printing - How to restore as much detail as possible to a scanned image of an inkjet-printed page?

I have a photograph printed with an inkjet printer on a piece of paper. Unfortunately, I do not have access to the original file. Here's a small sample of what I'm stuck with:

Is there any way to make this image look less like a printed sheet of paper and more like an actual photograph? The horizontal bands from the printhead and the halftoning are quite obvious.

If possible, I'd prefer solutions that involve free software.