
> produce light but don't occlude light from the background.
> It's important to note that what I mention is not a hack used by
> artists at all. It's a valid alpha compositing situation described both
> in the original porter-duff paper and the EXR specs.
> If you feed that data to a program that decides a strategy of alpha
> association, the most probable outcome is that the information in
> pixels with zero alpha is discarded.
> There is an infamous thread at Adobe Forums that had the most renowned
> imagers ranting about how Photoshop was screwing image data because
> programmers decided for users and made assumptions.
>
> That's why it's important to know what artists will do with your
> software before making such assumptions.
> I'm not saying that every single option in a graphics program should
> come with a toggle, but you can't choose for users if you don't know
> what they need.

babl being able to deal with pre-multipled/associated and
non-premultiplied / non-associated alpha/transparency and know if a
buffer contains one or the other is a neccesary for being able to make
the choice of doing things automatically or not in GEGL/GIMP ; remove
this capabilitity from babl - like removing the capability to request
RGB data in a linear variant of the used RGB color space, removes the
ability to deal with thing automatically and requires full manual
control by the operator.

/pippin - digital media artist and toolsmith
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Re: [Gimp-developer] New Image/Color Management option

2016-06-05 Thread Øyvind Kolås
On Sun, Jun 5, 2016 at 5:14 PM, Gez  wrote:
> El dom, 05-06-2016 a las 09:26 +0200, Øyvind Kolås escribió:
>>
>> > Practical, applied color management is not that complicated.
>> > Neither is
>> > understanding the basics of radiometrically correct editing.
>>
>> Most people - including people doing photography and graphic design
>> work for a living - prefer not to. I used to teach people becoming
>> such professionals at a university level. It should also be possible
>> to use GIMP for color scientists and color science geeks that care
>> more about color accuracy control than image composition.
>
> That should come endorsed by a professional photographer or designer
> saying she doesn't care about color management.
> We can assume that the silence is because nobody cares. But there is
> also a fat chance that there aren't many of those professionals around
> here.
>
> It's also possible that many future professionals at university level
> truly don't care, because they weren't taught about the importance and
> influence of color management in their work.
> I know that was the case with me. The quality of my work improved
> substantially after I understood the basics of color management.
> "just works" for most of the people means "I don't have to care about
> that" and that's a huge mistake.
>
> I do graphic design work for a living, and for ideological reasons I
> chose to do it with free software. I do care about proper color
> management because I know how doing it wrong degrades and limits the
> quality of my work.
>

I am not saying that there should be no ability to do color management
- or that it is worthless. I have been doing color science research as
well as been teaching bits of color reproduction knowledge. I am
saying that expecting a user to understand color management before
being able to do decent work with GIMP and its user interface is
unreasonable. Just like a good photographer beats a bad one with an
expensive camera; detailed knowledge of color management and pixel
representation is secondary to other skills in producing quality
photos.

mitch manages ignore the mailinglist and stay productive - astonishing
given the level of distraction here on gimps mailinglist.

/pippin
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Re: [Gimp-developer] New Image/Color Management option

2016-06-05 Thread Gez
El dom, 05-06-2016 a las 09:26 +0200, Øyvind Kolås escribió:
> 
> > Practical, applied color management is not that complicated.
> > Neither is
> > understanding the basics of radiometrically correct editing.
> 
> Most people - including people doing photography and graphic design
> work for a living - prefer not to. I used to teach people becoming
> such professionals at a university level. It should also be possible
> to use GIMP for color scientists and color science geeks that care
> more about color accuracy control than image composition.

That should come endorsed by a professional photographer or designer
saying she doesn't care about color management.
We can assume that the silence is because nobody cares. But there is
also a fat chance that there aren't many of those professionals around
here.

It's also possible that many future professionals at university level
truly don't care, because they weren't taught about the importance and
influence of color management in their work.
I know that was the case with me. The quality of my work improved
substantially after I understood the basics of color management.
"just works" for most of the people means "I don't have to care about
that" and that's a huge mistake.

I do graphic design work for a living, and for ideological reasons I
chose to do it with free software. I do care about proper color
management because I know how doing it wrong degrades and limits the
quality of my work.


> > I know exactly when I want to use linear RGB and exactly when I
> > want to use
> > perceptually uniform RGB, as do other high end/professional users.
> 
> Maybe not, professional photographers might not know that they want
> pre-multiplied alpha, linear light data for doing resampling, nor
> what
> goes wrong if the pixel data for some reason isn't pre-multiplied or
> linearized, providing constraints that makes such misconfiguration
> hard is a service to novice and professional user alike.

snip


> There is also flipping to/from formats with alpha. Pre-multiplied and
> non-premultiplied alpha. As well as flips to/from higher and lower
> bit-depths as well as to/from CIE Lab. By necessity of the operations
> involved, working on linear data is another one of these constraints
> that should be fulfilled. Whenever possible the developer/designer of
> image processing algorithms should be burdened with reducing the
> number of parameters, as well as sticking with good defaults - making
> efficient work-flows possible. If you continue calling it "babl
> flips"
> I will start calling your non-flipping-babl a lobotomized babl - you
> could also collapse "RaGaBaA float" into "RGBA float" along with
> "R'G'B'A float" to make babl even less capable of providing internal
> color / pixel-representation management for GEGL and thus GIMP and
> other applications using GEGL. Before scaling or blurring an image a
> user would then have to run a pre-multiply filter and after-wards
> un-premultiply filter.

The fully automatic choice of alpha association is not always the best
way to go.
Sure, there are many documented cases where you know exactly what's the
most adequate association, but then there are also cases (which are not
corner cases at all) that completely fall apart with an automatic
selection.
For instance, take an EXR file with luminescent transparent pixels.
That's a perfectly valid case that is used extensively in VFX to
composite fire, light effects and any kind of emissive phenomena that
produce light but don't occlude light from the background.
It's important to note that what I mention is not a hack used by
artists at all. It's a valid alpha compositing situation described both
in the original porter-duff paper and the EXR specs.
If you feed that data to a program that decides a strategy of alpha
association, the most probable outcome is that the information in
pixels with zero alpha is discarded.
There is an infamous thread at Adobe Forums that had the most renowned
imagers ranting about how Photoshop was screwing image data because
programmers decided for users and made assumptions.

That's why it's important to know what artists will do with your
software before making such assumptions.
I'm not saying that every single option in a graphics program should
come with a toggle, but you can't choose for users if you don't know
what they need.


G.

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Re: [Gimp-developer] New Image/Color Management option

2016-06-05 Thread Øyvind Kolås
On Sun, Jun 5, 2016 at 1:16 AM, Elle Stone
 wrote:
>>> If GIMP is being developed for high end workflows as specified in the
>>> Vision
>>> statement, then it's important to get input from people who actually use
>>> high end workflows. Gez is exactly such a person. I think I qualify,
>>> though
>>> I'm not a professional.
>>
>> High-end workflows doesn't have to mean that the user understands all
>> details about things like color-management,
>
> Practical, applied color management is not that complicated. Neither is
> understanding the basics of radiometrically correct editing.

Most people - including people doing photography and graphic design
work for a living - prefer not to. I used to teach people becoming
such professionals at a university level. It should also be possible
to use GIMP for color scientists and color science geeks that care
more about color accuracy control than image composition.

> A professional high end workflow by definition implies that the user
> understands the nature of the provided tools, what the tools can do and what
> the limitations are.

Or the tools provide professional level outputs; tools for digital
media manipulation are abstractions - and a professional should be
able to use tools without knowing how to reimplement the tools.

>> some things can be handled
>> automatically - note that this is not about making it impossible to do
>> things; but harder to do the wrong thing.
>
>
> As an experiment, I tried using default babl/GEGL/GIMP patched to use
> Rec.2020 Y and XYZ, but with the babl flips intact and using an ICC profile
> with the Rec20202 primaries and the sRGB TRC.
>
> I had no way to know, short of looking in the code, which operations were
> being done on linearized RGB, and which on perceptually uniform RGB.
>
> Well, sometimes it was obvious. For example GIMP by default uses
> perceptually uniform RGB for Curves and Levels, and this is radiometrically
> incorrect and produces all kinds of obvious gamma artifacts.

These are bugs.

> I know exactly when I want to use linear RGB and exactly when I want to use
> perceptually uniform RGB, as do other high end/professional users.

Maybe not, professional photographers might not know that they want
pre-multiplied alpha, linear light data for doing resampling, nor what
goes wrong if the pixel data for some reason isn't pre-multiplied or
linearized, providing constraints that makes such misconfiguration
hard is a service to novice and professional user alike.

> The babl flips take that critically important freedom of choice away from
> me.


>>> I've had a small number of high end users including two bonified
>>> professionals from very different fields look at both default GIMP and my
>>> patched GIMP which has the babl flips disabled. Unanimously these people
>>> say
>>> that there is no way they would use default GIMP because the babl flips
>>> interfere with their workflow. Plus they need the option to work in wider
>>> color spaces than sRGB. But they liked using my patched GIMP.
>>
>>
>>> snip<
>>
>>
>>> Let's be completely clear about this: These high end users and
>>> professionals
>>> aren't praising  *my* coding ability or *my* vision for GIMP. I'm a
>>> terrible
>>> coder and all I've done in my patched GIMP is disable the babl flips, add
>>> a
>>> few extra LCH functionalities, and recently added "anyrgb".
>>
>>
>> One of the important features of the "babl flips" is that they make
>> gamma erros as they apply to scaling and blurring, and more go away
>> see http://www.4p8.com/eric.brasseur/gamma.html GEGL code in general
>> prefers using linear variants of the used RGB color-space for
>> processing (and compositing).
>
>
> One of the professionals who has used my patched GIMP (actually there were
> three professional that I know of, I don't usually ask people who send me
> emails what they do for a living, but sometimes they tell me anyway) has
> specifically noted that for scaling an image to a larger size, scaling
> perceptually uniform RGB can provide a smoother result. And the babl flips
> take this option away from users of default GIMP.
>
> This points to a shortcoming in the "make all the decisions for the user"
> approach to coding: It assumes the devs know better than the users what is
> the right thing to do.

