Re: [darktable-user] Channel mixer bug?

[Bill Martz]

I didn't remember exactly what it was about, but I found the post, and it
was about converting to BW:
https://discuss.pixls.us/t/black-printing-problem/19048/6

I appreciate the explanation.

On Fri, Sep 4, 2020 at 10:42 PM Matt Maguire 
wrote:

> Le sam. 5 sept. 2020 à 11:55, Bill Martz 
> a écrit :
>
>> I will have to dig through my Pixls posts to find this, but I posted
>> about a problem using channel mixer, and I received that suggestion in
>> reply. I tried it, and it fixed the problem as far as I could tell. I will
>> see if I can find it tomorrow.
>>
>
> Putting the channel mixer after the filmic module will "solve" the
> clipping problem, but remember that channel mixer is doing a matrix
> multiplication. When you multiply in a linear space like we have before
> fimlic, you are doing a scaling, but when you multiply in a log space like
> what we have after filmic, it becomes like raising the values to a power,
> which will mess around with the contrast. If the adjustments are small,
> maybe this won't matter too much in practice, but I was just warning from a
> maths perspective, it could become problematic especially for larger
> adjustmentd. The ideal situation is to do those sorts of scaling and
> rotation transformations in a linear space without doing any clipping, then
> at the end of those transforms you apply your non-linear look transform
> using filmic/tonecurve/basecurve/whatever.
>


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Re: [darktable-user] Channel mixer bug?

[Matt Maguire]

Le sam. 5 sept. 2020 à 11:55, Bill Martz  a
écrit :

> I will have to dig through my Pixls posts to find this, but I posted about
> a problem using channel mixer, and I received that suggestion in reply. I
> tried it, and it fixed the problem as far as I could tell. I will see if I
> can find it tomorrow.
>

Putting the channel mixer after the filmic module will "solve" the clipping
problem, but remember that channel mixer is doing a matrix multiplication.
When you multiply in a linear space like we have before fimlic, you are
doing a scaling, but when you multiply in a log space like what we have
after filmic, it becomes like raising the values to a power, which will
mess around with the contrast. If the adjustments are small, maybe this
won't matter too much in practice, but I was just warning from a maths
perspective, it could become problematic especially for larger adjustmentd.
The ideal situation is to do those sorts of scaling and rotation
transformations in a linear space without doing any clipping, then at the
end of those transforms you apply your non-linear look transform using
filmic/tonecurve/basecurve/whatever.


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Re: [darktable-user] Channel mixer bug?

[Bill Martz]

I will have to dig through my Pixls posts to find this, but I posted about
a problem using channel mixer, and I received that suggestion in reply. I
tried it, and it fixed the problem as far as I could tell. I will see if I
can find it tomorrow.

On Fri, Sep 4, 2020 at 2:36 PM Matt Maguire 
wrote:

> Le sam. 5 sept. 2020 à 03:55, Bill Martz 
> a écrit :
>
>> Try moving channel mixer above filmic rgb in the list on the right side.
>> Ctrl+Shft+right click on channel mixer module. Then move up the list. I
>> sometimes have trouble getting it to land exactly where I want it to be, so
>> if it is not where you want it, move it again.
>>
>
> Not sure that is really advisable. The transfer curve of the filmic module
> will avoid you running afoul of the clipping function, but it will also
> apply a gamma power function to the data, which means you are no longer
> working in a linear space, and performing an RGB matrix multiplication with
> channel mixer at that point means you could get different amounts of hue
> shift at different brightness levels, which would make it quite tricky to
> control.
>


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Re: [darktable-user] Channel mixer bug?

[Matt Maguire]

Le sam. 5 sept. 2020 à 03:55, Bill Martz  a
écrit :

> Try moving channel mixer above filmic rgb in the list on the right side.
> Ctrl+Shft+right click on channel mixer module. Then move up the list. I
> sometimes have trouble getting it to land exactly where I want it to be, so
> if it is not where you want it, move it again.
>

Not sure that is really advisable. The transfer curve of the filmic module
will avoid you running afoul of the clipping function, but it will also
apply a gamma power function to the data, which means you are no longer
working in a linear space, and performing an RGB matrix multiplication with
channel mixer at that point means you could get different amounts of hue
shift at different brightness levels, which would make it quite tricky to
control.


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Re: [darktable-user] Channel mixer bug?

[Bill Martz]

Try moving channel mixer above filmic rgb in the list on the right side.
Ctrl+Shft+right click on channel mixer module. Then move up the list. I
sometimes have trouble getting it to land exactly where I want it to be, so
if it is not where you want it, move it again.

On Thu, Sep 3, 2020 at 12:05 PM Mikael Ståldal  wrote:

> After playing around with the channel mixer on some pictures, I get an
> odd effect sometimes. Just enabling the module with default settings
> sometimes affects the picture, the histogram jumps to the left and I
> lose detail in the highlights. Seems to happen when I also use filmic
> RGB. Is this intended, or a bug?
>
>
> On 2020-09-01 21:04, Mikael Ståldal wrote:
> > I have tried to use the channel mixer module, but I don't quite
> > understand it. I have only been able to effectively use the presets.
> >
> > I have read the user manual, but it didn't help much.
> >
> > I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
> > but it seems like Bruce Williams was quite confused as well.
> >
> > Any suggestions for documentation or tutorials?
> >
> 
>
> >
> > darktable user mailing list
> > to unsubscribe send a mail to
> > darktable-user+unsubscr...@lists.darktable.org
> >
>
> 
> darktable user mailing list
> to unsubscribe send a mail to
> darktable-user+unsubscr...@lists.darktable.org
>
>


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Re: [darktable-user] Channel mixer bug?

