“This is not possible with a digital video signal, since again, there is no way to tell which pixel is more likely than another to contain detail rather than noise.”

If you have enough samples, you can statistically work out which pixels contain noise and which contain information, that is the basis of image stacking. The signal to noise ratio is lowered by the root of the number of images.

Or do you mean images originally captured on a digital camera, not digital scans of film based capture?

I feel that scanning multiple prints at high resolution, and then stacking them achieves the same thing, but I’m probably missing something in my understanding here.

I’d love to see a proof of concept from your work, I’m happy to provide you with some higher resolution images, something like 6000x4000 pixels should be enough to work with?

I’m all for any technique that might improve the image.