These color sliders look powerful and helpful. May I ask why they must be included in Agx, which continues to grow in power and UI complexity, and not integrated into the RGB Primaries module?
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AgX, as a transformation, consists of several steps.
- incoming ‘primaries transformation’ (same as in sigmoid)
- logarithmic tone mapping (sigmoid works differently)
- sigmoidal curve (like sigmoid, but the curve is different, and kind of ‘includes the log’, as I understand it)
- look controls (in sigmoid, ‘only’ hue preservation)
- linearisation (‘inverse gamma’) (in sigmoid, ‘included in curve’)
- outgoing ‘primaries transformation’ (like sigmoid, there the rotations are automatically undone, and only the attenuation can be set)
Sure, it could be split. You already have the primaries module, you can sandwich any curve and any tools between two instances to inset/rotate and outset/unrotate; you can achieve linearisation using a carefully crafted tone / RGB curve. The only thing darktable does not have ‘stand alone’, is the logarithmic tone mapping.
However, it would be impossible to provide a single ‘Blender-like’ preset, for example. You’d have a primaries instance with ‘Blender-like in’ preset, then a log tone mapping with a ‘Blender-like’ preset, then a jedsmithsigmoid with a ‘Blender-like’ preset (and people would ask 'why did you have to add another ‘sigmoid’, what’s the difference), (we’ll skip the look), then a ‘power’ module to apply the ‘inverse gamma’, again with a ‘Blender-like’ preset (or an rgb curve instance with a preset like ‘power 2.2’), then another instance of primaries with ‘Blender like out’ preset. Would you really like to orchestrate that?
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Just as an example – no agx was used here. This is the whole stack:
And this is a possible development (not trying to match the agx result):
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I don’t remember, I may have posted this before: we think about and the curve in agx and filmic as an S curve (this already has the power(2.2) linearisation included, so shows linear light output) :
However, here the x-axis is logarithmic. Switching it to linear:
This is the curve from -10 EV to + 6.5 EV around mid-grey. Mid-grey itself is the dashed vertical line, which intersects the red ‘S-curve’ of AgX at (x, y) = (0.18, 0.18).
You can compare the curve with the rgb curve in the screenshot in the previous post:
What do you mean darktable doesn’t have display mapping transformations ? I’m following this thread all along and this got me really confused
One can already choose between the base curve, filmic and sigmoid. AgX will be yet another option.
(I hope I understood your question correctly.)
I don’t think I ever said or implied that.
Ah. I meant the output-specific transformations that are part of AgX in Blender, to manage out-of-gamut colours.
The ones implemented in AgXBaseP3.py and AgXBasesRGB.py:
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Oh okay got it
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Hmm, this is really strange. Notice that agx is not active, so it’s not something I broke. Debug vs release build.
Edit: never mind:
Probably this caused the confusion the other day, too.
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My photo assignment yesterday was a real challenge.
A perfect opportunity to test the usability of AgX:
Here are these three examples if you want to play yourself:
This files are licensed Creative Commons, By-Attribution, Share-Alike.
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If you are looking for help/feedback, please post your xmp sidecars. And please post smaller images, e.g. no larger than 2000x2000 px, JPG quality no higher than 90%.
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Is the issue that you discovered a bug in the agx current proof of concept?
sorry no problem with agx but some with my english
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some people here use Deepl to translate their posts into english DeepL Translate: The world's most accurate translator
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Hello,
Here are the results of my tests. I started playing with primaries by using a color chart and a few photos to create two basic presets for processing the following examples.
agx_1 Portrait RGB.dtpreset (1.2 KB)
agx_2 base RGB (vs Blender Like).dtpreset (1.2 KB)
1 Portrait preset
The other examples will be in the next post
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2 Base preset (I started with the Blender like preset)
And here’s the blue tavern with the two presets
I hope this helps the project along, and I welcome any criticism.
Greetings,
Christian
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