[William Ferguson]

https://github.com/darktable-org/darktable/issues/5578

On Thu, Sep 3, 2020 at 1:18 PM Mikael Ståldal  wrote:

> Thanks, good to know. (Would be nice if this was documented though.)
>
> /Mikael
>
>
> On 2020-09-03 18:12, Matt Maguire wrote:
> > The problem is that the channel mixer has a clamping function which
> > limits the values that are allowed to pass through. This is not
> > appropriate behaviour for the scene-referred part of the pixel pipe, as
> > it can result in exactly the symptoms you report. The devs are aware of
> > this, and there are multiple PRs looking at how to solve this. I would
> > expect that in darktable 3.4 they should settle on one of the solutions
> > being proposed.
> >
> > On Fri, 4 Sep 2020 at 02:06, Mikael Ståldal  > > wrote:
> >
> > After playing around with the channel mixer on some pictures, I get
> an
> > odd effect sometimes. Just enabling the module with default settings
> > sometimes affects the picture, the histogram jumps to the left and I
> > lose detail in the highlights. Seems to happen when I also use filmic
> > RGB. Is this intended, or a bug?
> >
> >
> > On 2020-09-01 21:04, Mikael Ståldal wrote:
> >  > I have tried to use the channel mixer module, but I don't quite
> >  > understand it. I have only been able to effectively use the
> presets.
> >  >
> >  > I have read the user manual, but it didn't help much.
> >  >
> >  > I also looked at this video:
> > https://www.youtube.com/watch?v=ZGvkSTjjtMw
> >  > but it seems like Bruce Williams was quite confused as well.
> >  >
> >  > Any suggestions for documentation or tutorials?
> >  >
> >
>  
> >
> >  >
> >  > darktable user mailing list
> >  > to unsubscribe send a mail to
> >  > darktable-user+unsubscr...@lists.darktable.org
> > 
> >  >
> >
>  
> > darktable user mailing list
> > to unsubscribe send a mail to
> > darktable-user+unsubscr...@lists.darktable.org
> > 
> >
> >
> >
> 
>
> > darktable user mailing list to unsubscribe send a mail to
> > darktable-user+unsubscr...@lists.darktable.org
>
> 
> darktable user mailing list
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Re: [darktable-user] Channel mixer bug?

[Mikael Ståldal]

Thanks, good to know. (Would be nice if this was documented though.)

/Mikael


On 2020-09-03 18:12, Matt Maguire wrote:
The problem is that the channel mixer has a clamping function which 
limits the values that are allowed to pass through. This is not 
appropriate behaviour for the scene-referred part of the pixel pipe, as 
it can result in exactly the symptoms you report. The devs are aware of 
this, and there are multiple PRs looking at how to solve this. I would 
expect that in darktable 3.4 they should settle on one of the solutions 
being proposed.


On Fri, 4 Sep 2020 at 02:06, Mikael Ståldal > wrote:


After playing around with the channel mixer on some pictures, I get an
odd effect sometimes. Just enabling the module with default settings
sometimes affects the picture, the histogram jumps to the left and I
lose detail in the highlights. Seems to happen when I also use filmic
RGB. Is this intended, or a bug?


On 2020-09-01 21:04, Mikael Ståldal wrote:
 > I have tried to use the channel mixer module, but I don't quite
 > understand it. I have only been able to effectively use the presets.
 >
 > I have read the user manual, but it didn't help much.
 >
 > I also looked at this video:
https://www.youtube.com/watch?v=ZGvkSTjjtMw
 > but it seems like Bruce Williams was quite confused as well.
 >
 > Any suggestions for documentation or tutorials?
 >


 >
 > darktable user mailing list
 > to unsubscribe send a mail to
 > darktable-user+unsubscr...@lists.darktable.org

 >

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Re: [darktable-user] Channel mixer bug?

[Matt Maguire]

Le ven. 4 sept. 2020 à 02:21, Graham Byrnes  a écrit :

> If you stick to "graymode" or the color modes (outputs R,G,B) it should be
> fine: there is a bug that clips large signals to 1, which is really a bug
> but has potentially been incorporated in many models. Certainly if you keep
> the sum of values to 1, it should rarely cause a problem.
>


Except that the topic of this thread was exactly that the OP is
experiencing problems even when leaving the sliders at defaults in channel
mixer (where it is just applying an identity matrix with the sum of each
row being 1). So, to try to claim this clipping behaviour (I say behaviour
rather than bug) rarely causes a problem is not really true. BTW, the gray
mode is also subject to this clipping behaviour. The HSL mode clipping
implementation really is broken, and there I would absolutely call it a bug.

In Aurélien's article "Darktable 3.0 for Dummies: hardcore edition", he
admits he has been using a hacked version of the channel mixer that takes
out the clipping behaviour. In order to bring that into an official release
though, it needs to be done in a robust way, and there have been
discussions on github on how to achieve exactly that.


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Re: [darktable-user] Channel mixer bug?

[Graham Byrnes]

If you stick to "graymode" or the color modes (outputs R,G,B) it should be
fine: there is a bug that clips large signals to 1, which is really a bug
but has potentially been incorporated in many models. Certainly if you keep
the sum of values to 1, it should rarely cause a problem.

