Gimp 3.0.0 Already Has A Killer Plugin -> GUI Batch Image Conversion And Editing (including with PDFs)
Gimp 3.0.0 Already Has A Killer Plugin -> GUI Batch Image Conversion And Editing (including with PDFs)
GitHub - kamilburda/batcher: Batch Processing Plug-in for GIMP 3
Throw this python plugin into your GIMP 3.0.0 installation's plugin folder (if you already have gimp installed, uninstall it and make a fresh install, at least that is my advice).
When you open GIMP under "File" is the "Batch Convert" option, which brings up a really nice GUI for doing conversion of image files, but also basic edits.
I know there are command line utilities for this kind of thing, I know there are paid commercial programs that do this kind of thing.. but having an open source optional-GUI utility that does this that also happens to be attached to an extremely mature and fully featured open source image editor is pretty awesome.