We make decisions for the user, in what capabilities are included, and
where menu items are. To return to the topic of this thread; the
decision to make it easy to "assume all settings as sRGB" temporarily,
and then flip back to the custom perhaps misconfigured settings is
another such service realising that not all operators of the software
know or care as deeply about ICC workflows as you do.

>> One major short-coming of babl/GEGL
>> color handling currently - as elle has pointed out, is for operations
>> that multiply pixels values - like the multiply layer mode - most
>> editing features in GIMP do not rely on multiplication of color
>> 

Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 02:21 PM, Alexandre Prokoudine wrote:

Supposing the option was renamed to be more explicit about what it
does, would it still bother you?


Making color management "disappear" for users who prefer to not ever 
think about color management (very different from "disable color 
management") is not such a bad goal, though the new image/color 
management options don't (imho) accomplish this goal.


Maybe try something along these lines?

Put a user option in Preferences/Color Management that says "Check this 
box if you really don't want to ever be bothered with color management." 
Write an explanation that says something like:


If you check this box, the following will happen:

1. sRGB will be used as your monitor profile. If your monitor has an 
sRGB emulation mode, please enable it.
 (Perhaps add additional options for users who don't want to think 
about color management but do have a monitor or installed system profile 
that they want GIMP to use).


2. All color management options will be grayed out in the UI.

3. All imported images will automatically be converted to sRGB for 
editing. You won't have to think about this. It will just happen.


4. Your XCF files will be automatically saved in the sRGB color space.

5. All exported images will be exported as untagged sRGB images.
 (Perhaps add an option to embed an sRGB profile from disk for 
users who are aware of how Firefox default color management settings. 
Though this might be "too much information" as they would also need to 
know the difference between what makes sense for UI elements in web 
design, vs what makes sense for photographic images.)


Well, it's just a thought. I get emails from people asking me how to 
avoid color management as much as possible, and above is pretty much the 
advice I give them, and they do seem to understand and follow through. 
They even understand the part about Firefox default color management 
settings once they've been given an explanation.


Best,
Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 12:12 PM, Alexandre Prokoudine wrote:


Probably 90% of commits are done by a single person who is already
overworked. What re-evaluation are you talking about? Is this
discussion for real?


You mean Mitch. Mitch is the heart and soul of GIMP. Without Mitch, 
where would GIMP be?


Mitch has written a *lot* of new color management code over the last 
several years, and it's excellent. I watch for new color management code 
as it's committed to git, and I try really hard to pick holes in the 
code from the point of view of "does it work", and Mitch's code works.


I don't know how many of you realize the color picking tools are now 
color-managed and the code works perfectly, except for an issue with 
colors that the user might like to pick that are outside the sRGB color 
gamut.


I certainly couldn't have written that code. In fact I tried to several 
times over the last year and made no progress at all.


I can't help but notice how much of the GIMP color management code deals 
with the switches between linearized RGB (linearized from the sRGB TRC) 
and perceptually uniform RGB (meaning the sRGB TRC).


Writing color management code would surely be easier if the babl 
flip-related code were stripped out of babl/GEGL/GIMP. I rather suspect 
a lot of the rest of the code also would be simpler to write.


Best,
Elle


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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 05:37 PM, Øyvind Kolås wrote:

On Sat, Jun 4, 2016 at 11:13 PM, Elle Stone
 wrote:

If GIMP is being developed for high end workflows as specified in the Vision
statement, then it's important to get input from people who actually use
high end workflows. Gez is exactly such a person. I think I qualify, though
I'm not a professional.


High-end workflows doesn't have to mean that the user understands all
details about things like color-management,


Practical, applied color management is not that complicated. Neither is 
understanding the basics of radiometrically correct editing.


A professional high end workflow by definition implies that the user 
understands the nature of the provided tools, what the tools can do and 
what the limitations are.



some things can be handled
automatically - note that this is not about making it impossible to do
things; but harder to do the wrong thing.


As an experiment, I tried using default babl/GEGL/GIMP patched to use 
Rec.2020 Y and XYZ, but with the babl flips intact and using an ICC 
profile with the Rec20202 primaries and the sRGB TRC.


I had no way to know, short of looking in the code, which operations 
were being done on linearized RGB, and which on perceptually uniform RGB.


Well, sometimes it was obvious. For example GIMP by default uses 
perceptually uniform RGB for Curves and Levels, and this is 
radiometrically incorrect and produces all kinds of obvious gamma artifacts.


I know exactly when I want to use linear RGB and exactly when I want to 
use perceptually uniform RGB, as do other high end/professional users.


The babl flips take that critically important freedom of choice away 
from me.



I've had a small number of high end users including two bonified
professionals from very different fields look at both default GIMP and my
patched GIMP which has the babl flips disabled. Unanimously these people say
that there is no way they would use default GIMP because the babl flips
interfere with their workflow. Plus they need the option to work in wider
color spaces than sRGB. But they liked using my patched GIMP.



snip<



Let's be completely clear about this: These high end users and professionals
aren't praising  *my* coding ability or *my* vision for GIMP. I'm a terrible
coder and all I've done in my patched GIMP is disable the babl flips, add a
few extra LCH functionalities, and recently added "anyrgb".


One of the important features of the "babl flips" is that they make
gamma erros as they apply to scaling and blurring, and more go away
see http://www.4p8.com/eric.brasseur/gamma.html GEGL code in general
prefers using linear variants of the used RGB color-space for
processing (and compositing).


One of the professionals who has used my patched GIMP (actually there 
were three professional that I know of, I don't usually ask people who 
send me emails what they do for a living, but sometimes they tell me 
anyway) has specifically noted that for scaling an image to a larger 
size, scaling perceptually uniform RGB can provide a smoother result. 
And the babl flips take this option away from users of default GIMP.


This points to a shortcoming in the "make all the decisions for the 
user" approach to coding: It assumes the devs know better than the users 
what is the right thing to do.



One major short-coming of babl/GEGL
color handling currently - as elle has pointed out, is for operations
that multiply pixels values - like the multiply layer mode - most
editing features in GIMP do not rely on multiplication of color
components.


Well, actually many editing operations in GIMP are 
chromaticity-dependent, producing different results in different RGB 
working spaces, precisely because multiply itself is chromaticity-dependent.


For a list see Section B of this article:
http://ninedegreesbelow.com/photography/unbounded-srgb-as-universal-working-space.html#chromaticities-matter.

For editing examples, see Section C of the same article.

For a more technical discussion, see these three articles:

Multiplying out of gamut colors in the unbounded sRGB color space 
produces meaningless results 
(http://ninedegreesbelow.com/photography/unbounded-srgb-multiply-produces-meaningless-results.html)


Color correction fails in unbounded sRGB 
(http://ninedegreesbelow.com/photography/unbounded-srgb-color-correction-fails.html)


About RGB Colourspace Models Performance 
(http://colour-science.org/posts/about-rgb-colourspace-models-performance/)


And this thread: https://www.freelists.org/post/argyllcms/White-Point,45


At the moment things are a mix of constraints of 8bit like GIMP-2.8
had and how closely workflows from 2.8 are reproducible in the
development version, some features and menu options in GIMP-2.9 are
not desirable as a finished streamlined GEGL based editing experience.


This is exactly what Gez was saying: there are constraints on GIMP 2.10 
for legacy/backward-compatibility reasons.



After 

Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Øyvind Kolås
On Sat, Jun 4, 2016 at 11:13 PM, Elle Stone
 wrote:
> If GIMP is being developed for high end workflows as specified in the Vision
> statement, then it's important to get input from people who actually use
> high end workflows. Gez is exactly such a person. I think I qualify, though
> I'm not a professional.

High-end workflows doesn't have to mean that the user understands all
details about things like color-management, some things can be handled
automatically - note that this is not about making it impossible to do
things; but harder to do the wrong thing.

> I've had a small number of high end users including two bonified
> professionals from very different fields look at both default GIMP and my
> patched GIMP which has the babl flips disabled. Unanimously these people say
> that there is no way they would use default GIMP because the babl flips
> interfere with their workflow. Plus they need the option to work in wider
> color spaces than sRGB. But they liked using my patched GIMP.

>snip<

> Let's be completely clear about this: These high end users and professionals
> aren't praising  *my* coding ability or *my* vision for GIMP. I'm a terrible
> coder and all I've done in my patched GIMP is disable the babl flips, add a
> few extra LCH functionalities, and recently added "anyrgb".

One of the important features of the "babl flips" is that they make
gamma erros as they apply to scaling and blurring, and more go away
see http://www.4p8.com/eric.brasseur/gamma.html GEGL code in general
prefers using linear variants of the used RGB color-space for
processing (and compositing). One major short-coming of babl/GEGL
color handling currently - as elle has pointed out, is for operations
that multiply pixels values - like the multiply layer mode - most
editing features in GIMP do not rely on multiplication of color
components.

At the moment things are a mix of constraints of 8bit like GIMP-2.8
had and how closely workflows from 2.8 are reproducible in the
development version, some features and menu options in GIMP-2.9 are
not desirable as a finished streamlined GEGL based editing experience.
After GIMP-2.10 and GIMP-3.0 get released; I hope we can see a
significant trimming down of the UI for instance the precision menu in
GIMP, defaulting to 32bit floating point with linear TRC (maybe with
precision over-ridable per layer - to save memory) in addition to
other improvements that might break more GIMP-2.8 era assumptions and
constraints. This is also when experimenting with filters embedded in
the layer stack similar to adjustment layers/effect layers and more is
on the roadmap.

