user32113: I use Linux for everything media production. I shoot RAW and process images with Darktable.
Now that I've started making videos too (4K ProRes), I need to apply a LUT to them in post. This requires importing a .cube file into Kdenlive. I know how to do that, but I don't know how to create a LUT.
Can I import a frame of video into Darktable, adjust the colors, and export a .cube file to import into Kdenlive to apply to the video?
Or are there other programs that will create a LUT on Linux? Can GIMP do it?
What Linux program can be used to create LUTs?

user40208: I was looking for that kind of software as well.
Then I found the .cube specification.
I thought to myself ... an average programmer should be able to do it in a couple of days ... and then I did the job ;-)
It's called lutcraft, a command line tool written in python3.
You can find it on github:
https://github.com/EinExperte/lutcraft
Instruction:


Create a neutral png image


lutc lut-neutral.png



Manipulate the colors of the image

Do pixel-level color adjustments as desired.
Tools I suggest are darktable, gimp, flowblade or cinelerra. Any other program doing pixel-level imaging will do fine.
Then save the image. I assume you call the file lut-x.png.

Convert the image into a lookup table (.cube file)


lutc -i lut-x.png lut-x.cube


This will output a 3D lookup tabble corresponding to the file lut-x.cube

If you have any questions / suggestions / etc., feel free to comment or e-mail me.

32113: <p>I use Linux for everything media production. I shoot RAW and process images with Darktable.</p>
<p>Now that I've started making videos too (4K ProRes), I need to apply a LUT to them in post. This requires importing a .cube file into Kdenlive. I know how to do that, but I don't know how to <em>create</em> a LUT.</p>
<p>Can I import a frame of video into Darktable, adjust the colors, and export a .cube file to import into Kdenlive to apply to the video?</p>
<p>Or are there other programs that will create a LUT on Linux? Can GIMP do it?</p>
<p><strong>What Linux program can be used to <em>create</em> LUTs?</strong></p>
 40208: <p>I was looking for that kind of software as well.
Then I found the .cube specification.</p>
<p>I thought to myself ... an average programmer should be able to do it in a couple of days ... and then I did the job ;-)</p>
<p>It's called <em><strong>lutcraft</strong></em>, a command line tool written in python3.</p>
<p>You can find it on github:</p>
<p><a href="https://github.com/EinExperte/lutcraft" rel="nofollow noreferrer">https://github.com/EinExperte/lutcraft</a></p>
<p>Instruction:</p>
<blockquote>
<ol>
<li>Create a neutral png image</li>
</ol>
</blockquote>
<pre><code>lutc lut-neutral.png
</code></pre>
<blockquote>
<ol start="2">
<li>Manipulate the colors of the image</li>
</ol>
<p>Do pixel-level color adjustments as desired.</p>
<p>Tools I suggest are darktable, gimp, flowblade or cinelerra. Any other program doing pixel-level imaging will do fine.</p>
<p>Then save the image. I assume you call the file lut-x.png.</p>
<ol start="3">
<li>Convert the image into a lookup table (.cube file)</li>
</ol>
</blockquote>
<pre><code>lutc -i lut-x.png lut-x.cube
</code></pre>
<blockquote>
<p>This will output a 3D lookup tabble corresponding to the file lut-x.cube</p>
</blockquote>
<p>If you have any questions / suggestions / etc., feel free to comment or e-mail me.</p>
