6.1.OpenCV Installation

OpenCV (Open Source Computer Vision) is a
library of programming functions mainly aimed at real-time computer vision. The library is cross-platform and free for use under the open-source BSD license.

This tutorial will tell how to install OpenCV 2.4.11.

Steps

1. Install Cmake and Python related package

Open Linux terminal and run ：

sudo apt-get -y install cmake
sudo apt-get -y install python-pygame python-scipy python-numpy
sudo apt-get -y install python-pip

2. Upgrade pip

sudo pip install --upgrade pip

3. Install virtual environment

sudo pip install virtualenvwrapper

4. Modify .bashrc file

vi ~/.bashrc

add :

source /usr/local/bin/virtualenvwrapper.sh

5. Reload .bashrc file

source ~/.bashrc

6. Create virtual environment

$ mkvirtualenv --system-site-packages env

7. Install dependencies：

sudo apt-get -y install libopencv-dev
sudo apt-get -y install build-essential checkinstall pkg-config yasm
sudo apt-get -y install libtiff4-dev libjpeg-dev libjasper-dev
sudo apt-get -y install libavcodec-dev libavformat-dev libswscale-dev libdc1394-22-dev libxine-dev libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev libv4l-dev
sudo apt-get -y install python-dev python-numpy
sudo apt-get -y install libtbb-dev
sudo apt-get -y install libqt4-dev libgtk2.0-dev
sudo apt-get -y install libfaac-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libtheora-dev libvorbis-dev libxvidcore-dev
sudo apt-get -y install x264 v4l-utils

8. Download OpenCV source code

wget -O OpenCV-2.4.11.zip  http://sourceforge.net/projects/opencvlibrary/fil...

9. Configure, compile and install

unzip OpenCV-2.4.11.zip 
cd opencv-2.4.11
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D INSTALL_C_EXAMPLES=ON -D INSTALL_PYTHON_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D WITH_OPENMP=ON .. 
make -j4  
sudo make install 
sudo sh -c 'echo "/usr/local/lib" > /etc/ld.so.conf.d/opencv.conf'
sudo ldconfig
sh -c 'echo "export PYTHONPATH=/usr/local/lib/python2.7/site-packages:\$PYTHONPATH"  >> ~/.bashrc'
source ~/.bashrc

10. Now the installation is done。
test

Download a face detection project from github to test the compiled OpenCV 。

git clone  https://github.com/shantnu/FaceDetect 
cd FaceDetect
python face_detect.py abba.png haarcascade_frontalface_default.xml

The detection result is showed in the following picture.

Reference
OpenCV installation stepsFace recognition with python