Elles simplified babl/GEGL with removed the TRC to/from linear
conversions or as she calls it "babl flips" will make GIMP produce
wrong results for scaling, blurring and more - *unless* the user has
specifically chosen to edit in a linear RGB space; only then will
scaling or blurring and other resampling produce correct results.
Another issue not dealt with by Elles approach to patching babl/GEGL
is juggling multiple immutable different RGB formats in one process.
GIMP can open multiple images with different ICC profiles - and we
want users to be able to predictably view and copy/paste between
multiple images with different profiles. How this is dealt with isn't
certain - some ideas have gone into a babl roadmap, but the needs are
summed up in this email.

I see it as important to get a working 2.10 released, what we
currently have in git is better than GIMP-2.8 in most ways. More
important than to perfect it so that we start the work on making a
GIMP using GTK3 in master - as well as adding more advanced
non-destructive features based on GEGL after 3.0. With GIMP 2.10 and
3.0 maybe there will be an influx of interest from developers or
sponsorship and I have the motivation to properly add such
capabilities to babl myself - for now I am the janitor/maintainer of
GEGL - making sure also not to break expectations other software have
from it - enjoy some goats https://www.youtube.com/watch?v=GJJPgLGrSgc

/pippin
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Boudewijn Rempt

On Sat, 4 Jun 2016, Elle Stone wrote:


On 06/04/2016 05:28 PM, Boudewijn Rempt wrote:

To be honest... We get a lot of feedback like "Where can I disable color
management, it's too complicated, I don't want this, why should I want
this,
Paintool Sai doesn't have it, it makes my images weird in firefox, you guys
suck".


Tell them to choose sRGB as the monitor profile and the image profile. 
Problem solved. In GIMP they can use the built-in sRGB profile as the monitor 
profile by choosing "None".




That's what we do -- it just doesn't work! People can get incredibly angry
at learning that they have some learning to do.

--
Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 05:36 PM, Elle Stone wrote:

Tell them to choose sRGB as the monitor profile and the image profile.
Problem solved.


Oh, and set their monitor to sRGB emulation mode, if it's available.

Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Boudewijn Rempt

On Sat, 4 Jun 2016, Elle Stone wrote:

Keep in mind that many "don't know/don't want to know" users do manage to use 
high end software like PhotoShop, Krita, and Blender without the software 
being hampered by training wheels, belts and suspenders.


To be honest... We get a lot of feedback like "Where can I disable color
management, it's too complicated, I don't want this, why should I want this,
Paintool Sai doesn't have it, it makes my images weird in firefox, you guys
suck".

--
Boudewijn Rempt | http://www.krita.org, http://www.valdyas.org
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 12:12 PM, Alexandre Prokoudine wrote:


What re-evaluation are you talking about? Is this
discussion for real?


I think there does need to be a real and on-going discussion.

If GIMP is being developed for high end workflows as specified in the 
Vision statement, then it's important to get input from people who 
actually use high end workflows. Gez is exactly such a person. I think I 
qualify, though I'm not a professional.


I've had a small number of high end users including two bonified 
professionals from very different fields look at both default GIMP and 
my patched GIMP which has the babl flips disabled. Unanimously these 
people say that there is no way they would use default GIMP because the 
babl flips interfere with their workflow. Plus they need the option to 
work in wider color spaces than sRGB. But they liked using my patched GIMP.


One comment was that my patched GIMP, and especially with the extra LCH 
functionality, felt natural to use and was an easy replacement for 
PhotoShop. A related comment was that the LCH functionalities open up 
new possibilities for digital painting.


One comment was that if my patched GIMP had one additional feature 
that's already on the GIMP roadmap - something to do with 
non-destructive ediing but I don't remember the specifics - it would be 
the preferred editing application for many high end users. Other people 
also mentioned non-destructive editing and of course adjustment layers 
and the ability to easily record and replay repetitive actions.


A comment made by a couple of people was that the unbounded floating 
point ICC profile editing was incredibly useful, something apparently 
PhotoShop and most other image editors don't support very well.


Let's be completely clear about this: These high end users and 
professionals aren't praising  *my* coding ability or *my* vision for 
GIMP. I'm a terrible coder and all I've done in my patched GIMP is 
disable the babl flips, add a few extra LCH functionalities, and 
recently added "anyrgb".


These people are talking about the truly awesomely excellent work that 
*everyone* on the GIMP team has done, with Mitch doing most of the 
actual coding for GIMP. So they were complimenting all of you devs, or 
all of us devs (people keep telling me I'm one of the GIMP devs).


And speaking of vision, I never would have realized the usefulness of 
unbounded image editing, which I think is from Pippin's vision. But now 
I can't imagine going back to editing bounded RGB.


As Gez has suggested, I think the GIMP devs should start seeking out 
high end users and asking for specific concrete feedback, which is 
something I've been trying to do for the last year.


Keep in mind that many "don't know/don't want to know" users do manage 
to use high end software like PhotoShop, Krita, and Blender without the 
software being hampered by training wheels, belts and suspenders.


Best,
Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Jason van Gumster

Gez  wrote:

> ...GIMP doesn't provide the tools for editing such maps...

Maybe I'm simply not understanding. Typically these kinds of maps get edited
with color curves, layer blending modes (straight-forward mathematical ones
like multiply, add, and subtract are most intuitive), and painting. How does
GIMP not provide these tools?

I'm sure I'm missing something obvious here. If you could explain what you
mean, I'd be most appreciative.

Thanks.

  -Jason
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Jason van Gumster

Elle Stone  wrote:

> On 05/20/2016 02:37 PM, Jason van Gumster wrote:
> >
> > Elle Stone  wrote:
> >  
> >> I can't think of a single use case for trying to edit a non-color-manged
> >> image in an ICC profile color-managed editing application such as GIMP.  
> >
> > I think I can think of one: creating displacement/bump maps (often used as
> > textures in 3D graphics). Often in that case, pixel values aren't treated as
> > color, but a numeric non-color data (i.e. it's an instruction to displace
> > geometry---or other pixels---by this numeric mapping value).
> >
> > But perhaps the artists that create these maps are not covered in the
> > audience specified in GIMP's vision statement.
> >  
> In point of fact, the new GIMP color management options do NOT disable 
> ICC profile color management.
> 
> If you want to disable color management, go into "Edit/Preferences/Color 
> Management" and for "Image display mode" select "No color management".
> 
> Or you can achieve the same effect by assigning your monitor profile to 
> the image file.
>
And that's all well and good, but either my ignorance is showing or this is
starting to sound like a case of semantics. I wasn't asking for the process of
how one might go about editing a non-color-managed image in a color-managed
application like GIMP. I was simply pointing out that there *is* at least one
use case for doing so.

As for the mechanics of actually doing this, you've pointed out a couple ways
to go about it (though disabling color management for the entire application
feels excessive). When working on these kinds of images---er, *maps*---aside
from numeric accuracy of the actual values, the priority when editing is being
able to see as much of the full range as possible, with even proportion between
values. To that end, temporarily assigning the monitor's color space to the map
is probably the best approach, I think.

That said, this does get me thinking and wondering a bit (though still
tangentially on-topic). A few GIMP filters such as Depth Merge, Lighting
Effects, Bump Map, and Displace rely on these kinds of maps. So technically,
you could have a color managed image that includes one or more of these maps on
separate layers. Ideally, it would be nice to be able to reliably edit those
layers as non-color maps without splitting them into different images with
their own independent "non"-color space.

How would you propose that GIMP handle color management in that case? In
Blender's compositor, for example, there's an option to explicitly set an input
image node to be interpreted as non-color data. Would it make sense to offer
that kind of option to individual layers in GIMP? If that doesn't make sense,
what's an alternative approach that *does*?

Thanks.

  Jason
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 02:21 PM, Alexandre Prokoudine wrote:

On Sat, Jun 4, 2016 at 9:04 PM, Elle Stone wrote:

On 06/04/2016 01:50 PM, Alexandre Prokoudine wrote:


Including softproofing?



Of course not.


Given the tensions, we are not in a situation where "of course I meant
something entirely different" is a sensible approach to a
conversation.


OK, fair enough.




2. "File/New/Color manage this image".
Unchecking this option does NOT disable color management, but merely
assigns the GIMP built in sRGB profile to the image, which is already the
default color profile for new images.


Supposing the option was renamed to be more explicit about what it
does, would it still bother you?


The only wording that doesn't mislead the user is something like:

"Uncheck this option to assign the GIMP built-in sRGB profile to your 
image".


Which brings us back to the fact that the user already has the option to 
assign the GIMP built-in sRGB profile, using "Image/Color 
Management/Assign".


And then there is "Image/Color Management/Discard Color Profile", which 
also assigns the GIMP built-in sRGB profile.


How many ways of assigning the GIMP built-in sRGB profile need to be 
packed into the "Image/Color Management" menu?


How are all these various ways a user now has to assign the GIMP 
built-in sRGB profile going to make things easier for users to understand?





Is this rather sidewise-seeming question a ploy to draw attention away from
more important issues that Gez is trying to draw attention to?


Thank you for testing my patience with annoying, misplaced questions.
It's precisely what I need on a fine Saturday night.


My apologies, I was out of line.

Best,
Elle


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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Alexandre Prokoudine
On Sat, Jun 4, 2016 at 8:11 PM, Elle Stone wrote:

>> If you have a clear vision, how color management should work in GIMP,
>> please share it.
>
>
> 1. Get rid of the babl flip code and attendant linear vs "gamma" precision
> code. Rip it completely out of babl, GEGL, and GIMP. I wrote a patch for
> this back in 2014, and I'd be happy to write a new patch for today's code
> base.
>
> 2. Apply my patches for allowing to edit in any well-behaved user-chosen RGB
> working space.
>
> A start on the above two items is available from my github clones of
> babl/GEGL/GIMP: https://github.com/ellelstone

I vaguely recall design issues with your former proposals, but I for
one would welcome a technical review for your patchset.

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Alexandre Prokoudine
On Sat, Jun 4, 2016 at 9:04 PM, Elle Stone wrote:
> On 06/04/2016 01:50 PM, Alexandre Prokoudine wrote:
>>
>> Including softproofing?
>
>
> Of course not.

