Last year we used SimpleCV (python) running on a ODROID-U2 with network tables from here:
https://github.com/robotpy/pynetworktables
So we could have it all Python and it worked fine.
The year before we did OpenCV in C++ using visual studio to compile an app on the driver station that interacted with the Java network tables on the driver side. We got great distances and it ran real fast except we ran c++ on the robot side and we could not get network tables that year working. We were going to convert the robot code to Java but ran out of time. The next year network tables worked great in c++ on the robot.
We played with the code that comes with the WPLIB this year and after adjusting the HSV setting we got decent distances with that. I am still thinking we might stick with off processing. Depends on how much we have to do in Autonomous and if we want it for other uses.