compile opencv in centos

(1) 源
cat /etc/centos-release
sudo yum -y update
yum list available opencv*

（2）工具
sudo yum groupinstall ‘Development Tools’
sudo yum install cmake git pkgconfig

（3）一些依赖
sudo yum install libpng-devel libjpeg-turbo-devel jasper-devel openexr-devel libtiff-devel libwebp-devel

sudo yum install libdc1394-devel libv4l-devel gstreamer-plugins-base-devel
sudo yum install gtk2-devel

（4）
sudo yum install tbb-devel eigen3-devel

（5）python pip
$ curl “https://bootstrap.pypa.io/get-pip.py” -o “get-pip.py”
$ sudo python get-pip.py

（6）python分割环境
$sudo pip install virtualenv virtualenvwrapper$ sudo rm -rf ~/.cache/pip

~/.bashrc by adding these two lines to the file.
$export WORKON_HOME=$HOME/.virtualenvs
$ source /usr/bin/virtualenvwrapper.sh

（7） 虚拟环境
Now is the time to create a virtual environment, let’s call it cv

$ mkvirtualenv cv

You will notice a (cv) indicator at your command line. It means that we are in the virtual environment where we will be installing OpenCV. You can exit this environment by typing

$ deactivate

if you are not in the cv virtual environment, just type in

$ workon cv

（8）python环境
$ python –version

and you should see Python 2.7 version.
Install Python 2.7 development tools

$ sudo yum install python-devel

Install NumPy since OpenCV is using its arrays (and it is a very powerful package as well)

$ sudo pip install numpy

（9）install opencv
$cd ~$ git clone https://github.com/Itseez/opencv.git
$cd opencv$ git checkout 3.1.0

$cd ~$ git clone https://github.com/Itseez/opencv_contrib.git
$cd opencv_contrib$ git checkout 3.1.0

$cd ~/opencv$ mkdir build
$ cd build

$cmake -D CMAKE_BUILD_TYPE=RELEASE \ -D CMAKE_INSTALL_PREFIX=/usr/local \ -D OPENCV_EXTRA_MODULES_PATH=~/opencv_contrib/modules \ -D INSTALL_C_EXAMPLES=OFF \ -D INSTALL_PYTHON_EXAMPLES=ON \ -D BUILD_EXAMPLES=ON \ -D BUILD_OPENCV_PYTHON2=ON ..$ sudo make
$sudo make install$ sudo ldconfig

Check the following folder and see if OpenCV is installed

/usr/local/lib/python2.7/site-packages

（10) 虚拟环境安装
Now is the time to create a symbolic link to OpenCV library into the site-packages directory of the cv virtual environment:

$cd ~/.virtualenvs/cv/lib/python2.7/site-packages/$ ln -s /usr/local/lib/python2.7/site-packages/cv2.so cv2.so
Your installation is successfuly completed. You can confirm it by going into the virtual environment and importing OpenCV library.

$workon cv$ python

import cv2
cv2.version
3.1.0’