For HSL, yes, there may be a problem... but I'd be surprised if it is
related to filmic. If you want to do non-linear colour things, I'd suggest
colorcorrect.

The question really is what you want to achieve.

Cheers,
Graham


Le jeu. 3 sept. 2020 à 18:05, Mikael Ståldal  a écrit :

> After playing around with the channel mixer on some pictures, I get an
> odd effect sometimes. Just enabling the module with default settings
> sometimes affects the picture, the histogram jumps to the left and I
> lose detail in the highlights. Seems to happen when I also use filmic
> RGB. Is this intended, or a bug?
>
>
> On 2020-09-01 21:04, Mikael Ståldal wrote:
> > I have tried to use the channel mixer module, but I don't quite
> > understand it. I have only been able to effectively use the presets.
> >
> > I have read the user manual, but it didn't help much.
> >
> > I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
> > but it seems like Bruce Williams was quite confused as well.
> >
> > Any suggestions for documentation or tutorials?
> >
> 
>
> >
> > darktable user mailing list
> > to unsubscribe send a mail to
> > darktable-user+unsubscr...@lists.darktable.org
> >
>
> 
> darktable user mailing list
> to unsubscribe send a mail to
> darktable-user+unsubscr...@lists.darktable.org
>
>

-- 
Graham Byrnes
Bron (Lyon), France
Mes photos: https://500px.com/grahambyrnes


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Re: [darktable-user] Channel mixer bug?

[Matt Maguire]

The problem is that the channel mixer has a clamping function which limits
the values that are allowed to pass through. This is not appropriate
behaviour for the scene-referred part of the pixel pipe, as it can result
in exactly the symptoms you report. The devs are aware of this, and there
are multiple PRs looking at how to solve this. I would expect that in
darktable 3.4 they should settle on one of the solutions being proposed.

On Fri, 4 Sep 2020 at 02:06, Mikael Ståldal  wrote:

> After playing around with the channel mixer on some pictures, I get an
> odd effect sometimes. Just enabling the module with default settings
> sometimes affects the picture, the histogram jumps to the left and I
> lose detail in the highlights. Seems to happen when I also use filmic
> RGB. Is this intended, or a bug?
>
>
> On 2020-09-01 21:04, Mikael Ståldal wrote:
> > I have tried to use the channel mixer module, but I don't quite
> > understand it. I have only been able to effectively use the presets.
> >
> > I have read the user manual, but it didn't help much.
> >
> > I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
> > but it seems like Bruce Williams was quite confused as well.
> >
> > Any suggestions for documentation or tutorials?
> >
> 
>
> >
> > darktable user mailing list
> > to unsubscribe send a mail to
> > darktable-user+unsubscr...@lists.darktable.org
> >
>
> 
> darktable user mailing list
> to unsubscribe send a mail to
> darktable-user+unsubscr...@lists.darktable.org
>
>


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Re: [darktable-user] Channel mixer bug?

[Mikael Ståldal]

After playing around with the channel mixer on some pictures, I get an 
odd effect sometimes. Just enabling the module with default settings 
sometimes affects the picture, the histogram jumps to the left and I 
lose detail in the highlights. Seems to happen when I also use filmic 
RGB. Is this intended, or a bug?



On 2020-09-01 21:04, Mikael Ståldal wrote:
I have tried to use the channel mixer module, but I don't quite 
understand it. I have only been able to effectively use the presets.


I have read the user manual, but it didn't help much.

I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
but it seems like Bruce Williams was quite confused as well.

Any suggestions for documentation or tutorials?
 


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Re: [darktable-user] Channel mixer

[Bill Martz]

The channel mixer in dt, as it is in Raw Therapee and GIMP, is a GUI. What
you need to understand is mixing. Here's a video that has the use of
channel mixer at the beginning of the editing.
https://www.youtube.com/watch?v=bUP1TxVeL44

Here's a guide that I developed to help me understand what happens:

*Red channel*:

Increase green slider, which increases red where there is green and
therefore *the hue shifts to* *yellow* until you get to blue, and then *the
hue shifts to* *magenta*.

Decrease green slider, which decreases red where there is yellow and
therefore *increases* *green*.

Increase blue slider, which increases red where there is blue and
therefore *the
hue shifts to* *magenta* until you get to green, and then *the hue shifts
to* *yellow*.

Decrease blue slider, which decreases red where there is magenta and
therefore *increases* *blue*.

Increase red slider, and *the hue shifts to* *yellow* where there is green
mixed with red and *the hue shifts to* *magenta* where there is blue mixed
with red.

Decrease red slider, which decreases red and *increases* *green* where
there is cyan and *increases* *blue* where there is magenta.

*Green channel*:

Increase red slider, which increases green where there is red and
therefore *the
hue shifts to* *yellow* until you get to blue, and then *the hue shifts to*
*cyan*.

Decrease red slider, which decreases green where there is yellow and
therefore *increases* *red*.

Increase blue slider, which increases green where there is blue and
therefore *the hue shifts to* *cyan* until you get to red, and then *the
hue shifts to* *yellow*.

Decrease blue slider, which decreases green where there is cyan and
therefore *increases* *blue*.

Increase green slider, and *the hue shifts to* *cyan* where there is blue
and *the hue shifts to* *yellow* where there is red.

Decrease green slider, which decreases green and *increases* *red* where
there is yellow and *increases* *blue* where there is cyan.

