[O] proposed modification of org-display-inline-images

[John Kitchin]

I would like to propose a change to org-display-inline-images so it can
rescale images even if imagemagick is not built in to emacs. There is
currently no way to rescale images when they are displayed in that case
AFAICS. This is particularly a problem on Windows, as we have never
found a binary linked to imagemagick for that platform.

I propose we define a new customizable variable called something like
org-inline-image-resize-function, and a function that takes a filename
and the resize options, and returns a path to a resized function (in the
temporary directory). The variable isn't technically necessary, but if
someone wanted to use an alternative function, it would enable it.

This function would use the "convert" program from imagemagick to do the
resizing.  This program can be installed independently on all the
platforms I think.

Since this is just for display in org, I suggest that we use a syntax like:

#+attr_org: :resize resize-options
[[./file.png]]

the resize-options could be anything here:
http://www.imagemagick.org/script/command-line-processing.php#geometry

It would enable things like:

reduce size by 50%
#+attr_org: :resize 50%

set width to 300, preserving aspect ratio
#+attr_org: :resize 300

set height to 200, and preserve aspect ratio
#+attr_org: :resize x200

set size to 200x300 and change aspect ratio
#+attr_org: :resize 200x300!

Any thoughts on this proposal?

-- 
Professor John Kitchin
Doherty Hall A207F
Department of Chemical Engineering
Carnegie Mellon University
Pittsburgh, PA 15213
412-268-7803
@johnkitchin
http://kitchingroup.cheme.cmu.edu