How to create a LUT from a reference image, in your browser, for free

Updated 2026-09-24 · 7 min read · by Nunik Co.

You have a still that looks the way you want your footage to look. This is how to turn that into a LUT you can drop on a whole timeline, without Photoshop, without a plugin, and without sending a single frame to a server.

Why two frames, not one

Most "LUT from image" tools take a single reference and hand you a LUT. That LUT knows what the destination looks like but has no idea what your footage looks like to begin with, so it applies the same push to every camera and every exposure and hopes.

ChromaMimic takes two frames: your original (the ungraded still from your footage) and the reference (the look you want). It measures the colour distribution of both and learns the transform between them. The .cube it writes is specific to your camera's starting point, which is the difference between a LUT that lands and a LUT you spend an hour fixing.

Step 1: pick the right frames

• Original: export a still from your footage as a JPG or PNG. Choose a frame that represents the shot: a face if there are faces, the dominant colours of the scene, a normal exposure.
• Reference: a film frame, a graded still, a photo. Anything you can screenshot. Higher resolution helps but is not essential; the distribution is what matters.
• Match the content. A daytime exterior original and a night interior reference will produce a LUT that fights itself. Similar lighting, similar subject, similar exposure gives a clean match.
• Convert log first. If your footage is S-Log3, V-Log, C-Log or any other log profile, apply the colour space transform in your editor before you export the original still. Here is why that matters.

Step 2: load them

Open ChromaMimic. Drop the original on the left and the reference on the right. Nothing happens on a server at this point or any other: the whole engine runs in your browser tab. You can turn your wifi off and it keeps working.

Step 3: build

Press Build. ChromaMimic runs three colour science methods and blends them: Reinhard transfer (matches the mean and spread of each channel in LAB), per channel histogram matching (matches the full tonal distribution), and optimal transport (moves colour mass from one distribution to the other with the least total change). The result is a transform that pushes your original towards the reference.

Drag the before and after handle across the preview. If it is close, move on. If it is too strong, lower the strength slider. If it has artefacts in flat areas, raise smoothing. If the blacks look lifted, turn on black and white normalisation, which pins true black and true white so the grade does not go milky.

Step 4: refine

The grade controls (temperature, tint, exposure, contrast, saturation, vibrance, shadows, highlights, fade) let you adjust the match before you export. This is where you take a 90 percent match to 100. The adjustments are baked into the .cube, so what you see in the preview is what your editor will apply.

Step 5: export

Download the .cube. The default size is 33, which every current editor accepts. 17 is smaller and faster to build. 65 is highest precision but some older Premiere Pro builds reject it, so if a 65 LUT will not load, rebuild at 33.

You can also export a .png of the graded still, an .xmp preset for Lightroom and Camera Raw, and a 16 bit .dng of the graded frame. What each of those is for.

Step 6: apply it

• DaVinci Resolve: put the .cube in the LUT folder (Project Settings, Color Management, Open LUT Folder), press Update Lists, then right click a node and choose it under 3D LUT. Folder locations and the "not showing up" fixes.
• Premiere Pro: Lumetri Color, Creative, Look, Browse to the file. If it will not load.
• Final Cut Pro: drag the Custom LUT effect onto the clip and choose the file. The Camera LUT versus Custom LUT distinction.

What a matched LUT can and cannot do

A LUT is a global colour transform. It changes every pixel by its colour value and nothing else. It cannot add the lens, the lighting, the grain, the diffusion or the composition that made the reference look the way it does. It will get the palette and the tonal shape, which is most of the feeling, and it will get them consistently across every clip you apply it to.

For a look that needs per shot work, a matched LUT is the starting grade, not the finished one. That is honest, and it is also how professional colourists use LUTs.