Build OpenCV from souce

sudo apt-get install libgtk2.0-dev

I only encounter this problem. please google the error message you see to get the corresponding solutions

git clone https://github.com/Itseez/opencv.git

cd opencv

git checkout 2.4.6.2 -b 2.4.6.2

default is master branch and I manually checkout to 2.4.6.2 tag.
mkdir build(whatever name you want)

cd build

cmake-gui ..

(to generate the configurations you want and generate make file. sudo apt-get install cmake-gui if you don't have it.)

make; sudo mak install