安装opencv
参考：https://milq.github.io/install-opencv-ubuntu-debian/
######################################
# INSTALL OPENCV ON UBUNTU OR DEBIAN #
######################################
# | THIS SCRIPT IS TESTED CORRECTLY ON |
# |------------------------------------------------------|
# | OS | OpenCV | Test | Last test |
# |------------------|--------------|------|-------------|
# | Ubuntu 18.04 LTS | OpenCV 3.4.2 | OK | 18 Jul 2018 |
# | Debian 9.5 | OpenCV 3.4.2 | OK | 18 Jul 2018 |
# |----------------------------------------------------- |
# | Debian 9.0 | OpenCV 3.2.0 | OK | 25 Jun 2017 |
# | Debian 8.8 | OpenCV 3.2.0 | OK | 20 May 2017 |
# | Ubuntu 16.04 LTS | OpenCV 3.2.0 | OK | 20 May 2017 |
# VERSION TO BE INSTALLED
OPENCV_VERSION='3.4.2'
# 1. KEEP UBUNTU OR DEBIAN UP TO DATE
sudo apt-get -y update
sudo apt-get -y upgrade
sudo apt-get -y dist-upgrade
sudo apt-get -y autoremove
# 2. INSTALL THE DEPENDENCIES
# Build tools:
sudo apt-get install -y build-essential cmake
# GUI (if you want to use GTK instead of Qt, replace 'qt5-default' with 'libgtkglext1-dev' and remove '-DWITH_QT=ON' option in CMake):
sudo apt-get install -y qt5-default libvtk6-dev
# Media I/O:
sudo apt-get install -y zlib1g-dev libjpeg-dev libwebp-dev libpng-dev libtiff5-dev libjasper-dev libopenexr-dev libgdal-dev
# Video I/O:
sudo apt-get install -y libdc1394-22-dev libavcodec-dev libavformat-dev libswscale-dev libtheora-dev libvorbis-dev libxvidcore-dev libx264-dev yasm libopencore-amrnb-dev libopencore-amrwb-dev libv4l-dev libxine2-dev
# Parallelism and linear algebra libraries:
sudo apt-get install -y libtbb-dev libeigen3-dev
# Python:
sudo apt-get install -y python-dev python-tk python-numpy python3-dev python3-tk python3-numpy
# Java:
sudo apt-get install -y ant default-jdk
# Documentation:
sudo apt-get install -y doxygen
# 3. INSTALL THE LIBRARY
sudo apt-get install -y unzip wget
wget https://github.com/opencv/opencv/archive/${OPENCV_VERSION}.zip
unzip ${OPENCV_VERSION}.zip
rm ${OPENCV_VERSION}.zip
mv opencv-${OPENCV_VERSION} OpenCV
cd OpenCV
mkdir build
cd build
cmake -DWITH_QT=ON -DWITH_OPENGL=ON -DFORCE_VTK=ON -DWITH_TBB=ON -DWITH_GDAL=ON -DWITH_XINE=ON -DBUILD_EXAMPLES=ON -DENABLE_PRECOMPILED_HEADERS=OFF ..
make -j4
sudo make install
sudo ldconfig
# 4. EXECUTE SOME OPENCV EXAMPLES AND COMPILE A DEMONSTRATION
# To complete this step, please visit 'http://milq.github.io/install-opencv-ubuntu-debian'.
sudo ldconfig
提示
/sbin/ldconfig.real: /usr/local/cuda/lib64/libcudnn.so.5 is not a symbolic link
解决：https://askubuntu.com/questions/1025928/why-do-i-get-sbin-ldconfig-real-usr-local-cuda-lib64-libcudnn-so-7-is-not-a
cd /usr/local/cuda/lib64/
ls -lha libcudnn*
sudo rm libcudnn.so
sudo rm libcudnn.so.5
sudo ln libcudnn.so.5.1.10 libcudnn.so.5
sudo ln libcudnn.so.5 libcudnn.so
cd ~/OpenCV/build/
sudo ldconfig
C++测试
cd ~/Opencv/build/bin
./example_cpp_edge ../../samples/data/fruits.jpg
Java测试：
cd ~/Opencv/samples/java/ant
ant -DocvJarDir=../../../build/bin -DocvLibDir=../../../build/lib
编译demo
Download the files demo.cpp and CMakeLists.txt and put them into folder ~/Opencv/samples/demo.
cd ~/Opencv/samples/demo
mkdir build && cd build && cmake .. && make
./demo
python测试：
cd ~/Opencv/samples/python
python3 video.py
居然
ModuleNotFoundError: No module named 'cv2'
装下面这个好了
pip install opencv-python
这里的cv2并不是版本号，也不是说是python2的包。OpenCV是基于C/C++的。cv表示底层是C API，cv2表示使用的C++API。