*Blue channel*:

Increase red slider, which increases blue where there is red and therefore *the
hue shifts to* *magenta* until you get to green, and then *the hue shifts
to* *cyan*.

Decrease red slider, which decreases blue where there is magenta and
therefore *increases* *red*.

Increase green slider, which increases blue where there is green and
therefore *the hue shifts to* *cyan* until you get to red, and then *the
hue shifts to* *magenta*.

Decrease green slider, which decreases green where there is cyan and
therefore *increases* *green*.

Increase blue slider, which *the hue shifts to* *cyan* where there is green
and *the hue shifts to* *magenta* where there is red.

Decrease blue slider, which decreases blue and *increases* *red* where
there is magenta and *increases* *green* where there is cyan.





On Wed, Sep 2, 2020 at 9:26 AM Mikael Ståldal  wrote:

> Thanks, but those are not about Darktable:
>
> https://discuss.pixls.us/t/please-help-me-to-understand-channel-mixer/665
>
> https://www.youtube.com/watch?v=zgTLw31PVNs
>
>
> On 2020-09-02 14:23, Bill Martz wrote:
> > Here are some links:
> >
> >
> https://discuss.pixls.us/t/mastering-color-with-lab-tone-curves-revisited/19854/17
> >
> https://discuss.pixls.us/t/please-help-me-to-understand-channel-mixer/665
> > https://www.youtube.com/watch?v=zgTLw31PVNs
> > https://discuss.pixls.us/t/swift-play-with-the-channel-mixer/17244
> > https://discuss.pixls.us/t/using-the-waveform-in-darktable/17427/5
> >
> > There is a pdf at the first link that I recommend you download and look
> at.
> >
> > On Tue, Sep 1, 2020 at 3:05 PM Mikael Ståldal  > > wrote:
> >
> > I have tried to use the channel mixer module, but I don't quite
> > understand it. I have only been able to effectively use the presets.
> >
> > I have read the user manual, but it didn't help much.
> >
> > I also looked at this video:
> https://www.youtube.com/watch?v=ZGvkSTjjtMw
> > but it seems like Bruce Williams was quite confused as well.
> >
> > Any suggestions for documentation or tutorials?
> >
>  
> > darktable user mailing list
> > to unsubscribe send a mail to
> > darktable-user+unsubscr...@lists.darktable.org
> > 
> >
>


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Re: [darktable-user] Channel mixer

[Patrick Shanahan]

* Mikael Ståldal  [09-02-20 09:32]:
> Thanks, but those are not about Darktable:
> 
> https://discuss.pixls.us/t/please-help-me-to-understand-channel-mixer/665
> 
> https://www.youtube.com/watch?v=zgTLw31PVNs
> 
> 
> On 2020-09-02 14:23, Bill Martz wrote:
> > Here are some links:
> > 
> > https://discuss.pixls.us/t/mastering-color-with-lab-tone-curves-revisited/19854/17
> > https://discuss.pixls.us/t/please-help-me-to-understand-channel-mixer/665
> > https://www.youtube.com/watch?v=zgTLw31PVNs
> > https://discuss.pixls.us/t/swift-play-with-the-channel-mixer/17244
> > https://discuss.pixls.us/t/using-the-waveform-in-darktable/17427/5
> > 
> > There is a pdf at the first link that I recommend you download and look at.
> > 
> > On Tue, Sep 1, 2020 at 3:05 PM Mikael Ståldal  > > wrote:
> > 
> > I have tried to use the channel mixer module, but I don't quite
> > understand it. I have only been able to effectively use the presets.
> > 
> > I have read the user manual, but it didn't help much.
> > 
> > I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
> > but it seems like Bruce Williams was quite confused as well.
> > 
> > Any suggestions for documentation or tutorials?
> > 
> > 
> > darktable user mailing list
> > to unsubscribe send a mail to
> > darktable-user+unsubscr...@lists.darktable.org
> > 

while channel mixer modules/apps may vary in look, operations are similar. 
You can learn from the suggestion rather than to summarily dismiss it.

-- 
(paka)Patrick Shanahan   Plainfield, Indiana, USA  @ptilopteri
http://en.opensuse.orgopenSUSE Community Memberfacebook/ptilopteri
Photos: http://wahoo.no-ip.org/piwigo   paka @ IRCnet freenode

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Re: [darktable-user] Channel mixer

[Mikael Ståldal]

Thanks, but those are not about Darktable:

https://discuss.pixls.us/t/please-help-me-to-understand-channel-mixer/665

https://www.youtube.com/watch?v=zgTLw31PVNs


On 2020-09-02 14:23, Bill Martz wrote:

Here are some links:

https://discuss.pixls.us/t/mastering-color-with-lab-tone-curves-revisited/19854/17
https://discuss.pixls.us/t/please-help-me-to-understand-channel-mixer/665
https://www.youtube.com/watch?v=zgTLw31PVNs
https://discuss.pixls.us/t/swift-play-with-the-channel-mixer/17244
https://discuss.pixls.us/t/using-the-waveform-in-darktable/17427/5

There is a pdf at the first link that I recommend you download and look at.

On Tue, Sep 1, 2020 at 3:05 PM Mikael Ståldal > wrote:


I have tried to use the channel mixer module, but I don't quite
understand it. I have only been able to effectively use the presets.

I have read the user manual, but it didn't help much.

I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
but it seems like Bruce Williams was quite confused as well.