Given the tensions, we are not in a situation where "of course I meant
something entirely different" is a sensible approach to a
conversation.

> 2. "File/New/Color manage this image".
>Unchecking this option does NOT disable color management, but merely
> assigns the GIMP built in sRGB profile to the image, which is already the
> default color profile for new images.

Supposing the option was renamed to be more explicit about what it
does, would it still bother you?

> Is this rather sidewise-seeming question a ploy to draw attention away from
> more important issues that Gez is trying to draw attention to?

Thank you for testing my patience with annoying, misplaced questions.
It's precisely what I need on a fine Saturday night.

> Namely the
> fact that GIMP is morphing into an image editor that won't serve the needs
> of the target audience outlined in the GIMP vision statement?

Have faith, Elle.

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 01:50 PM, Alexandre Prokoudine wrote:

Gez hasn't posted any false information.

He has.

What false information? Can you be specific? I don't see any false 
information.


Elle
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 01:50 PM, Alexandre Prokoudine wrote:

Including softproofing?


Of course not.

Gez wasn't talking about the new soft proofing options, and neither am 
I. Gez was talking about the same options that have always been the 
subject of this particular thread, which is to say:


1. "Image/Color Management/Enable Color management".
   Unchecking this option does NOT disable color management but merely 
assigns the GIMP built in sRGB profile.
   This task can already be accomplished by going to "Image/Color 
Management/Assign Color Profile" and assigning the GIMP built-in sRGB 
profile.


2. "File/New/Color manage this image".
   Unchecking this option does NOT disable color management, but merely 
assigns the GIMP built in sRGB profile to the image, which is already 
the default color profile for new images.


Is this rather sidewise-seeming question a ploy to draw attention away 
from more important issues that Gez is trying to draw attention to? 
Namely the fact that GIMP is morphing into an image editor that won't 
serve the needs of the target audience outlined in the GIMP vision 
statement?


Best,
Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Alexandre Prokoudine
On Sat, Jun 4, 2016 at 8:11 PM, Elle Stone wrote:

>> And you are asking me what knowingly false information you posted? How
>> about this bit above?
>
>
> Gez hasn't posted any false information.

He has.

> His choice of comparing attention
> to themes with attention to the big picture regarding the direction GIMP has
> taken with respect to the needs of people using high end workflows was a bit
> unfortunate (the new themes are very nice and also the result of a lot of
> work from people who don't normally write code for GIMP). But I 100%
> understand and share his frustration.

I get that.

> The new menu items shouldn't do or say anything. They should be removed.

Including softproofing?

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 12:12 PM, Alexandre Prokoudine wrote:

On Sat, Jun 4, 2016 at 6:52 PM, Gez  wrote:

El sáb, 04-06-2016 a las 18:26 +0300, Alexandre Prokoudine escribió:



Why is it the goal of GIMP 2.10 to produce a GEGL-based version
with
feature parity with the current stable?


Where did you even read this?


Oh, come on! You say you never heard that?


I can dig out specific posts if you really want me to. But Gez is quite 
correct - the notion of "backwards compatibility" has from time to time 
received considerable mention on the gimp developers list.




And you are asking me what knowingly false information you posted? How
about this bit above?


Gez hasn't posted any false information. His choice of comparing 
attention to themes with attention to the big picture regarding the 
direction GIMP has taken with respect to the needs of people using high 
end workflows was a bit unfortunate (the new themes are very nice and 
also the result of a lot of work from people who don't normally write 
code for GIMP). But I 100% understand and share his frustration.




Sorry, but the way things are going, I don't see this conversation
leading to anything positive.

If you have a clear vision, how color management should work in GIMP,
please share it.


1. Get rid of the babl flip code and attendant linear vs "gamma" 
precision code. Rip it completely out of babl, GEGL, and GIMP. I wrote a 
patch for this back in 2014, and I'd be happy to write a new patch for 
today's code base.


2. Apply my patches for allowing to edit in any well-behaved user-chosen 
RGB working space.


A start on the above two items is available from my github clones of 
babl/GEGL/GIMP: https://github.com/ellelstone



If you are concerned about new menu options and you think that should
do different things, please tell us exactly what they should do or
say.


The new menu items shouldn't do or say anything. They should be removed. 
If a GIMP user doesn't want to deal with color management, they already 
have the option to only edit sRGB images.


Best,
Elle
--
http://ninedegreesbelow.com
Color management and free/libre photography


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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Elle Stone

On 06/04/2016 11:53 AM, Alexandre Prokoudine wrote:

On Sat, Jun 4, 2016 at 6:17 PM, Gez wrote:


That's what Elle has been fighting against for a long time, and that's
still the problem.


Fighting? Against? This is a community project. We don't fight here,
we make stuff happen. Althought it looks like you really, really want
to fight.

"Support for RGB working spaces other than sRGB" is already in the
roadmap, which one might attribute to Elle's eloquence.


Just to set the record straight regarding the outcome of my "eloquence":

Beginning in April 2014, and with help from several other people, I 
spent an enormous amount of time and effort testing and documenting the 
inadequacies of the babl architecture that uses unbounded sRGB as a 
universal working space and pseudo-PCS: 
http://gimp.1065349.n5.nabble.com/template/NamlServlet.jtp?macro=search_page=2=unbounded+sRGB=0


The net result of my long campaign to persuade the babl/GEGL/GIMP devs 
to abandon their long-planned sRGB-only architecture is:


1. A few paragraphs in the babl roadmap: 
https://git.gnome.org/browse/babl/tree/docs/roadmap.txt


2. A promise that "eventually" GIMP will support editing in color spaces 
other than sRGB: http://wiki.gimp.org/wiki/Roadmap


This is a pitifully small return for the amount of effort I and others 
have put into trying to turn GIMP around so it can become the amazing 
image editor that it would already be if the misguided babl architecture 
had been abandoned back in 2014, as it should have been.


For the foreseeable future:

* GIMP 2.9/2.10 is in fact an "unbounded sRGB only image editor": 
http://ninedegreesbelow.com/photography/unbounded-srgb-as-universal-working-space.html


* GIMP code is still written around the misguided notion of "sRGB as 
PCS": 
http://gimp.1065349.n5.nabble.com/Don-t-make-an-architectural-mistake-based-on-a-groundless-premise-td43812.html#a43875


I feel partly responsible for the current sad state of GIMP code because 
in the long discussion of the babl architecture the question came up 
concerning whether the babl flips should also be abandoned. I said they 
could be useful. I didn't realize just how invasively they would spread 
through the GIMP code base.


In retrospect, the sensible thing to do is to completely remove all 
traces of the babl flips from babl/GEGL/GIMP. If this is done, then when 
a person wants to edit a linear gamma image, all they have to do is 
convert the image to a linear gamma ICC RGB working space. The babl 
flips aren't needed for linear gamma image editing.


And then institue "per layer/layer group" ability to flip to a 
user-specified TRC for the very few cases where an informed imager 
really does want or need to edit nonlinear RGB.


Uninformed GIMP users would still have the option to edit in the regular 
sRGB color space as they already do.


Best,
Elle
--
http://ninedegreesbelow.com
Color management and free/libre photography

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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Alexandre Prokoudine
On Sat, Jun 4, 2016 at 6:52 PM, Gez  wrote:
> El sáb, 04-06-2016 a las 18:26 +0300, Alexandre Prokoudine escribió:
>>
>> Personally, I'm fine with a rant that has helpful bits of information
>> in it that could be extracted. All I can extract from your rant is
>> that you are annoyed so much that you post knowingly false
>> information.
>
> What "knowingly flase information"?
>
>> How does it help us make GIMP better?
>
> Hopefully making people involved take one step back and re-evaluate how
> they are addressing the target audience's needs.

Probably 90% of commits are done by a single person who is already
overworked. What re-evaluation are you talking about? Is this
discussion for real?

>> > Why is it the goal of GIMP 2.10 to produce a GEGL-based version
>> > with
>> > feature parity with the current stable?
>>
>> Where did you even read this?
>
> Oh, come on! You say you never heard that?

And you are asking me what knowingly false information you posted? How
about this bit above?

Sorry, but the way things are going, I don't see this conversation
leading to anything positive.

If you have a clear vision, how color management should work in GIMP,
please share it.

If you are concerned about new menu options and you think that should
do different things, please tell us exactly what they should do or
say.

If you are concerned about core CM features, tell us what they should
or should not do, exactly.

But if you expect to be listened to and taken seriously, don't start
the conversation with this sort of a rant.

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Gez
El sáb, 04-06-2016 a las 18:26 +0300, Alexandre Prokoudine escribió:
> 
> Personally, I'm fine with a rant that has helpful bits of information
> in it that could be extracted. All I can extract from your rant is
> that you are annoyed so much that you post knowingly false
> information. 

What "knowingly flase information"?

> How does it help us make GIMP better?

Hopefully making people involved take one step back and re-evaluate how
they are addressing the target audience's needs.


> > Why is it the goal of GIMP 2.10 to produce a GEGL-based version
> > with
> > feature parity with the current stable?
> 
> Where did you even read this?

Oh, come on! You say you never heard that?
That the linear mode was a side effect from switching to GEGL, that
some features like that weren't supposed to be in 2.10 as the minimum
goal was producing a GEGL version of the 2.8 features, and anything
else would be a plus?
Iirc it was in the context of the first discussion about color
management (supporting other colorspaces than just sRGB). And iirc it
sounded as a pretext for kicking it to the future roadmap.
I don't have a link to a ml thread or an IRC log, so you'll have to
take my word.

G.


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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Alexandre Prokoudine
On Sat, Jun 4, 2016 at 6:24 PM, Gez wrote:

> Do you think that my e-mail didn't provide any useful insights?

It had zero technical information, only a rant. Why don't _you_ re-read it?

>> People who work on themes and icons are not the same people who work
>> on e.g. color management. C'mon, Gez, you've been around for long
>> enough to know that.
>
> Sure, but that's not the point.

