About LUT Generator

LUT Generator is a colour engine with a web interface. You bring a photo, or a frame from an SDR video, plus a reference image you like. It measures both, fits a single global colour transform, shows you the result, and writes that transform into a standard .cube file your editor can load.

How the reference match works

Images are decoded to sRGB and summarised as mean and standard deviation in CIE Lab, computed on a D65 white point. Extreme samples are winsorised first so one clipped highlight cannot drag the whole curve. The source statistics are then mapped onto the reference statistics with a per-channel affine transform whose scale factor is clamped between 0.67 and 1.5. Everything you see afterwards — preview, PNG, and the exported table — is a resampling of that one continuous function.

A single reference image cannot tell you the LUT that produced it. A photograph has already lost the decisions that made it: the curve, the white balance, the second grade and the shot it was pulled from. What this tool produces is a reusable style approximation.

What it exports

  • A 3D .cube table at 33 or 65 points, with R varying fastest, then G, then B.
  • A header that names the working space: either sRGB → sRGB for photos, or Rec.709 primaries with a pure Gamma 2.4 creative look for already-normalised SDR video.
  • A PNG of the current frame rendered from the same parsed table, with alpha preserved.

The exported file is round-tripped through the CUBE text and re-parsed before anything is shown or downloaded, so a table that cannot be read back is never presented as working.

What it does not do

  • No camera Log, HLG or PQ conversion, and no HDR output.
  • No rendered video, and no frame-interpolation or relighting.
  • No masks, face detection or skin protection. It is a global transform, so it treats skin exactly like every other pixel.
  • No film grain or vignette. Those are spatial effects that a 3D colour LUT cannot represent.
  • No RAW or HEIC decoding, no format converter, and no 1D .cube support.

Where your files go

Matching, fine-tuning and PNG previews run locally. A custom workbench .cube export sends its generated color table to the server for validation and credit accounting, without uploading the source image. When you send an AI request, reduced source and optional reference previews go to OpenRouter with your parameters and text. Original files and EXIF are not included. Account and credit records persist separately from the temporary workbench state.

Editor compatibility

Export a standard .cube file, then check your editor’s import and color-management settings. The editor names below are workflow references, not a claim that every version has been tested here.

  • DaVinci Resolve
  • Premiere Pro
  • Final Cut Pro
  • After Effects
  • Filmora
  • CapCut Desktop
  • Avid Media Composer

This is a preview

Local matching and PNG downloads are free. Custom workbench LUT exports and AI requests use credits, with five welcome credits for a new account. Google sign-in still needs configuration and real payments are not enabled. You can already try local matching in the workbench.