Any suggestions for documentation or tutorials?

darktable user mailing list
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darktable-user+unsubscr...@lists.darktable.org




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Re: [darktable-user] Channel mixer

[Bill Martz]

Here are some links:

https://discuss.pixls.us/t/mastering-color-with-lab-tone-curves-revisited/19854/17
https://discuss.pixls.us/t/please-help-me-to-understand-channel-mixer/665
https://www.youtube.com/watch?v=zgTLw31PVNs
https://discuss.pixls.us/t/swift-play-with-the-channel-mixer/17244
https://discuss.pixls.us/t/using-the-waveform-in-darktable/17427/5

There is a pdf at the first link that I recommend you download and look at.

On Tue, Sep 1, 2020 at 3:05 PM Mikael Ståldal  wrote:

> I have tried to use the channel mixer module, but I don't quite
> understand it. I have only been able to effectively use the presets.
>
> I have read the user manual, but it didn't help much.
>
> I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
> but it seems like Bruce Williams was quite confused as well.
>
> Any suggestions for documentation or tutorials?
>
> 
> darktable user mailing list
> to unsubscribe send a mail to
> darktable-user+unsubscr...@lists.darktable.org
>
>


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Re: [darktable-user] Channel mixer

[Matt Maguire]

The channel mixer is basically 3 modules in 1:
- using the red, green and blue destinations, it allows you to effectively
do a matrix multiplication on the [R,G,B] vectors:
[Rout]   [Rr Rg Rb]   [Rin]
[Gout] = [Gr Gg Gb] x [Gin]
[Bout]   [Br Bg Bb]   [Bin]

You use the sliders on the red, green & blue destination tabs to input the
9 coefficients of the matrix. Transformations between (linear) colour
spaces are usually achieved by matrix multiplications, and you can use such
a linear transform to "tweak the primary colours" of your
colourspace (basically transform to a different colour space with slightly
different primary colours). This is a fairly technical thing, and if you
try to find suitable coefficients by "trial and error" I think it may be
quite difficult to use unless you keep the adjustments very small, or use
it with a mask. The following article has an example where this feature of
channel mixer was used together with a mask to adjust the blue light from
LEDs to bring them back into gamut.
https://discuss.pixls.us/t/darktable-3-0-for-dummies-hardcore-edition/15864

- converting the image to monochrome. Basically, for each pixel it is
setting the R,G,B values to the same value (which is a well-behaved
colourspace results in some shade of grey). There are different strategies
for how you decide which [x,x,x] value to map an [R,G,B] vector to (eg.
averaging, max, etc.). Here I think there is nothing wrong with just using
the presets to find a suitable look.

- using [R,G,B] values to influence Hue, Saturation & Lightness (HSL). I'm
hard pressed to understand what you would use this for in practice, and I
saw a discussion on github which seemed to indicate the implementation here
may even be broken.


On Wed, 2 Sep 2020 at 05:05, Mikael Ståldal  wrote:

> I have tried to use the channel mixer module, but I don't quite
> understand it. I have only been able to effectively use the presets.
>
> I have read the user manual, but it didn't help much.
>
> I also looked at this video: https://www.youtube.com/watch?v=ZGvkSTjjtMw
> but it seems like Bruce Williams was quite confused as well.
>
> Any suggestions for documentation or tutorials?
>
> 
> darktable user mailing list
> to unsubscribe send a mail to
> darktable-user+unsubscr...@lists.darktable.org
>
>


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Re: [darktable-user] Channel mixer

[KOVÁCS István]

On Tue, 1 Sep 2020 at 21:05, Mikael Ståldal  wrote:
>
> I have tried to use the channel mixer module, but I don't quite
> understand it. I have only been able to effectively use the presets.
> [...]
> Any suggestions for documentation or tutorials?

You could try this:
https://discuss.pixls.us/t/mastering-color-with-lab-tone-curves-revisited/19854/12
There's also a PDF, but it'll probably make more sense if you read the
thread as well. The PDF is linked to the following answer:
https://discuss.pixls.us/t/mastering-color-with-lab-tone-curves-revisited/19854/26

Kofa

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Re: [darktable-user] Channel Mixer => Levels and Historgram are not aligned

[Michael Staats]

On 11/08/2019 20:27, jys wrote:
> On Sun, Aug 11, 2019, at 09:01, Michael Staats wrote:
>
>> Am I missing something, or is the histogram in "levels" confused by the 
>> (admittedly extreme) channel setting?
>
> The histogram in "levels" is showing what that module is seeing as input. The 
> global histogram is reflecting not only any changes you make to levels, but 
> also any other operations which happen later in the "pipe" (higher in the 
> module list) than "levels"... this includes the channel mixer module.
>

Hi
Thanks, hmm, yes, this explains it... It's a bit confusing, but ok, now
that I know it's "works as designed", I can of course work with "levels"
and just check the final histogram.
Best regards,
Michael

--
Michael Staats
michael.sta...@gmx.de

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Re: [darktable-user] Channel Mixer => Levels and Historgram are not aligned

[jys]

On Sun, Aug 11, 2019, at 09:01, Michael Staats wrote:

> Am I missing something, or is the histogram in "levels" confused by the 
> (admittedly extreme) channel setting?

The histogram in "levels" is showing what that module is seeing as input. The 
global histogram is reflecting not only any changes you make to levels, but 
also any other operations which happen later in the "pipe" (higher in the 
module list) than "levels"... this includes the channel mixer module.

