sd卡最好先拓展容量：http://www.jianshu.com/p/d8f4f928e2df
编译安装opencv教程见（我没有使用沙箱），http://blog.csdn.net/talkxin/article/details/50471986
我没有使用沙箱，但我用了pyenv，注意一点，使用pyenv安装python时，记得添加生成动态库选项（想了解的看参考链接），opencv的库链接时要用。
compile command for python3.5:
cmake -D CMAKE_BUILD_TYPE=Release \
-D CMAKE_INSTALL_PREFIX=/usr/local \
-D OPENCV_EXTRA_MODULES_PATH=~/opencv_contrib-3.1.0/modules \
-D PYTHON3_EXCUTABLE=/usr/bin/python3 \
-D PYTHON_INCLUDE_DIR=/usr/include/python3.5 \
-D PYTHON_LIBRARY=/usr/lib/python3.5/config-3.5m-arm-linux-gnueabihf/libpython3.5.so \
-D PYTHON3_NUMPY_INCLUDE_DIRS=/usr/lib/python3/dist-packages/numpy/core/include \
-D INSTALL_C_EXAMPLES=OFF \
-D INSTALL_PYTHON_EXAMPLES=ON \
-D BUILD_EXAMPLES=ON ..
after install python3.4.5 through pyenv, the cmake commands:
cmake -D CMAKE_BUILD_TYPE=Release \
-D CMAKE_INSTALL_PREFIX=/usr/local \
-D OPENCV_EXTRA_MODULES_PATH=~/opencv_contrib-3.1.0/modules \
-D PYTHON3_EXCUTABLE=~/.pyenv/versions/3.4.5/bin/python3 \
-D PYTHON_INCLUDE_DIR=~/.pyenv/versions/3.4.5/include/python3.4m \
-D PYTHON_LIBRARY=~/.pyenv/versions/3.4.5/lib/libpython3.4m.so \
-D PYTHON3_NUMPY_INCLUDE_DIRS=~/.pyenv/versions/3.4.5/lib/python3.4/site-packages/numpy/core/include \
-D INSTALL_C_EXAMPLES=OFF \
-D INSTALL_PYTHON_EXAMPLES=ON \
-D BUILD_EXAMPLES=ON ..
注意，由于cmake中设置的安装目录是/usr/local/，故安装后记得链接.so file:
cd ~/.pyenv/versions/3.4.5/lib/python3.4/site-packages
ln -s /usr/local/lib/python3.4/site-packages/cv2.cpython-34m.so
Reference:
官方安装教程：http://docs.opencv.org/3.1.0/d7/d9f/tutorial_linux_install.html
pyenv: http://www.jianshu.com/p/acdb01b1f8a5
