Function: auto-image-file-mode

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
`image-file-name-regexps'. (fn &optional ARG)

Variable: auto-image-file-mode

Non-nil if Auto-Image-File mode is enabled.
See the command `auto-image-file-mode' for a description of this minor mode.
Setting this variable directly does not take effect;
either customize it (see the info node `Easy Customization')
or call the function `auto-image-file-mode'.