Using the ImageMagick backend seems to leak memory

[Tassilo Horn]

Hi all,

I just noticed that my emacs uses up more than a gigabyte memory.  It is
because of doc-view with ImageMagick backend.

After starting my emacs, it needs ~50 MB.  Firing up doc-view on a PDF
and showing page one increases to ~80 MB.  Switching to other pages
increases about 30 MB every time.  Switching to already seen pages
doesn't increase the memory requirements.  (I convert the docs with
doc-view-resolution set to 200, so 30 MB a page might be possible.)

Killing the buffer doesn't free the memory again, neither do
(clear-image-cache) or (garbage-collect).  So how do I reclaim that
memory?

Bye,
Tassilo