OpenImageIO?

[erichocean]

That's the industry-standard C++ library used to do this kind of stuff in the visual effects world. It supports a ton of image formats and a lot of different operations. It also doesn't require any external dependencies to be installed on the system (e.g. ImageMagick).

Anyway, thought I'd mention it since it exists and is of very high-quality.

[EyalAr]

Thanks @erichocean, looks interesting.