You can use any image processing libraries you want as long as it is cross compilable.
Your problem will mostly be the lack of processing power, so everything depends on the resolution and processing you want to do. Some example are
Basically, everything that is using autoconf / automake is crosscompilable. There are some exceptions though. Package using CMake are usually less cross-compilation friendly.
If you are not comfortable with cross-compilation, I suggest you do it once with a simple library, and then to do it with tools like ptxdist or scratchbox