Some of the photos I take, to get the subject large enough in the frame I have to use electronic zoom. I don’t have money for a nice zoom lens. I tried using an adapter for one of Dad’s zoom lenses but it sometimes gives me issues. So I use a 4x zoom - which basically cuts off 3/4 of my sensor then expands the picture to full size (I guess by some sort of averaging math to create the discarded pixels)
Is there anything I can do in post to get some of that resolution back - even if it made up. I am a Linux user, so a workflow in GIMP would be great, or any other Free/Libre software you might suggest?
You can do super resolution in post if you take multiple photos of a still subject. They do this in astrophotography.