Based on https://www.pyimagesearch.com/2016/10/24/ubuntu-16-04-how-to-install-opencv/
############## Version 3.4.0 ##################
1. [前提]
conda environment
python = 3.5
CUDA = 9.0
gcc/g++ = 6.0
2. [conda 环境设置]
将下一行添加到 ~/.bashrc，
```
export PATH=/path-to-your-anaconda/bin:$PATH
```
添加后source该文件
```
source ~/.bashrc
```
生成python 3.5环境
```
conda create -n py35 python=3.5
```
3. [路径设置]
# 在激活py35环境的同时激活以下路径设置
```
mkdir -p /home/virtual-environments/anaconda2/envs/py35/etc/conda/activate.d
touch /home/virtual-environments/anaconda2/envs/py35/etc/conda/activate.d/activate.sh
nano /home/virtual-environments/anaconda2/envs/py35/etc/conda/activate.d/activate.sh
```
----- 将下面的内容写入activate.sh-----
```
#!/bin/sh
ORIGINAL_LD_LIBRARY=$LD_LIBRARY_PATH
ORIGINAL_PATH=$PATH
ORIGINAL_PKG_CONFIG_PATH=$PKG_CONFIG_PATH
ORIGINAL_PYTHONPATH=$PYTHONPATH
ORIGINAL_CPATH=$CPATH
export LD_LIBRARY_PATH=/home/virtual-environments/anaconda2/lib:/usr/local/cuda$
export PATH=/usr/local/cuda-9.0/bin:$PATH
export PKG_CONFIG_PATH=/home/virtual-environments/anaconda2/lib/pkgconfig:/usr/$
export PYTHONPATH=/home/virtual-environments/anaconda2/envs/py35/bin/python3:$P$
export CPATH=/home/virtual-environments/anaconda2/envs/py35/include:$CPATH
```
---------------我是分割线--------------
# 在解除py35环境同时解除路径设置
```
chmod +x /home/virtual-environments/anaconda2/envs/py35/etc/conda/activate.d/activate.sh
mkdir -p /home/virtual-environments/anaconda2/envs/py35/etc/conda/deactivate.d
touch /home/virtual-environments/anaconda2/envs/py35/etc/conda/deactivate.d/deactivate.sh
nano /home/virtual-environments/anaconda2/envs/py35/etc/conda/deactivate.d/deactivate.sh
```
----- 将下面的内容写入 deactivate.sh -----
```
#!/bin/sh
export LD_LIBRARY_PATH=$ORIGINAL_LD_LIBRARY_PATH
export PATH=$ORIGINAL_PATH
export PKG_CONFIG_PATH=$ORIGINAL_PKG_CONFIG_PATH
export PYTHONPATH=$ORIGINAL_PYTHONPATH
export CPATH=$ORIGINAL_CPATH
unset ORIGINAL_LD_LIBRARY_PATH
unset ORIGINAL_PATH
unset ORIGINAL_PKG_CONFIG_PATH
unset ORIGINAL_PYTHONPATH
unset ORIGINAL_CPATH
```
--------------- 我是分割线 --------------
# chmod一下deactivate.sh
```
chmod +x /path-to-your-anaconda/envs/py35/etc/conda/deactivate.d/deactivate.sh
```
4. [安装OpenCV依赖库们]
```
source activate py35
conda install -n py35 numpy
conda install -n py35 -c conda-forge libzip
conda install -n py35 -c anaconda cmake
conda install -n py35 -c anaconda libboost
conda install -n py35 -c anaconda boost
conda install -n py35 -c conda-forge harfbuzz
conda install -n py35 -c conda-forge freetype
conda install -n py35 -c anaconda hdf5
conda install -n py35 -c omgarcia gcc-6
conda install -n py35 -c anaconda atlas
conda install -n py35 -c conda-forge doxygen
conda install -n py35 -c anaconda openblas
conda install -n py35 -c conda-forge gtk2
conda install -n py35 -c pkgw-forge gtk3
conda install -n py35 -c nersc libjasper
```
5. [安装OpenCV]
# cmake里面的路径记得修改哦
# 这个版本安装完后cv2.VideoCapture()有一定概率不好用，因为WITH_V4L被设置成了OFF。但是，WITH_V4L设置成ON会导致编译不成功，需要sudo权限来四处挪一挪呀改一改。所以，暂时抛弃VideoCapture()功能。：( 有大神解决了这个问题的话请一定要告诉我！感谢！
```
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/path-to-where-you-extract-opencv/opencv-3.4.0 -D INSTALL_PYTHON_EXAMPLES=OFF -D INSTALL_C_EXAMPLES=OFF -D OPENCV_EXTRA_MODULES_PATH=/path-to-where-you-extract-opencv/opencv_contrib-3.4.0/modules -D PYTHON3_EXECUTABLE=/path-to-your-anaconda/envs/py35/bin/python3.5m -D PYTHON3_LIBRARY=/path-to-your-anaconda/envs/py35/lib/libpython3.5m.so -D PYTHON3_INCLUDE_DIR=/path-to-your-anaconda/envs/py35/include/python3.5m -D PYTHON3_NUMPY_INCLUDE_DIRS=/path-to-your-anaconda/envs/py35/lib/python3.5/site-packages/numpy/core/include -D PYTHON3_PACKAGES_PATH=/path-to-your-anaconda/envs/py35/lib/python3.5/site-packages -D WITH_V4L=OFF -D WITH_LIBV4L=ON -D BUILD_EXAMPLES=OFF -D ENABLE_PRECOMPILED_HEADERS=OFF -D CUDA_NVCC_FLAGS=--expt-relaxed-constexpr ..
make -j32
make install
```
6. [完成OpenCV 安装]
```
locate cv2.cpython-35m-x86_64-linux-gnu.so
```
# 上述.so文件应该在 xxx/python3.5/site-packages/
# 当找到多个地址时，每个文件夹都要修改
```
cd /path/to/cv2.cpython-35m-x86_64-linux-gnu.so
mv cv2.cpython-35m-x86_64-linux-gun.so cv2.so
```
7. [使用OpenCV]
```
source activate py35
```
# 然后在py35环境下自由的玩耍OpenCV吧 ~
8. [Trouble Shooting]
来这里看cmake的错误报告: /path-to-where-you-extract-opencv/opencv-3.4.0/build/CMakeFiles/CMakeError.log
8.1. /usr/bin/ld: cannot find –lxxxxx
https://stackoverflow.com/questions/16710047/usr-bin-ld-cannot-find-lnameofthelibrary
# 先看一下缺少的库是怎么个调取方法
```
ld -lxxxxx --verbose
```
解决方案 : a. 将调取方法里面某一个顺眼的路径加到 LD_LIBRARY_PATH中 （前提是该库文件在这个顺眼的路径下面）
b. If you are root, then change the name or add a symbolink
```
sudo ln -s /usr/lib/libz.so.1.2.8 /usr/lib/libzlib.so
```
8.2. -++++++-FOR OPENCV-3.1.0-ONLY-++++++-
BUG: ffmpeg/avformat.h not found:
解决方案:
```
mkdir /usr/include/ffmpeg
cd /usr/include/ffmpeg
sudo ln -sf /usr/include/x86_64-linux-gnu/libavcodec/*.h ./
sudo ln -sf /usr/include/x86_64-linux-gnu/libavformat/*.h ./
sudo ln -sf /usr/include/x86_64-linux-gnu/libswscale/*.h ./
sudo ln -s /usr/include/ffmpeg/*.h /usr/include/x86_64-linux-gnu/ffmpeg
```