It's kinda strange that we still don't have a technology that would allow one to scan a magnetic medium at high resolution and then process it in software. This would be nice for all kinds of things that use magnetic tapes and platters — data recovery, perfect analog tape digitization, etc. The closest I've seen to it is that project that captures the raw signal from the video head of a VCR and then decodes it into a picture.
Isn't there a subset of that at least for floppy discs with Kryoflux or GreaseWeazle style controllers? They read the raw flux transitions off the drive head, and then it's up to software to figure out that it's a Commodore GCR disc or a Kaypro MFM one.
