Too few pixels: the most fixable kind
A small photo looks soft because it is stretched on a bigger screen or print. The edges are still there, just spread over too few pixels. This is the case an AI restoration model handles best, because it can rebuild plausible edges and texture at 2x or 4x while it enlarges the picture.
Check the original dimensions before you start. If the photo is a few hundred pixels wide, plan for 4x only when you need the size, and judge the result at the size you will use. A photo that already has plenty of pixels and still looks soft is probably a focus problem instead.
- Look up the pixel width and height of the original
- Choose 2x first, 4x only when the destination needs it
- Judge the result at the size you will actually use

