OpenCV on PI2 is achievable. You ain't gonna get there with Arduino Amtel microprocessors. PI2 is a full environment and wee little quad-core + GPU power house

OpenCV on PI2 is achievable. You ain't gonna get there with Arduino Amtel microprocessors. PI2 is a full environment and wee little quad-core + GPU power house and not too bad for programming especially with wiringPI, but Arduino is simpler and much more practical to learn stuff on. You can get kids in primary school doing Arduino which is not really going to happen easily with PI. Both are pretty cheap, but Arduino is cheaper.