inline images in org-mode

[Robert Goldman <rpgoldman@sift.info>]

I was looking for a way to put illustrations in my org-mode files so
that I could actually look at them while editing the org stuff.  I found
a post a while ago suggesting using iimage mode (which is included with
the Aquamacs that I use, and is readily available if you don't have it
with your emacs).

I found I needed to do a little customization to make iimage work for
me, so I thought I would post the details in case they were useful to
anyone else.

Here's the bit I added to my org configuration to make this work:

(add-hook 'org-mode-hook
          '(lambda ()
            ;; unnecessary
            ;; (make-variable-buffer-local
'iimage-mode-image-filename-regex)
            (let ((file-extension-regex
                   (regexp-opt (nconc (mapcar #'upcase
                                              image-file-name-extensions)
                                      image-file-name-extensions)
                               t)))
              (setq iimage-mode-image-regex-alist
                    (list
                     (cons
                      (concat
                       "\\[\\["
                       (regexp-quote "file:")
                       "\\([^]]+\." file-extension-regex "\\)"
                       "\\]"
                       "\\(\\[" "\\([^]]+\\)" "\\]\\)?"
                       "\\]")
                      1))))))

Note that this /only/ displays inline local (file) links, not http
images.  It wouldn't be hard to add that --- I built the above by
copying and modifying the org-bracket-link-analytic-regexp variable
initialization.  If one wanted to put this more generally into org-mode,
it would probably be right to make the iimage-mode-image-regex-alist be
under control of some org customization (to handle local versus all
images, etc.).

I don't generally want iimage mode on in all of my org-mode buffers, so
I use the file variables block to engage iimage mode where I want it.
If you'd like it always to be on, then you can just add iimage-mode
(it's a minor mode) to your org-mode-hook.

Hope that's of interest to someone...

Cheers,
r