No, it _is_ the point. There a ca. 1K people subscribed to this list,
and very few of them are actual contributors. I suspect most of them
are just genuinely interested in what's going on and provide their
input when they feel it's necessary. Sure, you can judge the whole
community by that, but how sensible of an idea that would be is
anyone's guess.

> I'm not charging against the guys who
> made the themes. I'm questioning that the development community seems
> to pay more attention to those secondary things rather than focusing on
> the real shit.

Like I said, you well aware of the fact that most discussions take place on IRC.

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Gez
El vie, 20-05-2016 a las 14:37 -0400, Jason van Gumster escribió:
> Elle Stone  wrote:
> 
> > I can't think of a single use case for trying to edit a non-color-
> > manged 
> > image in an ICC profile color-managed editing application such as
> > GIMP.
> 
> I think I can think of one: creating displacement/bump maps (often
> used as
> textures in 3D graphics). Often in that case, pixel values aren't
> treated as
> color, but a numeric non-color data (i.e. it's an instruction to
> displace
> geometry---or other pixels---by this numeric mapping value).
> 
> But perhaps the artists that create these maps are not covered in the
> audience
> specified in GIMP's vision statement.
> 
>   -Jason

If pixel values aren't supposed to be treated as color, then they
shouldn't go through any color operation.
I mean, no operation should turn your RGB data to XYZ, LCH or whatever.
In GIMP, GEGL operations decide when that happens, so your pixels are
likely to be treated like color anyway and the no-color management
option in this case wouldn't make any difference.

As Alex mentioned, the artists who create those maps are not
necessarily excluded from the target audience, but GIMP doesn't provide
the tools for editing such maps, and it will always treat them as sRGB
(which means that CM on or off won't make any difference).

Gez.


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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Alexandre Prokoudine
On Sat, Jun 4, 2016 at 6:00 PM, Gez wrote:

> Of course not, but take a quick look at the GIMP mailing lists archives
> and see how much attention got that minor subject and how much
> attention other important subjects receive.
>
> That speaks volumes about the priorities of the project.

That speaks nothing about priorities. Most discussions on development
take place on IRC, and those discussions are about all sorts of dev
efforts. Which you are well aware of, because you are on that channel
and you participate in those discussions. I have logs proving that.

So why don't you take one step back and re-evaluate your claims?

Personally, I'm fine with a rant that has helpful bits of information
in it that could be extracted. All I can extract from your rant is
that you are annoyed so much that you post knowingly false
information. How does it help us make GIMP better?

> Why is it the goal of GIMP 2.10 to produce a GEGL-based version with
> feature parity with the current stable?

Where did you even read this?

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Gez
El sáb, 04-06-2016 a las 14:22 +0300, Alexandre Prokoudine escribió:
> On Sat, Jun 4, 2016 at 5:25 AM, Gez wrote:
> 
> > I'm one of the few guys around using GIMP professionally in the
> > field
> > of graphic design, and with each decision like this one, pointing
> > to
> > the wrong audience (not the audience defined in the "product
> > vision")
> > I'm becoming less and less convinced that it is a good idea to keep
> > using it.
> 
> Would you like to talk about the issue in hand rather than go around
> bashing developers without providing useful insights?

Do you think that my e-mail didn't provide any useful insights?
Read again. I think that, despite the apparent angry tone, it says a
couple of things about taking care of your audience and making
decisions for them, not for the wrong people.

We can tal about that anytime.


> People who work on themes and icons are not the same people who work
> on e.g. color management. C'mon, Gez, you've been around for long
> enough to know that.

Sure, but that's not the point. I'm not charging against the guys who
made the themes. I'm questioning that the development community seems
to pay more attention to those secondary things rather than focusing on
the real shit.

G.
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Gez
El sáb, 04-06-2016 a las 11:04 +0200, Simon Budig escribió:
> I don't understand your line of reasoning. Did you realize, that
> Mitch
> has literally spent months to make color management actually work in
> Gimp - i.e. cut'n'paste between images with different color profiles
> attached, color managed color selectors etc. pp.
> 
> And now all this work is jeopardized, because he made a preferences
> option to disable this stuff a little bit more visible? And we seem
> to
> have troubles in finding a correct way to describe what this toggle
> button does?
> 
> If this is your line of reasoning, then, sir, your priorities are
> messed up.

I couldn't care less about what the toogle does.
It's secondary. The problem here is the motivation for including such
toggle.
No serious imager would think about turning CM off. Introducing that
toggle is producing a feature that is not needed by the supposed
audience of the tool.

And it's not only that. What resulted from this discussion is even more
concerning. Like this claim for instance:

"And then we have this "even without a profile, pixels have some
meaning. And in GIMP, the default meaning is sRGB."

That's absolutely wrong. Without a colorspace definition, pixels ARE
meaningless.
RGB is just 3 colored lights. The value of an RGB pixel is only light
intensity (from no intensity to max) and has no information whatsoever
about the color of each primary.

In GIMP the default meaning is sRGB because it was decided that RGB
means sRGB. So when CM is off you're not treating those pixels as
pixels, you're treating them as sRGB.
Because of GEGL, GIMP expect them to be sRGB. So CM converts them to
sRGB anyway, no CM treats them as sRGB anyway.

That's what Elle has been fighting against for a long time, and that's
still the problem.

The CM or no-CM discussion only uncovers this issue once again.
GIMP 2.9 is still a sRGB editor, assuming sRGB everywhere.
Again, GIMP provides something that is enough for the wrong audience,
but clearly inadequate and insufficient for the supposedly intended
audience.

G.

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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Gez
El sáb, 04-06-2016 a las 10:07 +0200, Michael Schumacher escribió:
> 
> On 06/04/2016 04:25 AM, Gez wrote:
> 
> > The most pressing issues (like performance and quality) are
> > constantly
> > postponed. But hey, we have a new dark theme and new icons.
> 
> We have these because there are people interested in them and
> contributing to GIMP.
> 
> I'm not going to tell them to stop doing this. You?

Of course not, but take a quick look at the GIMP mailing lists archives
and see how much attention got that minor subject and how much
attention other important subjects receive.

That speaks volumes about the priorities of the project.
Why is it the goal of GIMP 2.10 to produce a GEGL-based version with
feature parity with the current stable?
Why is legacy support so important? where are the users saying that
their work will suffer if you move from sRGB compositing to linear
compositing?

So no, I'm not going to tell anybody to stop doing what they are doing.
I'm not the one who has to set your priorities, it's you. 

Is it your priority to produce a great image manipulation software?
Then give imagers the tools they need.

Gez.
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Alexandre Prokoudine
On Sat, Jun 4, 2016 at 5:25 AM, Gez wrote:

> I'm one of the few guys around using GIMP professionally in the field
> of graphic design, and with each decision like this one, pointing to
> the wrong audience (not the audience defined in the "product vision")
> I'm becoming less and less convinced that it is a good idea to keep
> using it.

Would you like to talk about the issue in hand rather than go around
bashing developers without providing useful insights?

> The most pressing issues (like performance and quality) are constantly
> postponed. But hey, we have a new dark theme and new icons.
>
> This is ridiculous.

People who work on themes and icons are not the same people who work
on e.g. color management. C'mon, Gez, you've been around for long
enough to know that.

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Simon Budig
Hi Gez.

Gez (lis...@ohweb.com.ar) wrote:
> Although I share your shock, I think Michael is right. Almost nobody
> using GIMP understands color management, because there is virtually
> nobody using GIMP seriously, and probably nobody will because of this
> kind of design decisions.
[...]
> Instead of focusing on imagers devs seem to be focusing on eventual
> users who only use the tool once a month for scaling some photos and
> remove red eyes or making banners for online forums.

I don't understand your line of reasoning. Did you realize, that Mitch
has literally spent months to make color management actually work in
Gimp - i.e. cut'n'paste between images with different color profiles
attached, color managed color selectors etc. pp.

And now all this work is jeopardized, because he made a preferences
option to disable this stuff a little bit more visible? And we seem to
have troubles in finding a correct way to describe what this toggle
button does?

If this is your line of reasoning, then, sir, your priorities are messed
up.

Bye,
Simon

-- 
  si...@budig.de  http://simon.budig.de/
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Re: [Gimp-developer] New Image/Color Management option

2016-06-04 Thread Michael Schumacher


On 06/04/2016 04:25 AM, Gez wrote:

> The most pressing issues (like performance and quality) are constantly
> postponed. But hey, we have a new dark theme and new icons.

We have these because there are people interested in them and
contributing to GIMP.

I'm not going to tell them to stop doing this. You?

-- 
Regards,
Michael
GPG: 96A8 B38A 728A 577D 724D 60E5 F855 53EC B36D 4CDD
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Re: [Gimp-developer] New Image/Color Management option

2016-06-03 Thread Gez
El vie, 13-05-2016 a las 00:15 +0200, Simone Karin Lehmann escribió:
> > 
> > The prefs option is for display color management, and will soon
> > only be a default for a per-display switch.
> > 
> > The option in Image -> New allows to disable color management
> > and whatever color management transforms on a per-image base.
> > 
> 
> Woooh, I can’t believe it! You’re saying that
> 
> > This is mainly because almost nobody understands what this
> > whole color stuff is about at all.
> 
> Is this how you think about all the people who use GIMP? That almost
> none of them understands color management? 

Although I share your shock, I think Michael is right. Almost nobody
using GIMP understands color management, because there is virtually
nobody using GIMP seriously, and probably nobody will because of this
kind of design decisions.

I'm one of the few guys around using GIMP professionally in the field
of graphic design, and with each decision like this one, pointing to
the wrong audience (not the audience defined in the "product vision")
I'm becoming less and less convinced that it is a good idea to keep
using it.

The most pressing issues (like performance and quality) are constantly
postponed. But hey, we have a new dark theme and new icons.

This is ridiculous. And this is what is keeping serious users from
being interested in the application.
And if things keep going in this direction, GIMP will end up losing the
handful of people actually using it seriously and caring about it.