-- 
jys

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Re: Re: Re: Fwd: Re: [darktable-user] Channel Mixer Oddity

[Jean-Luc Coulon (f5ibh)]

Hello Alan

I have had some problems in the past due to a random problem with the right
button of my mouse.

I had very strange behaviours and I was unable to rotate an image in the
"crop and rotate module".

Maybe yous hould control your mouse, especally if it is Logitech (the best
way is to try an other one for a while).

... just in case of...

J-L

2016-07-11 20:12 GMT+02:00 A. Huntley <alan.hunt...@cox.net>:

> Hello Jean-Luc,
>
> Just to be absolutely clear...I am not missing the right-click. I've tried
> everything I can think of and I cannot do *any* entry into this field.
> What's additionally odd is that the box will often stay open even when I
> close the Channel Mixer dialog or return to lighttable because I hit a dot.
> It really makes me think that on Mac GTK3 is loosing focus, since I have to
> click on something else to close the box.
>
> Regards,
> Alan
>
>
> -------- Forwarded Message ----
> Subject: Re: Re: Fwd: Re: [darktable-user] Channel Mixer Oddity
> Date: Mon, 11 Jul 2016 18:57:39 +0200
> From: Jean-Luc Coulon (f5ibh) <jean.luc.cou...@gmail.com>
> <jean.luc.cou...@gmail.com>
> CC: darktable-user <darktable-user@lists.darktable.org>
> <darktable-user@lists.darktable.org>
>
>
> Hi,
>
> Tobias said,
> "Regarding the problem with the '.', it seems that for some reason the
> focus
> indeed is first passed to the parent window instead of the popup directly.
> I
> suppose other keys (like, numbers) are working when typing?"
>
> Just to add some informations:
>
> I use quite often this module and most of the time, everything is fine.
> (BTW it accepts both , [comma] or . [dot] as the decimal delimiter with my
> french locale). Time to time I've the problem of darktable switching back
> to the ligthtable.
>
> Normally, I do a right-click and the I enter the value (or move the widget
> control) and everything is fine.
>
> But *if I miss the right-click*, entering directly a dot (decimal point),
> then it switches back to the lighttable. This is perfectly repeatable.
>
> If I enter the coma... it does nothing which is fine.
>
> I never remarked this before, because I never missed the right-click...
> I've just torured it a bit to test.
>
> I use Debian sid, with gnome/gtk-3.0 and git/master version.
>
> Regards
>
> Jean-Luc
>
>
>
> 
> darktable user mailing list to unsubscribe send a mail to
> darktable-user+unsubscr...@lists.darktable.org
>
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2016.0.7640 / Virus Database: 4613/12594 - Release Date: 07/10/16
>
> 
> darktable user mailing list to unsubscribe send a mail to
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>


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Fwd: Re: Re: Fwd: Re: [darktable-user] Channel Mixer Oddity

[A. Huntley]

Hello Jean-Luc,

Just to be absolutely clear...I am not missing the right-click. I've 
tried everything I can think of and I cannot do _any_ entry into this 
field. What's additionally odd is that the box will often stay open even 
when I close the Channel Mixer dialog or return to lighttable because I 
hit a dot. It really makes me think that on Mac GTK3 is loosing focus, 
since I have to click on something else to close the box.


Regards,
Alan


 Forwarded Message 
Subject:Re: Re: Fwd: Re: [darktable-user] Channel Mixer Oddity
Date:   Mon, 11 Jul 2016 18:57:39 +0200
From:   Jean-Luc Coulon (f5ibh) <jean.luc.cou...@gmail.com>
CC: darktable-user <darktable-user@lists.darktable.org>



Hi,

Tobias said,
"Regarding the problem with the '.', it seems that for some reason the focus
indeed is first passed to the parent window instead of the popup directly. I
suppose other keys (like, numbers) are working when typing?"

Just to add some informations:

I use quite often this module and most of the time, everything is fine.
(BTW it accepts both , [comma] or . [dot] as the decimal delimiter with 
my french locale). Time to time I've the problem of darktable switching 
back to the ligthtable.


Normally, I do a right-click and the I enter the value (or move the 
widget control) and everything is fine.


But *if I miss the right-click*, entering directly a dot (decimal 
point), then it switches back to the lighttable. This is perfectly 
repeatable.


If I enter the coma... it does nothing which is fine.

I never remarked this before, because I never missed the right-click... 
I've just torured it a bit to test.


I use Debian sid, with gnome/gtk-3.0 and git/master version.

Regards

Jean-Luc



 
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darktable-user+unsubscr...@lists.darktable.org


No virus found in this message.
Checked by AVG - www.avg.com <http://www.avg.com>
Version: 2016.0.7640 / Virus Database: 4613/12594 - Release Date: 07/10/16



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Re: Re: Fwd: Re: [darktable-user] Channel Mixer Oddity

[Jean-Luc Coulon (f5ibh)]

Hi,

Tobias said,
"Regarding the problem with the '.', it seems that for some reason the focus
indeed is first passed to the parent window instead of the popup directly. I
suppose other keys (like, numbers) are working when typing?"

Just to add some informations:

I use quite often this module and most of the time, everything is fine.
(BTW it accepts both , [comma] or . [dot] as the decimal delimiter with my
french locale). Time to time I've the problem of darktable switching back
to the ligthtable.

Normally, I do a right-click and the I enter the value (or move the widget
control) and everything is fine.

