Just run this...
Version 2:
curl https://gist.githubusercontent.com/k4zzk/24919a662faf35efc7ca96f39110ad5a/raw/0c934cab76da6ff966eb051f7a68ad0d529a9369/install-opencv-2.4.12.sh | sh
Version 3:
curl https://gist.githubusercontent.com/k4zzk/24919a662faf35efc7ca96f39110ad5a/raw/0c934cab76da6ff966eb051f7a68ad0d529a9369/install-opencv-3.1.0.sh | sh
Thenks!