I've attached a patch against the mpl head in response to John's suggestion and helpful pointers on the users list. This adds a new function imsave to complement imread in the image module. I've also exposed it in the pyplot interface.
If this is presumptuous, feel free to remove it from the patch or ask me to remove it. This is my first contribution to matplotlib for a while and my first attempt at a patch like this.
Because I don't build matplotlib from source, I've done what testing I can without fully rebuilding matplotlib. I'd be reluctant to have this patch applied without someone else checking it first. It's pretty simple so applying it locally and running the demo file should be a good enough test.
image_py_patch.diff (5.95 KB)