一、卸载opencv2.4.9： Going to the "build" folder directory of opencv from terminal, and execute the following：
1.$ sudo make uninstall
2.$ cd ..
3.$ sudo rm -r build
4.$ sudo rm -r /usr/local/include/opencv2 /usr/local/include/opencv /usr/include/opencv /usr/include/opencv2 /usr/local/share/opencv /usr/local/share/OpenCV /usr/share/opencv /usr/share/OpenCV /usr/local/bin/opencv* /usr/local/lib/libopencv*
这一步可能有error
下面执行如下操作：
5.sudo apt-get –purge remove opencv-doc opencv-data python-opencv
二、安装opencv
1.安装依赖项（opencv网页打开太慢，自己搜吧）、opencv网站（http://opencv.org/）、docs about opencv（http://docs.opencv.org/3.2.0/）
sudo apt-get install build-essential
sudo apt-get install cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
sudo apt-get install python-dev python-numpy libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-dev
2.下载opencv对应版本，如opencv3.2.3
cd ~/opencv-3.2.0-rc1
mkdir release
cd release
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..
make
sudo make install
3.安装完成后，写入opencv路径：sudo sh -c 'echo "usr/local/lib" > /etc/ld.so.conf.d/opencv.conf'
4.更新电脑配准