But *if I miss the right-click*, entering directly a dot (decimal point),
then it switches back to the lighttable. This is perfectly repeatable.

If I enter the coma... it does nothing which is fine.

I never remarked this before, because I never missed the right-click...
I've just torured it a bit to test.

I use Debian sid, with gnome/gtk-3.0 and git/master version.

Regards

Jean-Luc


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Re: Fwd: Re: [darktable-user] Channel Mixer Oddity

[Tobias Ellinghaus]

On Freitag, 8. Juli 2016 13:04:26 CEST A. Huntley wrote:
> Nope...didn't work. I tried moving the mouse in/out a few times and even
> clicking on the entry field, but no go. What's additionally odd is if I
> right-click on the slider, the entry area has a blinking vertical bar
> for about 3 secs, and then it goes away! I haven't moved my mouse or
> anything. It definitely seems like a focus issue in that area. If it's a
> GTK3 issue, is this something the DT development team can even fix?

The cursor is only intended to be shown for 3 seconds or until the mouse is 
used to move the value to avoid visual clutter. We thought 3 seconds to be 
long enough to be a useful hint that you can type there.

Regarding the problem with the '.', it seems that for some reason the focus 
indeed is first passed to the parent window instead of the popup directly. I 
suppose other keys (like, numbers) are working when typing?

> Regards,
> Alan

Tobias

[...]

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Fwd: Re: [darktable-user] Channel Mixer Oddity

[A. Huntley]

:) :) Don't blame you a bit! It's really not a big deal because I can 
get close enough simply dragging the sliders. Perhaps, one day, this 
will be one of those mysterious things that automagically fixes itself.


Thanks for all your input.

Regards,
Alan


 Forwarded Message 
Subject:Re: [darktable-user] Channel Mixer Oddity
Date:   Sat, 9 Jul 2016 00:25:57 +0300
From:   para...@paraf.in
To: darktable-user@lists.darktable.org



Can? Of course, it's open source after all. Want? No, I'm sick of 
tracking down GTK bugs, they break stuff with every update anyway.


On 08 Jul 2016, at 23:04, A. Huntley <alan.hunt...@cox.net 
<mailto:alan.hunt...@cox.net>> wrote:


Nope...didn't work. I tried moving the mouse in/out a few times and 
even clicking on the entry field, but no go. What's additionally odd 
is if I right-click on the slider, the entry area has a blinking 
vertical bar for about 3 secs, and then it goes away! I haven't moved 
my mouse or anything. It definitely seems like a focus issue in that 
area. If it's a GTK3 issue, is this something the DT development team 
can even fix?


Regards,
Alan


 Forwarded Message 
Subject:    Re: [darktable-user] Channel Mixer Oddity
Date:   Fri, 8 Jul 2016 20:54:28 +0300
From:   para...@paraf.in
CC: darktable-user@lists.darktable.org



It's probably the focus issue GTK3 is having on Mac platform, try 
moving the mouse into the popup area, out and then back again, then 
type. Haven't tried myself though.


On 08 Jul 2016, at 20:49, A. Huntley <alan.hunt...@cox.net> wrote:

Please excuse my ignorance on how to use these users lists...I think 
I sent an earlier reply directly to Tobias. Trying to send to list 
now! ;)


Tobias,

I'm running OS X 10.11.5 and DT 2.0.5

Thank you.

Regards,
Alan


 Forwarded Message ----
Subject:    Re: [darktable-user] Channel Mixer Oddity
Date:   Fri, 08 Jul 2016 11:35:07 +0200
From:   Tobias Ellinghaus <m...@houz.org>
To: darktable-user@lists.darktable.org



On Donnerstag, 7. Juli 2016 11:27:54 CEST A. Huntley wrote:
> Hello All,

Hi.

> I'm trying to convert some files to B using the Channel Mixer and I'd
> like to enter specific values for R-G-B, as suggested in the User Manual
> for specific films. However, when I right-click to enter whatever value
> I need and see the blinking entry field (middle right side of the box)
> trying to enter, for example, .20 for the Red channel doesn't work. As
> soon as I hit period on my keyboard I'm tossed back into the lighttable.
> What am I doing wrong?

What window manager and what version of darktable are you using?

> Thank you for any help provided.
>
> Kind regards,
> AlanH

Tobias

 
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No virus found in this message.
Checked by AVG - www.avg.com <http://www.avg.com>
Version: 2016.0.7640 / Virus Database: 4613/12581 - Release Date: 07/08/16


 
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Re: [darktable-user] Channel Mixer Oddity

[parafin]

Can? Of course, it's open source after all. Want? No, I'm sick of tracking down 
GTK bugs, they break stuff with every update anyway.