Instead of focusing on imagers devs seem to be focusing on eventual
users who only use the tool once a month for scaling some photos and
remove red eyes or making banners for online forums.

If that's the audience you care about, please amend the product vision
so people like me can move on, since there is no future for us with
GIMP. Eventual users and clueless people can learn. It only takes
education.
Aiming low with features like this only makes us, the real audience,
want to run in the opposite direction.


Gez.



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Re: [Gimp-developer] New Image/Color Management option

2016-05-20 Thread Elle Stone

On 05/20/2016 02:45 PM, Alexandre Prokoudine wrote:

On Fri, May 20, 2016 at 9:37 PM, Jason van Gumster wrote:


But perhaps the artists that create these maps are not covered in the audience
specified in GIMP's vision statement.


They are.

Alex


And the needs of artists who create these maps are NOT better met by the 
new bogus and highly misleading color management options.


The new options to uncheck color managing an image do NOT disable color 
management.


Best,
Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-05-20 Thread Elle Stone

On 05/20/2016 02:37 PM, Jason van Gumster wrote:


Elle Stone  wrote:


I can't think of a single use case for trying to edit a non-color-manged
image in an ICC profile color-managed editing application such as GIMP.


I think I can think of one: creating displacement/bump maps (often used as
textures in 3D graphics). Often in that case, pixel values aren't treated as
color, but a numeric non-color data (i.e. it's an instruction to displace
geometry---or other pixels---by this numeric mapping value).

But perhaps the artists that create these maps are not covered in the audience
specified in GIMP's vision statement.

In point of fact, the new GIMP color management options do NOT disable 
ICC profile color management.


If you want to disable color management, go into "Edit/Preferences/Color 
Management" and for "Image display mode" select "No color management".


Or you can achieve the same effect by assigning your monitor profile to 
the image file.


However, for your particular use case, you don't really care what the 
image looks like. And with color management disabled what it looks like 
depends on your monitor's display characteristics.


So you might as well leave color management enabled and use the GIMP 
built-in sRGB profile as the image profile.


You can assign the GIMP built-in sRGB profile using "Image/Color 
Management/Assign".


You don't need the new and HIGHLY MISLEADING "Image/Color Management" 
options to assign the GIMP built-in sRGB profile.


Best,
Elle
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Re: [Gimp-developer] New Image/Color Management option

2016-05-20 Thread Alexandre Prokoudine
On Fri, May 20, 2016 at 9:37 PM, Jason van Gumster wrote:

> But perhaps the artists that create these maps are not covered in the audience
> specified in GIMP's vision statement.

They are.

Alex
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Re: [Gimp-developer] New Image/Color Management option

2016-05-20 Thread Jason van Gumster

Elle Stone  wrote:

> I can't think of a single use case for trying to edit a non-color-manged 
> image in an ICC profile color-managed editing application such as GIMP.

I think I can think of one: creating displacement/bump maps (often used as
textures in 3D graphics). Often in that case, pixel values aren't treated as
color, but a numeric non-color data (i.e. it's an instruction to displace
geometry---or other pixels---by this numeric mapping value).

But perhaps the artists that create these maps are not covered in the audience
specified in GIMP's vision statement.

  -Jason

/me scurries off to a corner
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Re: [Gimp-developer] New Image/Color Management option

2016-05-18 Thread Elle Stone

On 05/16/2016 11:43 AM, Michael Natterer wrote:

On Mon, 2016-05-16 at 17:26 +0200, Michael Natterer wrote:



2. Relabel the option as "Assume this image is an sRGB image".

That definitely not, but I will immediately add tooltips saying that
it is the same as choosing sRGB.


Done, this should be more obvious now:

commit c0fb1362034fb4da24ee46a677f9833495ee6ca5
Author: Michael Natterer 
Date:   Mon May 16 17:41:04 2016 +0200

 app: add tooltips that mention that disabling color management ==
sRGB

 Also say "better leave this enabled".

commit 335727dd267a44ac48fc4fdfa1678f7005fbb50f
Author: Michael Natterer 
Date:   Mon May 16 17:37:22 2016 +0200

 libgimpwidgets: change the tooltip of GimpColorConfig:mode

 to say "How images are displayed on screen." instead of "Mode of
 operation for color management.". The old text was never accurate.



I beg to differ. The old text was perfectly descriptive. The new text is 
merely vague.


Before there was ICC profile color management, when a person displayed 
an image on their monitor, what they saw depended entirely on their 
monitor, that is, on the type of phosphors (assuming a CRT) used to make 
colors, combined with the  state of calibration of their monitor.


In other words, before ICC profile color management, everyone edited 
their images in their monitor's color space.


Limiting ourselves to the most basic, practical, applied level of color 
management - ICC profile color management of RGB images displayed on a 
monitor screen requires three things:


1. That the monitor be assigned an ICC display profile that describes 
the monitor's display characteristics.


2. That the image be assigned an ICC RGB working space profile that 
properly interprets (give meaning to) the image RGB values.


3. That a CMM such as LCMS be used to convert the image from the image's 
assigned ICC RGB working space profile to the monitor's assigned ICC 
display profile.


By definition, disabling ICC profile color management means the above 
three-listed items don't happen. Instead the image RGB values are sent 
directly to the screen.


The new GIMP "color management" options are *LYING* to the user.

When making a new image, unchecking "Color manage this image" does *NOT* 
disable color management.


When navigating to "Image/Color Management", unchecking "Enable color 
management" does *NOT* disable color management.


Please find another set of "UI" words for designating these new options.

Or better yet get rid of the new options as they are guaranteed to cause 
a great deal of confusion and misunderstanding among GIMP users.


Best,
Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-05-16 Thread Michael Natterer
On Mon, 2016-05-16 at 17:26 +0200, Michael Natterer wrote:
> 
> > 2. Relabel the option as "Assume this image is an sRGB image".
> That definitely not, but I will immediately add tooltips saying that
> it is the same as choosing sRGB.

Done, this should be more obvious now:

commit c0fb1362034fb4da24ee46a677f9833495ee6ca5
Author: Michael Natterer 
Date:   Mon May 16 17:41:04 2016 +0200

app: add tooltips that mention that disabling color management ==
sRGB

Also say "better leave this enabled".

commit 335727dd267a44ac48fc4fdfa1678f7005fbb50f
Author: Michael Natterer 
Date:   Mon May 16 17:37:22 2016 +0200

libgimpwidgets: change the tooltip of GimpColorConfig:mode

to say "How images are displayed on screen." instead of "Mode of
operation for color management.". The old text was never accurate.
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Re: [Gimp-developer] New Image/Color Management option

2016-05-16 Thread Michael Natterer
On Sun, 2016-05-15 at 09:28 -0400, Elle Stone wrote:
> On 05/15/2016 08:14 AM, Elle Stone wrote:
> > 
> > 2. Relabel the option as "Assume this image is an sRGB image".
> And make this option be *un*checked by default, of course. So the
> image 
> by default is color-managed in the normal way. And checking the new 
> option would make GIMP treat the image "as if" it were an sRGB
> image, 
> even if it's not.
> 
> Sorry about leaving this part out.

Yea, reversing the meaning of the label would of course
reverse the meaning of the default.

But aside from what I wrote before, I think that "disable"
toggles are a bad thing in general.

"Enable this option to disable something" -> what? -> bad.

--Mitch

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Re: [Gimp-developer] New Image/Color Management option

2016-05-16 Thread Michael Natterer
On Sun, 2016-05-15 at 08:14 -0400, Elle Stone wrote:
> On 05/12/2016 03:56 PM, Michael Natterer wrote:
> > 
> > On Thu, 2016-05-12 at 08:46 -0400, Elle Stone wrote:
> > > 
> > > > 
> > > > There is a new "Image/Color Management" option to "Enable Color
> > > > Management". The option is checked by default. For sRGB images,
> > > > checking
> > > > or unchecking the option doesn't seem to make any difference.
> > Exactly, even without a profile, pixels have some meaning. And
> > in GIMP, the "default" meaning is sRGB.
> Frankly I don't see the utility of this new option. Users who don't
> want 
> to deal with the complexities of ICC profile color management
> already 
> have the option to only edit sRGB images.

True, but they need to know that what they want is equivalent
to using sRGB. They want a "don't bother me with any of this"
setting because they really don't know or don't want to know
any of it.

> But if there really is a defensible use case, here are two concrete 
> suggestions:
> 
> 1. Move this new option down to the group of options below and
> separated 
> from the two normal Color Management options.

Do you mean in the new submenu? IMO a global "enable" switch
clearly belongs at the beginning of a section.

> 2. Relabel the option as "Assume this image is an sRGB image".

That's exactly what is confusing to them :) "What is sRGB again?"

> Here is why I'm making these two suggestions:
> 
> GIMP menu items and help hover tips shouldn't misinform GIMP users,
> but 
> instead should tell GIMP users the truth and also help to educate
> them.

I agree, and propose to have tooltips that disabling is the same
as using the built-in sRGB profiles.

> In an ICC profile color-managed editing application, pixels are 
> literally meaningless without knowing which ICC profile should be
> used 
> to give the channel values meaning. You can't change the very basis
> of 
> ICC profile color management by arbitrarily deciding that for GIMP
> "no 
> profile" actually means "sRGB". Because it doesn't. And pretending
> that 
> it does will mislead GIMP users.

But it does, it really does in the code. no profile == sRGB.

> The global switch in "Preferences/Color Management" to set the Image 
> display mode to "No color management" actually does disable color 
> management. This means that the image RGB channel values are sent 
> directly to the screen. This is the functional equivalent of
> assigning 
> the user's chosen monitor profile to all open images.

That switch is *only* for display color management, If you
disable it, things are still properly converted if you
copy pixels between images.

