As Arc mentioned the yesterday, GTK+ is well on its way to getting a native Win32 GDI+-based image loader, using Microsoft's so-called GDI+ "flat" API. We've avoided any hard run-time or compile-time dependencies as we're looking up GDI+'s functions at run-time from the DLL. In theory, this should let us do away with our libpng/libjpeg/libtiff dependencies on Win32 and let us support precisely whatever image formats Win32 natively supports.
Today, I managed to get single-frame images working properly, including scaling them (which most of the built-in GdkPixbuf loader plugins don't get right, FWIW). What's left is:
- Importing metadata (orientation, PNG text chunks, etc.)
- Handling animations (i.e. multi-frame GIFs)
- Saving pixbufs to PNGs/JPEGs/whatever
Unfortunately, this won't ever have progressive loading, since I don't believe that GDI+ supports that.
Anyone who's interested in checking it out and contributing, the code is in GNOME's SVN, under the gdpi-pixbuf-loader module.