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 will never get those pixels back. They are gone. You can, however, create new pixels. They won’t be as good as the originals, but in some cases, they’ll be good enough. An open source AI/ML interpolation tool I have used with decent results is called Upscayl. There are AppImages, Flatpaks, and many Linux packages available to download.
I also found this: https://www.anyrec.io/image-upscaler/
It looks like it did a good job The windmill was less than 1/4 of the whole image.
And it seems to be free - but it will only handle a picture that is 300x300 px.
Sounds exactly what I want. Thanks I will check it out.
It seems Upscayl is cloud based, and as such has an ongoing cost… (Like everything today: Don’t sell the steak, sell the sizzle) What comes in these Appimages, Flatpacks and other packages you mentioned?