auto-image-file-mode is an interactive autoloaded compiled Lisp function in `image-file.el'.

(auto-image-file-mode &optional ARG)

Toggle visiting of image files as images (Auto Image File mode).
With a prefix argument ARG, enable Auto Image File mode if ARG is
positive, and disable it otherwise. If called from Lisp, enable
the mode if ARG is omitted or nil.

An image file is one whose name has an extension in
`image-file-name-extensions', or matches a regexp in