> On 08 Jul 2016, at 23:04, A. Huntley <alan.hunt...@cox.net> wrote:
> 
> Nope...didn't work. I tried moving the mouse in/out a few times and even 
> clicking on the entry field, but no go. What's additionally odd is if I 
> right-click on the slider, the entry area has a blinking vertical bar for 
> about 3 secs, and then it goes away! I haven't moved my mouse or anything. It 
> definitely seems like a focus issue in that area. If it's a GTK3 issue, is 
> this something the DT development team can even fix?
> 
> Regards,
> Alan
> 
> 
> ---- Forwarded Message ----
> Subject:  Re: [darktable-user] Channel Mixer Oddity
> Date: Fri, 8 Jul 2016 20:54:28 +0300
> From: para...@paraf.in
> CC:   darktable-user@lists.darktable.org
> 
> It's probably the focus issue GTK3 is having on Mac platform, try moving the 
> mouse into the popup area, out and then back again, then type. Haven't tried 
> myself though.
> 
> On 08 Jul 2016, at 20:49, A. Huntley <alan.hunt...@cox.net> wrote:
> 
>> Please excuse my ignorance on how to use these users lists...I think I sent 
>> an earlier reply directly to Tobias. Trying to send to list now! ;)
>> 
>> Tobias,
>> 
>> I'm running OS X 10.11.5 and DT 2.0.5
>> 
>> Thank you.
>> 
>> Regards,
>> Alan
>> 
>> 
>>  Forwarded Message 
>> Subject: Re: [darktable-user] Channel Mixer Oddity
>> Date:Fri, 08 Jul 2016 11:35:07 +0200
>> From:Tobias Ellinghaus <m...@houz.org>
>> To:  darktable-user@lists.darktable.org
>> 
>> On Donnerstag, 7. Juli 2016 11:27:54 CEST A. Huntley wrote:
>> > Hello All,
>> 
>> Hi.
>> 
>> > I'm trying to convert some files to B using the Channel Mixer and I'd
>> > like to enter specific values for R-G-B, as suggested in the User Manual
>> > for specific films. However, when I right-click to enter whatever value
>> > I need and see the blinking entry field (middle right side of the box)
>> > trying to enter, for example, .20 for the Red channel doesn't work. As
>> > soon as I hit period on my keyboard I'm tossed back into the lighttable.
>> > What am I doing wrong?
>> 
>> What window manager and what version of darktable are you using?
>> 
>> > Thank you for any help provided.
>> > 
>> > Kind regards,
>> > AlanH
>> 
>> Tobias
>> 
>>  
>> darktable user mailing list to unsubscribe send a mail to 
>> darktable-user+unsubscr...@lists.darktable.org 
>> 
> 
>  
> darktable user mailing list to unsubscribe send a mail to 
> darktable-user+unsubscr...@lists.darktable.org 
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2016.0.7640 / Virus Database: 4613/12581 - Release Date: 07/08/16
> 
> 
>  
> darktable user mailing list to unsubscribe send a mail to 
> darktable-user+unsubscr...@lists.darktable.org 


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Fwd: Re: [darktable-user] Channel Mixer Oddity

[A. Huntley]

Nope...didn't work. I tried moving the mouse in/out a few times and even 
clicking on the entry field, but no go. What's additionally odd is if I 
right-click on the slider, the entry area has a blinking vertical bar 
for about 3 secs, and then it goes away! I haven't moved my mouse or 
anything. It definitely seems like a focus issue in that area. If it's a 
GTK3 issue, is this something the DT development team can even fix?


Regards,
Alan


 Forwarded Message 
Subject:Re: [darktable-user] Channel Mixer Oddity
Date:   Fri, 8 Jul 2016 20:54:28 +0300
From:   para...@paraf.in
CC: darktable-user@lists.darktable.org



It's probably the focus issue GTK3 is having on Mac platform, try moving 
the mouse into the popup area, out and then back again, then type. 
Haven't tried myself though.


On 08 Jul 2016, at 20:49, A. Huntley <alan.hunt...@cox.net 
<mailto:alan.hunt...@cox.net>> wrote:


Please excuse my ignorance on how to use these users lists...I think I 
sent an earlier reply directly to Tobias. Trying to send to list now! ;)


Tobias,

I'm running OS X 10.11.5 and DT 2.0.5

Thank you.

Regards,
Alan


 Forwarded Message 
Subject:    Re: [darktable-user] Channel Mixer Oddity
Date:   Fri, 08 Jul 2016 11:35:07 +0200
From:   Tobias Ellinghaus <m...@houz.org>
To: darktable-user@lists.darktable.org



On Donnerstag, 7. Juli 2016 11:27:54 CEST A. Huntley wrote:
> Hello All,

Hi.

> I'm trying to convert some files to B using the Channel Mixer and I'd
> like to enter specific values for R-G-B, as suggested in the User Manual
> for specific films. However, when I right-click to enter whatever value
> I need and see the blinking entry field (middle right side of the box)
> trying to enter, for example, .20 for the Red channel doesn't work. As
> soon as I hit period on my keyboard I'm tossed back into the lighttable.
> What am I doing wrong?

What window manager and what version of darktable are you using?

> Thank you for any help provided.
>
> Kind regards,
> AlanH

Tobias

 
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No virus found in this message.
Checked by AVG - www.avg.com <http://www.avg.com>
Version: 2016.0.7640 / Virus Database: 4613/12581 - Release Date: 07/08/16



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Re: [darktable-user] Channel Mixer Oddity

[Tobias Ellinghaus]

On Donnerstag, 7. Juli 2016 11:27:54 CEST A. Huntley wrote:
> Hello All,

Hi.

> I'm trying to convert some files to B using the Channel Mixer and I'd
> like to enter specific values for R-G-B, as suggested in the User Manual
> for specific films. However, when I right-click to enter whatever value
> I need and see the blinking entry field (middle right side of the box)
> trying to enter, for example, .20 for the Red channel doesn't work. As
> soon as I hit period on my keyboard I'm tossed back into the lighttable.
> What am I doing wrong?

What window manager and what version of darktable are you using?

> Thank you for any help provided.
> 
> Kind regards,
> AlanH

Tobias

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