> Unchecking the pre-checked box in the "Images/Color Management" menu 
> that says "Enable Color Management" sounds like it should do the
> exact 
> same thing as going into Preferences and setting the Image display
> mode 
> to "No color management". But what unchecking "Images/Color
> Management" 
> actually does is *assume* the image is an sRGB image, even if the
> image 
> already has an ICC profile that's not the sRGB profile. This
> assumption 
> only produces the same result as choosing "No color management" in 
> Preferences if the user has also chosen sRGB as their monitor profile
> in 
> "Preferences/Color Management".

I just reorganized the prefs page and it should now be clearer that it 
is meant for display settings only.

> The truthful and less confusing verbiage for this prechecked 
> "Images/Color Management/Enable Color Management" option would be 
> "Images/Color Management/Assume this image is an sRGB image".

We can have a tooltip saying so, but using that suggested wording
defeats the "don't bother me, I don't want to understand it"
purpose of the setting.

> Also, the position of the new option gives it "mouse scrolling" and 
> "visual" importance. The user has to read and then scroll past this
> new 
> option to get to the more normal Color Management options to assign
> or 
> convert to a new ICC profile.

So the new option is at the right place. Sorry, but I'm 100%
convinced that the vast majority of users has no clue whatsoever
about color management. Heck they can't even distinguish pixels
from DPI. A simple was to turn it off is IMO exectly what's needed.

> This prominent placement of the new option in the "Image/Color 
> Management" menu makes it seem like a normal thing to do while
> editing 
> an image is to disable Color Management, which of course isn't at
> all 
> what this option really does.

It switches to default things and that's all it can do, there
are no pixels without meaning ever since we made color management
omnipresent in GIMP.

> So again, if this new option really does have some utility (and again
> I 
> can't see that it does), then it would be better to do the following:
> 
> 1. Move this new option down to the group of options below and
> separated 
> from the two normal Color Management options.

Sorry, nope, unless you convince me with some better arguments :)

Re: [Gimp-developer] New Image/Color Management option

2016-05-16 Thread Elle Stone

On 05/12/2016 10:31 PM, Alexandre Prokoudine wrote:

You are pretty much saying that it is wrong to force freedom of choice upon
people. This doesn't make any sense.


Well certainly the current "Image/Color Management" options do offer 
users a lot of choices. But the same choices already were there in more 
sensible form with less potential for confusing and misleading the user.


Currently these are the choices in "Image/Color Management":

A. The user can leave the new "Enable Color Management" checked as it is 
by default.


B. The user can uncheck "Enable Color Management".

C. The user can assign a new profile, which includes the option to 
assign the built-in GIMP sRGB profile.


D. The user can convert the image to a new profile, which includes the 
option to convert the image to the GIMP sRGB profile.


E. The user can discard the image's profile, unless the image already is 
assigned the GIMP built-in sRGB profile, in which case this option is 
grayed out.


(The last option, to save the color profile to disk, literally saves the 
image's assigned profile to disk as an ICC profile, so isn't related to 
the above-listed options).


Option B seems to provide the user with the option to disable color 
management. But this is not what happens. The image is still color 
managed. It's still converted from the GIMP built-in sRGB profile to the 
user's chosen monitor profile. But if you set GIMP up to display the 
image ICC profile in the status bar, you'll see the words "not color 
managed". In other words, the status bar is lying to the user.


This "new freedom" provided by unchecking "Enable Color Management" 
seems to only be the freedom to internally assign the GIMP sRGB profile 
and at the same time be presented with misinformation about whether the 
image is actually still color managed.


But the user already has the freedom to assign the sRGB profile to an 
image by exercising Option C, which allows the user to assign a new 
profile, which already includes the option to assign the built-in GIMP 
sRGB profile even if it's the wrong profile for the image


And for non-sRGB images the user already has the freedom to assign the 
GIMP built-in sRGB profile by exercising Option E, which really ought to 
be relabelled as "Discard the currently assigned ICC profile and assign 
the GIMP built-in sRGB profile instead".


So can someone please explain to me what the utility of Options B and E, 
that isn't already covered by Option C



Now let's see what really happens when the user exercises her freedom of 
choice and selects one of the "new freedoms" when she's opened a 
non-sRGB image.


For the sake of simplicity, let's assume the following:

1. The image is at "Perceptual gamma precision (sRGB) precision rather 
than "Linear light" precision.


2. The user has selected "Color managed display" in Preferences/Color 
Management.


3. The user chose a real monitor profile in Preferences, instead of 
choosing an sRGB ICC profile as the monitor profile. Let's also assume 
the user has chosen in Preferences to display the image's ICC profile on 
the image status bar.


4. The image is in the ArgyllCMS ClayRGB1998.icm (Adobe-compatible) 
color space. Let's also say this hypothetical image has some nice greens 
and blues that fall outside the very small sRGB color space gamut:


Before exercising her new freedom of choice, the status bar reads 
"Interchangeable with Adobe RGB (1998)" and the image is color-managed 
as usual, which is to say that the image is converted from the image's 
ICC profile (ClayRGB1998.icm) to the user's monitor profile as selected 
in Preferences.


If she now chooses option B and unchecks the option to "Enable Color 
Management", here's what happens:


1. The image appearance does in fact change. The image colors are now 
washed out because what unchecking "Enable Color Management" really does 
is *assign* the GIMP built-in sRGB profile to the image.


2. The status bar says "not color managed". But in fact the image really 
still is color managed because the image is still being converted from 
the assigned image profile to the monitor profile for display. The 
problem is that now the wrong ICC profile has been assigned. So the 
status bar is lying to the user, as can be ascertained by changing the 
Preferences/Color Management "Image display mode" to "No color management".


If the user really wants the freedom to assign the wrong ICC profile to 
an image, well, Option B isn't required as she already has this freedom 
from Option C, which allows the user to assign a new ICC profile, 
including the GIMP built-in sRGB profile, even if this is the wrong 
profile for the image.


Option E is just as bad as Option B. Option E says that it allows the 
user to discard the image's ICC profile, and if the image has any ICC 
profile other than the GIMP built-in sRGB profile, this option is 
available.


So if the user exercises her freedom to discard the image's ICC profile 
for the 

Re: [Gimp-developer] New Image/Color Management option

2016-05-15 Thread Elle Stone

On 05/12/2016 03:56 PM, Michael Natterer wrote:

The option in Image -> New allows to disable color management
and whatever color management transforms on a per-image base.


What specifically is included in "color management transforms"?


This is mainly because almost nobody understands what this
whole color stuff is about at all.


There is a difference between a deep theoretical understanding and a 
working understanding.


Here is everything a user needs for a basic working understanding of 
color management:


1. Make or find an accurate monitor profile. Select that profile in 
Preferences.
 In a worst-case scenario, set the monitor to the 
manufacturer-supplied sRGB preset and use sRGB as the monitor profile.


2. Open an image. If there's no embedded ICC profile, assign the right 
profile. For many (but not all) untagged images, sRGB is the right choice.


3. Convert the image to the user's chosen RGB working space.
 Sadly, in GIMP the RGB working space must be sRGB, or else too 
many editing operations won't work because of the hard-coded sRGB 
parameters in the code base.


4. When you are done editing, convert the image to the desired output 
color space, which for the web should be sRGB.


All (sic!) graphics artists

I know and have asked switch off color management entirely
in Photoshop because it's this confusing thing that changes
colors in an unpredictable way  (which is not surprising
given the cluelessness).


Well, see, PhotoShop doesn't actually provide an option to disable color 
management.


Under "Color Management Policies" there are several options, one of 
which is "Off". But choosing "Off" doesn't do what you might think it 
does. Instead, quoting from an Adobe forum post 
(https://forums.adobe.com/thread/1934844):


""Off" is an illusion, it's not really off. What happens is that the 
working space is assigned to the file no matter what color space the 
file was created in . . . And to top it off, the file is then saved 
without an icc profile, throwing everything completely to the wind even 
if it wasn't before."


I left out part of the quote because it was addressing an issue with a 
broken monitor profile, so see the forum post for the full quote.


What is said in the forum post coheres with what I remember to be the 
case for CS2.


So your confused PhotoShop users are just making a bad situation worse.

There used to be an option in PhotoShop to disable color management for 
*printing*. This option was very useful in advanced printing workflows. 
This option was removed to the great dismay of people trying to make and 
use custom print profiles with PhotoShop. But this is not what you are 
talking about.


There also has been much gnashing of teeth over the years among 
PhotoShop users trying to make CMYK files for printing. But this 
particular color management issue has nothing to do with GIMP, because 
GIMP doesn't support CMYK.



The sane choice way to let users disable it, rather than
forcing it upon them.


If you want to let users disable color management on a per image basis, 
then the per image option should do exactly what the global option in 
"Preferences/Color Management/Image display mode/No color management" 
does, which is "Send the RGB values directly to the screen without doing 
any conversion from the image profile to the monitor profile for display".


I can't think of a single use case for trying to edit a non-color-manged 
image in an ICC profile color-managed editing application such as GIMP.


Best,
Elle

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Re: [Gimp-developer] New Image/Color Management option

2016-05-15 Thread Elle Stone

On 05/15/2016 08:14 AM, Elle Stone wrote:

2. Relabel the option as "Assume this image is an sRGB image".


And make this option be *un*checked by default, of course. So the image 
by default is color-managed in the normal way. And checking the new 
option would make GIMP treat the image "as if" it were an sRGB image, 
even if it's not.


Sorry about leaving this part out.

Elle


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Re: [Gimp-developer] New Image/Color Management option

2016-05-15 Thread Elle Stone

On 05/12/2016 03:56 PM, Michael Natterer wrote:

On Thu, 2016-05-12 at 08:46 -0400, Elle Stone wrote:

>There is a new "Image/Color Management" option to "Enable Color
>Management". The option is checked by default. For sRGB images,
>checking
>or unchecking the option doesn't seem to make any difference.

Exactly, even without a profile, pixels have some meaning. And
in GIMP, the "default" meaning is sRGB.


Frankly I don't see the utility of this new option. Users who don't want 
to deal with the complexities of ICC profile color management already 
have the option to only edit sRGB images.


