Can I import an image to use for annotations or a signature in the macOS Preview app? I use the Preview app (within macOS) and I'd love to add a traditional stamp to some documents.  I note that under Tools > Annotate > Signature > Manage Signatures... I can use either the trackpad or camera to add signatures.

Is there a way to import pictures (or even better, vectors) to my signatures without using the trackpad/camera?
I don't think there's any other way than just printing the photo out and then add it with the camera.