VXL is a collection of computer vision libraries with contributions from Kitware, GE, Brown University, and others.
Folow the instructions at https://sourceforge.net/p/vxl/wiki/Git/
There are a few bugs affecting compilaiton, see 
- make -j9 is having a non-deterministic behavior - try running it a few times, but make -j5 sometimes works better as far as errors go. A plain make is always safer.
- If you find the error related to ffmpeg, then I just left all FFMPEG-related entries in CMAKE blank. That removes support for video loading but thats about it.
- A bug related to X11 means the headers from the wrong place are being used. I had to modify the cmake flag for x11 includes to point to /opt/local/include
- A bug related to OpenGL acceleration in vgui/tests means this test is outdated and should be ignored. Comment out that file or the offending lines. Alternatively, you could point the OpenGL CMake variables to /opt/... since those opengl libs contain the desired symbols, but they're older.
Writing a program that uses VXL
A simple example using CMake is hello-vxl:
Read the README.
Site oficial http://vxl.sourceforge.net/