Writes an external image to a file.
graphics-ports
write-external-image external-image file &key if-exists
external-image
An external image.
file
A file.
if-exists
A keyword, defaulting to :error .
:error
The write-external-image function writes an external image to a file file .
write-external-image
if-exists is passed to open when opening file .
open
externalize-image