I think the technique was used a lot prior in astronomy, where I encountered it the first time. There is called stacking, and the subpixel offset comes natural

I think the technique was used a lot prior in astronomy, where I encountered it the first time. There is called stacking, and the subpixel offset comes naturally from path distortion in the atmosphere itself. I remember using registax when the first batch of consumer telezoom point and click camera came out and got a 30x long exposure of the moon, with, well, mediocre results.