I only made it through the abstract but it looks like they’re matching the entire given LR image to a known entire HR image.

I’m saying with enough data you could potentially create a more predictive “magic sharpening” algorithm that didn’t strive to match a known original picture, but instead used that matching on divide & conquer subtiles of the original LR image against of a rainbow table of reduced HR tiles to predict a set of plausible HR images.

Basically if you can figure out with whatever context you have that the 4x4 brown smudge is very likely a brown cat, you can replace it with a brown cat. And if you know that, the orange/white/black smudge next to it is probably a calico, so stitch it in.

Of course the source image would have to be bigger than this, so it couldn’t be CSI-enhance icon to landscape, really more like a really good AI upscaler. You’d need a strong way to identify plausible scenes too. We can generate novel faces now, think this fuses the two concepts.