But if there really is a defensible use case, here are two concrete 
suggestions:


1. Move this new option down to the group of options below and separated 
from the two normal Color Management options.


2. Relabel the option as "Assume this image is an sRGB image".

Here is why I'm making these two suggestions:

GIMP menu items and help hover tips shouldn't misinform GIMP users, but 
instead should tell GIMP users the truth and also help to educate them.


In an ICC profile color-managed editing application, pixels are 
literally meaningless without knowing which ICC profile should be used 
to give the channel values meaning. You can't change the very basis of 
ICC profile color management by arbitrarily deciding that for GIMP "no 
profile" actually means "sRGB". Because it doesn't. And pretending that 
it does will mislead GIMP users.


The global switch in "Preferences/Color Management" to set the Image 
display mode to "No color management" actually does disable color 
management. This means that the image RGB channel values are sent 
directly to the screen. This is the functional equivalent of assigning 
the user's chosen monitor profile to all open images.


Unchecking the pre-checked box in the "Images/Color Management" menu 
that says "Enable Color Management" sounds like it should do the exact 
same thing as going into Preferences and setting the Image display mode 
to "No color management". But what unchecking "Images/Color Management" 
actually does is *assume* the image is an sRGB image, even if the image 
already has an ICC profile that's not the sRGB profile. This assumption 
only produces the same result as choosing "No color management" in 
Preferences if the user has also chosen sRGB as their monitor profile in 
"Preferences/Color Management".


The truthful and less confusing verbiage for this prechecked 
"Images/Color Management/Enable Color Management" option would be 
"Images/Color Management/Assume this image is an sRGB image".


Also, the position of the new option gives it "mouse scrolling" and 
"visual" importance. The user has to read and then scroll past this new 
option to get to the more normal Color Management options to assign or 
convert to a new ICC profile.


This prominent placement of the new option in the "Image/Color 
Management" menu makes it seem like a normal thing to do while editing 
an image is to disable Color Management, which of course isn't at all 
what this option really does.


So again, if this new option really does have some utility (and again I 
can't see that it does), then it would be better to do the following:


1. Move this new option down to the group of options below and separated 
from the two normal Color Management options.


2. Relabel the option as "Assume this image is an sRGB image".

Best,
Elle
--
http://ninedegreesbelow.com
Color management and free/libre photography
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Re: [Gimp-developer] New Image/Color Management option

2016-05-12 Thread Alexandre Prokoudine
13 мая 2016 г. 1:22 пользователь "Simone Karin Lehmann" 
написал:

> Is this how you think about all the people who use GIMP? That almost none
of them understands color management?

There are probably a few dozens of people in the world who really do
understand CM. It's one of those things where the more you know, the more
you don't know.

> May I remind you of your product vision? ->
http://gui.gimp.org/index.php/GIMP_UI_Redesign#product_vision
>
> "GIMP is a platform for programming cutting-edge image processing
algorithms, by scientists and artists"
>
> Do you really think, that these targeted audience, your targerted
audience, doesn’t know what color management is all a bout?

That's the reality.

> So, this is how you think about your target users? They are clueless?
Your target users - professional artists and photographers - switch off
color management, because it’s confusing them?

People who are professionals still do crazy things like tagging a photo
with an ICC profile of a display. And yes, I know quite a handful of those
who found CM to be too complicated, switched CM off and "calibrated" their
output to work well with just one print shop.

> So, may it be, that this - „all graphics artist you know … switch off
color management - is the real cause why GIMP doesn’t have a working color
management in 2016? You don’t know anybody who uses it and so you don’t see
any need to implement it?

Please calm down.

> > The sane choice way to let users disable it, rather than
> > forcing it upon them
>
> Well, this may be the sane choice for _you_ but, please, don’t tell
others - your target audience: professional photographers, artists and
scientists -  what their sane choice has to be.

You are pretty much saying that it is wrong to force freedom of choice upon
people. This doesn't make any sense.

Ale
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Re: [Gimp-developer] New Image/Color Management option

2016-05-12 Thread Simone Karin Lehmann

> Am 12.05.2016 um 21:56 schrieb Michael Natterer :
> 
> 
>> What is the purpose of this new option? It doesn't do the same thing
>> as 
>> going to Preferences and selecting "Color Management/Mode of 
>> operation/No color management".
> 
> The prefs option is for display color management, and will soon
> only be a default for a per-display switch.
> 
> The option in Image -> New allows to disable color management
> and whatever color management transforms on a per-image base.
> 

Woooh, I can’t believe it! You’re saying that

> This is mainly because almost nobody understands what this
> whole color stuff is about at all.

Is this how you think about all the people who use GIMP? That almost none of 
them understands color management? 

May I remind you of your product vision? -> 
http://gui.gimp.org/index.php/GIMP_UI_Redesign#product_vision

"GIMP is a platform for programming cutting-edge image processing algorithms, 
by scientists and artists"

Do you really think, that these targeted audience, your targerted audience, 
doesn’t know what color management is all a bout? Or, sorry to say so, is it 
that _you_ are the one that does not know waht different aspects of color 
management have to be taken care of in an image editor? 

> All (sic!) graphics artists
> I know and have asked switch off color management entirely
> in Photoshop because it's this confusing thing that changes
> colors in an unpredictable way  (which is not surprising
> given the cluelessness).

So, this is how you think about your target users? They are clueless? Your 
target users - professional artists and photographers - switch off color 
management, because it’s confusing them? Or is  it that the users _you_ know 
and the users who claim theirselves as professionals do not know what color 
manangement is and don’t know how to handle it?

So, may it be, that this - „all graphics artist you know … switch off color 
management - is the real cause why GIMP doesn’t have a working color management 
in 2016? You don’t know anybody who uses it and so you don’t see any need to 
implement it? 
Come on, let’s face reality. It’s 2016 and almost all software for image or 
photo editing I know is capable to handle color management. Yet GIMP 2.8.x is 
still broken in some parts….

Trust me, there are a lot, a really lot of professional users, artists, 
scientists and photographers - again I’ll remind you that these are your target 
audience as described in your product vision - who know what color management 
is about and who use it and want to use it in a correct and predictable way. 
Count me one of them.

> 
> Most people dealing with photos do know their colors however
> and have it on, and have the right profiles.
> 
> The sane choice way to let users disable it, rather than
> forcing it upon them

Well, this may be the sane choice for _you_ but, please, don’t tell others - 
your target audience: professional photographers, artists and scientists -  
what their sane choice has to be.

Regards
Simone Karin



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Re: [Gimp-developer] New Image/Color Management option

2016-05-12 Thread Michael Natterer
On Thu, 2016-05-12 at 16:28 -0400, Elle Stone wrote:
> On 05/12/2016 03:56 PM, Michael Natterer wrote:
> > 
> > The prefs option is for display color management, and will soon
> > only be a default for a per-display switch.
> What does the above sentence mean?
> 
> Specifically what does "per-display switch" mean? Is this for 
> multi-monitor support? Or something else?

I should have written "image window" not "display", that's an
internal code term. There will color management options per
image view, so you can e.g. see the normally color managed
and the proof version side by side.

--Mitch

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Re: [Gimp-developer] New Image/Color Management option

2016-05-12 Thread Elle Stone

On 05/12/2016 03:56 PM, Michael Natterer wrote:

The prefs option is for display color management, and will soon
only be a default for a per-display switch.


What does the above sentence mean?

Specifically what does "per-display switch" mean? Is this for 
multi-monitor support? Or something else?


Best,
Elle



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Re: [Gimp-developer] New Image/Color Management option

2016-05-12 Thread Pat David
On Thursday, May 12, 2016, Michael Natterer  wrote:

>
> Most people dealing with photos do know their colors however
> and have it on, and have the right profiles.
>
> The sane choice way to let users disable it, rather than
> forcing it upon them.
>
>
Agreed.


-- 
pat david
http://blog.patdavid.net
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Re: [Gimp-developer] New Image/Color Management option

2016-05-12 Thread Michael Natterer
On Thu, 2016-05-12 at 08:46 -0400, Elle Stone wrote:
> There is a new "Image/Color Management" option to "Enable Color 
> Management". The option is checked by default. For sRGB images,
> checking 
> or unchecking the option doesn't seem to make any difference.

Exactly, even without a profile, pixels have some meaning. And
in GIMP, the "default" meaning is sRGB.

> What is the purpose of this new option? It doesn't do the same thing
> as 
> going to Preferences and selecting "Color Management/Mode of 
> operation/No color management".

The prefs option is for display color management, and will soon
only be a default for a per-display switch.

The option in Image -> New allows to disable color management
and whatever color management transforms on a per-image base.

This is mainly because almost nobody understands what this
whole color stuff is about at all. All (sic!) graphics artists
I know and have asked switch off color management entirely
in Photoshop because it's this confusing thing that changes
colors in an unpredictable way  (which is not surprising
given the cluelessness).

Most people dealing with photos do know their colors however
and have it on, and have the right profiles.

The sane choice way to let users disable it, rather than
forcing it upon them.

Regards,
--Mitch

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Re: [Gimp-developer] New Image/Color Management option

2016-05-12 Thread Elle Stone

On 05/12/2016 09:05 AM, Alexandre Prokoudine wrote:

On Thu, May 12, 2016 at 3:46 PM, Elle Stone wrote:

There is a new "Image/Color Management" option to "Enable Color Management".
The option is checked by default. For sRGB images, checking or unchecking
the option doesn't seem to make any difference.

What is the purpose of this new option? It doesn't do the same thing as
going to Preferences and selecting "Color Management/Mode of operation/No
color management".


It isn't supposed to. This is a per-image option.


I do already understand that the new option "does something different" 
than the option in Preferences.


I do already understand that the new option is a "per image" option.

What I don't understand is why and how the new option produces different 
results for sRGB images vs images in other RGB color spaces.


Also, what is/are the use case(s) for disabling color management on a 
"per image" basis?


Best,
Elle

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