how to rotate image files of GENERIC angles?

[Jeffrey Walton]

On Sat, Nov 19, 2022 at 9:36 AM Marco Fioretti <mfioretti at nexaima.net> wrote:
>
> I am scanning lots of A4 sheets with 6/7 small photographs glued on each side. The problem is that most of those photographs, were deliberately NOT glued parallel to the sheet edges, and often each at a different angle
>
> So to get images that display well on screen I should crop every image, ROTATE it so that the bottom side is "horizontal", and then crop it again.
>
> The problem is the rotation. I Have searched before posting, but only found tools like jpegtran that only rotate of multiple of 90 degrees.
>
> What I would need, instead, is any Linux-compatible tool to which I can say "rotate this file N degrees", for every N integer between (at least) 0 and 90.
>
> Suggestions? CLI or GUI is the same, albeit I'd prefer a command line solution.

Gimp works for me in situations where I need to square up a photo.
However, my use case is usually a one-off with a single scanned image.
I don't usually need to do it hundreds of times.

Also see https://docs.gimp.org/en/gimp-layer-rotate-arbitrary.html .

Jeff