Blender AgX in darktable (proof of concept)

[rvietor]

Well, if you are writing about it, I would certainly wait until there is a final version available to play with (final as in “included in the main darktable tree”, which I assume would mean the module is fixed except for minor tweaks).

Your quote from a few posts above from my post about the middle gray shows why:
since that post, the module has changed in very important ways, making my quoted post completely irrelevant for the current version… So if someone writes about the AgX module based on that information, the writing would be plain wrong.

(That’s not to say my comments were wrong at that time, just that the module changed a lot. And that’s what you can expect for a proof of concept, and the reason to discuss it here)

[EspE1]

Rest assured that nobody, at least not me, will write about AgX before it is completed. (The question was rather whether we could take a rest writing about some of the other stuff …)

[RawConvert (Andrew)]

@Patrick_Duquoc

On a lot of software, we have the possibility to act directly on the curve.

@kofa , would it theoretically be possible for the user to draw a curve a bit like RGB Curve and Tone Curve, and not have many sliders? So the process might be

• set white and black points much as now
• draw your curve
• adjust SOP and saturation
• tweak until happy

[kofa (István Kovács)]

@RawConvert

would it theoretically be possible for the user to draw a curve

It’s absolutely possible:

Blender AgX in darktable (proof of concept)

Just as an example – no agx was used here. This is the whole stack: [image] And this is a possible development (not trying to match the agx result): [image]

However, this particular parametric curve is a core part of the Blender AgX transform. So you can do it, even today, using the released version of damage. It’s not AgX, but it’s possible.

[Pascal_Obry]

@EspE1

It was my impression/hope that things had come so far that people may have started to form some thoughts in this direction.

It’s a bit early indeed, but yes I had some thought about this since I’m following this thread. My thinking at the moment is that AgX should be the default, but I have not yet tested it so everything is still possible.

If we go for AgX as default it should be done anyway after a full release cycle to get 6 months feedback on it’s usage.

[kofa (István Kovács)]

I’m considering the option that would allow you to bypass the curve. That would give you a pure log mapper without an additional module.

[RawConvert (Andrew)]

@kofa

It’s absolutely possible:

Just as an example – no agx was used here. This is the whole stack: [image] And this is a possible development (not trying to match the agx result): [image]

Maybe I wasn’t clear - I did mean drawing, but also using the AgX maths.

[kofa (István Kovács)]

I don’t know what you mean by ‘AgX maths’.
There are the primaries - available as a separate module. The curve, which you want to draw by hand. The log tone mapping: Blender AgX in darktable (proof of concept) - #1117 by kofa. And there’s nothing else.

[RawConvert (Andrew)]

AgX and your POC has an inset matrix, and a reversal of it afterwards, and if I understand ok, this maths is central to the results obtained. The module stack you linked to earlier couldn’t have had this processing. (Yes it did have primaries manipulation) That’s what I was getting at.

[Terry (Terry Pinfold)]

@Pascal_Obry

If we go for AgX as default it should be done anyway after a full release cycle to get 6 months feedback on it’s usage.

I 100% agree with this statement. It is definitely not a good idea to introduce a new module and make it the default at the same time. It has already taken a long time to make Sigmoid the default for DT 5.2.

I haven’t tried this module yet but I am excited to see it appear eventually in the weekly windows builds of 5.1 or 5.3 when it is ready for more general testing.

[kofa (István Kovács)]

@RawConvert

AgX and your POC has an inset matrix, and a reversal of it afterwards, and if I understand ok, this maths is central to the results obtained. The module stack you linked to earlier couldn’t have had this processing.

Insetting = reducing purity; reversal: increasing purity. Rotations can be reversed by using the opposite direction.

[RawConvert (Andrew)]

I hadn’t realised that. So Sigmoid and the Primaries module have been doing AgX things for some time. I’d got the idea AgX was all new to DT.

[kofa (István Kovács)]

The curve is different in sigmoid, but the primaries functionality is identical, yes. See here:

Introducing "primaries" feature for sigmoid

Introducing sigmoid’s “primaries” feature There’s a new feature of darktable’s sigmoid module in master. The initial work was done in this pull request where you can read all the relevant technical details. I thought it might be good to provide a more hands-on introduction at this point. However, some brief background information must be given first. The current code in master is a soft launch of sorts - none of the default settings are changed at this point, and your existing workflow, be it…

[Terry (Terry Pinfold)]

@kofa how far off is Agx from being included in the master? Could it be included and if it is not ready for 5.2 then be removed or is that too much stuffing around? It certainly sounds very promising work.

[kofa (István Kovács)]

I’ll raise a request once here we agree on what to keep, what to remove. I do not have plans to add more, except for some simple toggles (switching off the curve to get a simple log mapper; use the same primaries params for restoration – that’s more or less it).
If it ever gets to master, that will be after 5.2.

[Pascal_Obry]

@Terry

Could it be included and if it is not ready for 5.2 then be removed or is that too much stuffing around? It certainly sounds very promising work.

That cannot be done. If you remove a module then all edits done since it was introduced will be broken. So having it in the nightly build is not an option to me because to many people would be impacted without really knowing the possible revert if not following the thread here.

So the builds proposed here for the 3 platforms are OK for testing.

[Pascal_Obry]

One more point, the feature freeze for darktable 5.2 is mid-may. We are then very close, so either we are ready and a PR can be proposed early next week or this will have to wait for 5.4.

[kofa (István Kovács)]

OK, so we’ll return to the version with 2 tabs. Thanks everyone for the votes! I’m really happy not to be working ‘in an ivory tower’, and hope the module will make as many people happy as possible.

[priort (Todd Prior)]

@kofa

and hope the module will make as many people happy as possible.

I for one think it will. In my limited testing and using tools in DT the way I do, I am finding that in this module I can take the image almost to completion in many many cases …having then only to add some of the standard supporting modules and tweak noise and sharpening to taste…

[difrkaguilar (Franklin Aguilar Matos)]

I can only say that two months and one day ago was your first post related to this POC and the use of Blender’s AgX in darktable.

I can not be happier to see how it has evolved in these two months, thanks to you perseverance, the attention to details and help by testing and detecting bugs by users.

I hope that this module with its respective presets will be included definitively in the program, after passing the pertinent tests by the developers. You along with the other developers and content creators for darktable have my deepest admiration and respect, you make the program more and more addictive to use.

I thank you in advance to you and everyone involved in the process, from those who implement the versions for the different operating systems to those who give UI ideas and beta testers.