I'd like to see Freeimage designed from upstream to allow compiling using external libraries (system png, jpeg, tiff, and so forth). This has been primariliy a concern for Gentoo. It has long been maintained for Gentoo by a gentleman who patches it heavily to use system libraries, but this sometimes causes conflicts by Freeimage attempting to use features that have been deprecated in newer versions of system libraries (as recently happened with Tiff 4.0). If you are interested, I'm sure the maintainer for Gentoo would be happy to assist you since he's been producing patches for Freeimage already, but it also means there is often a delay between a newrelease of Freeimage and it's availability to Gentoo.
Anonymous
I agree, this is important to all distros. System maintained libraries will be updated and supported for security patches and have been ported to many more architectures than is supported by freeimage. The patch is already written:
https://github.com/Sabayon/for-gentoo/blob/master/media-libs/freeimage/files/freeimage-3.15.4-unbundling.patch
it is very difficult to do long term release security maintenance on freeimage if all those libraries are included