Set and use OpenCV in os X
1. Go find newly released OpenCV in http://opencv.org/downloads.html/, and download “OpenCV for Linux/Mac”, by now, the newest version is 2.4.6, unzip it. (By now, there is some bugs that lead to fail to use camera when using mac os and Linux, so you can download version 2.4.5 instead, until openCV fix these bugs…)