Basically just what the title says, I want to crop part of an image that has been imported as image plane.
you could just add some loop cuts and assign different materials to the unwanted parts or delete them.
activate correct face attributes in edit mode options if something distorts (screenshot upper right)
Or do it with shadernodes. something like this maybe:
You just need addon empty to image plane if i understand your question correctly
Could you illustrate what you’re trying to do?