Variable: image-format-suffixes
image-format-suffixes is a variable defined in image.el.gz.
Value
((image/x-rgb "rgb") (image/x-icon "ico"))
Documentation
An alist associating image types with file name suffixes.
This is used as a hint by the ImageMagick library when detecting
the type of image data (that does not have an associated file name).
Each element has the form (MIME-CONTENT-TYPE EXTENSION).
If create-image is called with a :format attribute whose value
equals a content-type found in this list, the ImageMagick library is
told that the data would have the associated suffix if saved to a file.
Probably introduced at or before Emacs version 24.4.
Source Code
;; Defined in /usr/src/emacs/lisp/image.el.gz
(defvar image-format-suffixes
'((image/x-rgb "rgb") (image/x-icon "ico"))
"An alist associating image types with file name suffixes.
This is used as a hint by the ImageMagick library when detecting
the type of image data (that does not have an associated file name).
Each element has the form (MIME-CONTENT-TYPE EXTENSION).
If `create-image' is called with a :format attribute whose value
equals a content-type found in this list, the ImageMagick library is
told that the data would have the associated suffix if saved to a file.")