Removing noise is difficult if not impossible. The best someone could probably do is find a sensor whose noise characteristics are a superposition of their cameras and another additive distribution. There are simple ways to defeat this, but it's best not to share them, as I think the only people ruñning from this kind of tracking would be sketchy criminals.

> Removing noise is difficult if not impossible.

Completely removing noise is difficult-to-impossible. Attenuating the noise enough to impart a new noise pattern is much easier, though (not saying it's easy, just easier).

I did this sort of thing decades ago as part of larger system used for research.

That's effectively what I said :)

Removing is hard but not impossible: https://www.esenbil.com/photoclean