The Win32 API offers very limited image conversion. There are many third party libraries, some free, others not. I'm currently looking at CxImage to replace Leadtools, which is now even more expensive than before and isn't royalty free. If you are willing to pay more, one royalty free library I've used is http://www.gdpicture.com/[^]. The ActiveX part always annoyed me, but it had a good PDF viewer component, so I lived with it. I'm also going to evaluate http://www.data-tech.com/products/imaging/imageman-dll.aspx[^]. (I work for none of these companies.)
If you are interested in audio development, I made a simple SDK to tag audio libraries patches. There is ton of things people are waiting for on this topic:
- analyze a WAV file and extract tagging informations (Percussive, Smooth ...)
- extract informations from REX files and convert them in tags
Plug-ins can be .NET assemblies or native DLL
as Universal Patch Finder is free,
the idea is to let all of this entirely free.