Invisible watermark — a stamp you can't see

A tiny ‘number stamp’ placed inside a photo, video or music file, one people can't see. It is designed so a trace of the stamp survives even when Instagram compresses the file.

Experimental · not for legal attribution

Watermark tiers T1–T7 were not remeasured on 2026-10-17. The public watermark column stays pending verification, including the existing limit that a 5° rotation is a weak case.

Plain words · exact workings

An invisible stamp (invisible watermark)

A technique that hides a tiny ‘secret stamp’ inside a photo, video or song, too small for people to see.

The simple story

Writing ‘mine’ on a friend’s picture would spoil it. So instead of writing anything, we change the colours just a tiny bit.
People see no difference, but a computer gathers those small changes and reads a number such as ‘XENLOOK-42’.
A well-made stamp is designed to leave a trace even when Instagram shrinks the photo.

How it works, exactly

Add a very small change ε to the original signal (pixels or waveform). What you see ≈ original + ε.
More ε goes into textured areas (clothes, leaves) than into flat sky, where the eye is less sensitive.
The detector collects the ε pattern across many cells and recovers the message. (Meta VideoSeal/AudioSeal family)
Watermark = an ID planted inside the file. Use it later to find who made something from the file alone.

Easy to mix up

It is not a visible logo or see-through text (a visible watermark).
It is not a fingerprint either. A fingerprint plants nothing; it only computes a ‘look number’.

In the demo below, compare original / ε(+1) / ε ×40 amplified. The same to the eye, different to the machine.

Demo · see it for yourself

Samples you can try

Play photos, video, music and documents, take their fingerprint number, and check their Content Credentials (C2PA). XenLook holds thousands of character media files; these few samples were picked to show the idea and the check simply.

The invisible stamp

Left and middle look the same to the eye. Right is a magnifier that blows ε up 40×.

what you see ≈ original + ε

Real VideoSeal encoding uses a smarter pattern. This is a lesson in why it stays invisible.

1 Watermark

What XenLook does

Right after generation, as step 1, the MIT-licensed Meta VideoSeal (images, video) and AudioSeal (music) engines embed a soft binding. The forensic mark, fingerprint, C2PA and NFT follow.

Open source we use (commercial use OK)

VideoSeal / AudioSeal — MIT. TrustMark and non-commercial research models are left out of the fleet default.

VideoSeal (MIT) GitHub

XMSE status (this step)

Item	Status	Note
OSS choice · catalog	Applied	MIT confirmed
VideoSeal MIT	Applied	DGX image encode PASS
Pipeline hook	Applied	pre-sign 10 surfaces + portal API
C2PA link	Ready	soft stage before signing
Required on every output	In progress	widening entrypoints

Demo studio → Full XMSE stack NFT and blockchain status C2PA generator →