darkflag / cluttool

cluttool - create and convert 3D/color LUTs

cluttool - create and convert 3D/color LUTs

This tool is a sort of swiss army knife for color LUTs. Color LUTs concisely describe linear color transformations that many video monitors and post production software can understand. There are a relatively small number of color LUT file formats, such as 3D LUT (3DL), Cube LUT, and Hald CLUT, but no one LUT format is used by every software and firmware system. This tool may help you to convert between LUT formats, or generate new ones in the format that you need.

Not all LUTs are created equal

This tool is not aware of the context of the color LUT. It doesn't know what type of source medium it was made for, nor what its goals are. It simply converts the color transformations verbatim.

Those film simulation HaldCLUT files aren't going to apply correctly to s-log footage, and those video style LUT packs aren't going to apply corrrectly to your 8-bit gamma or 14-bit RAW photos. If you're grabbing color LUTs off the internet, you should understand what source the color LUT was created for, and what kind of transformation it does.

When in doubt, just test it. However, some LUT packs are purchased and non-refundable. My hope is that this tool will help make it easier for you to freely create your own color LUTs for your own needs.

Supported color LUT formats:

Source format	Destination format	Supported?
Hald CLUT (.png)	3D LUT (.3dl)	Yes
Hald CLUT (.png)	Cube LUT (.cube)	Yes
3D LUT (.3dl)	Hald CLUT (.png)	No
3D LUT (.3dl)	Cube LUT (.cube)	No
Cube LUT (.cube)	Hald CLUT (.png)	No
Cube LUT (.cube)	3D LUT (.3dl)	No

I built the framework to support all possible conversions, but I personally only needed to convert from Hald CLUT (.png) to cube and 3dl, so that is all I implemented. The places in the code marked raise NotImplementedError() indicate where there is missing logic for the unimplemented conversions.

Similar Tools

3DLutConverter is another color LUT converter with similar goals:

https://github.com/spoilt-exile/3DLutConverter

However, it only supports...(TODO)

References:

• Hald CLUT reference: http://www.quelsolaar.com/technology/clut.html
• 3D LUT (3DL) reference: http://download.autodesk.com/us/systemdocs/pdf/lustre_color_management_user_guide.pdf#page=14
• Cube LUT reference: http://wwwimages.adobe.com/www.adobe.com/content/dam/acom/en/products/speedgrade/cc/pdfs/cube-lut-specification-1.0.pdf