Skip to content

LUT Export

Turns a colour grade built in ComfyUI into a portable .cube file. Take your look to other apps, or load it back with LUT Import.

LUT Export — before / after
In ComfyUI Add Node → ComfyUI-JH-PixelPro → color → LUT Export (.cube)
Good for Reusing a grade on many photos, sharing a look, matching video and stills

When to use it

You have a grade you like, built from several ComfyUI colour nodes. A LUT freezes that grade into one small file. You can then apply it quickly, over and over, or open it in other software.

The LUT workflow

  1. HALD Identity makes a neutral colour chart.
  2. Colour nodes grade the chart, for example Tone Curve. Use colour-only nodes: no blur, sharpen, resize or crop.
  3. LUT Export reads the graded chart and writes a .cube file to ComfyUI's output/ folder.
  4. Use the .cube file:
    • In ComfyUI with LUT Import, on any photo, optionally through a mask.
    • In other apps that read Adobe Cube 1.0 files. The project's release notes list DaVinci Resolve, Premiere Pro, OBS Studio and OCIO. Photoshop can load .cube files too, through a Color Lookup adjustment layer.

Check the file in your target app before relying on it. This pack writes and reads the standard format, and has no OCIO or Photoshop integration of its own.

Quick start

  1. Add HALD Identity (level 8).
  2. Connect its image to a colour node, such as Tone Curve, and set the grade.
  3. Add LUT Export. Connect the graded image to image and HALD Identity's level output to level.
  4. Set filename (for example my_look.cube) and title, then queue the prompt.
  5. Find the file in ComfyUI/output/. The node's path output shows where it was written.

Settings

Setting Default What it does Tip
image — The graded HALD chart. Must be the full chart, same size as it left HALD Identity.
level 8 (range 2 to 16) HALD level of the chart. Must match HALD Identity; wire the two together.
filename pack_lut.cube Output name. Relative names go to ComfyUI's output/ folder; absolute paths are used as given. .cube is added if missing. An existing file with the same name is overwritten. Pick a new name per look.
title JHPixelPro LUT Name stored inside the file, shown by LUT browsers. Use a descriptive name such as Warm Portrait v2.

Output: path — the full path of the written .cube file.

Tips from retouching

  • Keep the chain colour-only. If the LUT looks wrong in another app, a spatial node (blur, sharpen, resize) between HALD and Export is the usual cause.
  • A LUT can only store colour changes that depend on each pixel's own colour. Local edits such as masks, dodge and burn, or skin smoothing cannot be baked in.
  • Level 8 is plenty for creative looks. Go higher only for very steep curves.
  • The output folder must exist. Missing parent folders for an absolute path raise an error.
  • Test the new file straight away: LUT Import on a photo, with strength 1.0.
Under the hood

The chart must be exactly L³ × L³ pixels for the given level and contain only finite values, otherwise the node raises an error. Values are clamped to [0, 1]. The file has the headers TITLE, LUT_3D_SIZE (L²), DOMAIN_MIN 0 0 0 and DOMAIN_MAX 1 1 1, followed by N³ lines (N = L²) of r g b with six decimals, red changing fastest, then green, then blue. Lines end with LF. Only the first image of a batch is exported. The write is plain file I/O, so there is nothing to speed up on a GPU.

Example workflow

LUT Export example workflow. HALD Identity makes a neutral chart, Tone Curve grades it, and LUT Export writes pixelpro_demo.cube to ComfyUI/output/; a Preview Any node shows the file path. No input image is needed. Open LUT Import to apply the file.

Result: LUT Export example workflow