Both the raw and the higher level bindings should allow you to use any aspect of the original SDL2_image library. Please report an issue if you encounter a bug or feel that something is missing.
cabal install sdl2-image
For documentation, visit Hackage.
The original SDL2_image documentation can also help, as the bindings are close to a direct mapping.
A small example executable is included with the library. It loads and displays
a given image. You can find it in the example
directory.
cd sdl2-image
cabal run path/to/some/image.type