Ubuntu16.04下安装opencv3.3和opencv_contrib(命令行及cmake-gui安装)及卸载
下载opencv3.3.1及opencv-3.3.contrib
opencv3.3.1
https://github.com/opencv/opencv/releases/tag/3.3.1
选择source code(tar.gz)
opencv_contrib
https://github.com/opencv/opencv_contrib/releases/tag/3.3.1
选择source code(tar.gz)
安装相关依赖包
CTRL+T打开终端，在解压opencv之前输入以下命令，安装相关依赖包，一般装前三个命令就行，一定要确认GTK2.0已经装好
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
sudo apt-get install build-essential qt5-default ccache libv4l-dev libavresample-dev libgphoto2-dev libopenblas-base libopenblas-dev doxygen openjdk-8-jdk pylint libvtk6-dev
sudo apt-get install pkg-config
注意
这儿一定要确定pkg-config和libgtk2.0-dev已经装上，不然后续写程序用了imshow会报错，查了一下只能重装opencv才能解决咯
解压，编译
解压opencv3.3.1及opencv-3.3.contrib
并将opencv3.3.1放到opencv目录下,将opencv-3.3.contrib放到opencv-3.3.1目录下
最后在opencv3.3.1目录下创建一个build文件夹
cd opencv-3.3.1
sudo mkdir build #新建文件夹build
进入build目录
执行cmake生成makefile文件
cd build
sudo cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local -D OPENCV_EXTRA_MODULES_PATH=/home/opencv/opencv-3.3.1/opencv_contrib-3.3.1/modules/ ..
OPENCV_EXTRA_MODULES_PATH就是你 opencv_contrib-3.3.1下面的modules目录,且后面有两个…不能缺少
生成完毕之后,提示如下：
-- Install path: /usr/local
--
-- cvconfig.h is in: /home/user/opencv-3.3.1/build
-- -----------------------------------------------------------------
--
-- Configuring done
-- Generating done
-- Build files have been written to: /home/user/opencv-3.3.1/build
cmake完毕之后，再进行make,在build文件夹下进行make:
sudo make -j16 #16线程编译，这个线程数依据个人电脑配置而定
sudo make install
成功之后再
make install
链接库共享
编译安装完毕之后，为了让你的链接库被系统共享，让编译器发现，需要执行管理命令ldconfig
sudo ldconfig -v
cmake-gui安装opencv及contrib
sudo apt-get install cmake-qt-gui
在提取好的opencv3.3目录下创建build文件夹
mkdir build
cd build
cmake-gui ..
然后会弹出cmake-gui界面
与windows下的opencv安装其实是一样的
先填好路径再configure
这是我之后换的3.4.2版本（别介意，安装方法都是一样的）
这儿需要做以下几步
勾上Nonfree模块
找到opencv_extra_modules_path
在后面的values中添加opencv-contrib中modules的路径，一定要选中modules文件夹
不装cuda的话可以把cuda的勾去了
防止出现.GTK2.0的错误，勾上
在cmake_build_type处填上RELEASE
然后GENERATE
其中可能会遇到IPPICV的问题，一定要确认其装好了，按文末方法解决即可
然后在build下打开终端，最好用root权限执行以下命令，不然容易报错，输入
make -j16
sudo make install
环境变量配置
然后配置环境变量即可
sudo gedit /etc/ld.so.conf.d/opencv.conf
添加以下内容
/usr/local/lib
配置库
sudo ldconfig
更改环境变量
sudo gedit /etc/bash.bashrc
在文件后添加
PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
export PKG_CONFIG_PATH
保存退出，重新开启终端来使配置生效。
到此，安装和配置的整个过程都完成了！
问题
其间可能会遇到许多问题
很多依赖项，如果遇到问题，一个个谷歌百度，一定要学会看控制台输出的命令错误在哪，
比如缺失文件啥的
- ippicv的问题
在下面网站下载对应名称的ippicv文件
https://github.com/opencv/opencv_3rdparty/tree/ippicv/master_20170822/ippicv
保存路径随意，一般是自动放在默认的下载路径/home/user/下载
修改opencv里相关配置文件
打开终端，输入
gedit /home/user/opencv_source/opencv/3rdparty/ippicv/ippicv.cmake #记得user换成自己的用户名
将47行的
"https://raw.githubusercontent.com/opencv/opencv_3rdparty/${IPPICV_COMMIT}/ippicv/"
改为从网站中下载下来的文件的本地路径：
"file:///home/user/下载/" #（根据自己的路径填写）
-
vtk is not found
sudo apt-get install libproj-dev
以及下列问题
The imported target "vtkRenderingPythonTkWidgets" references the file
"/usr/lib/x86_64-linux-gnu/libvtkRenderingPythonTkWidgets.so"
but this file does not exist. Possible reasons include:
* The file was deleted, renamed, or moved to another location.
* An install or uninstall procedure did not complete successfully.
* The installation package was faulty and contained
"/usr/lib/cmake/vtk-6.2/VTKTargets.cmake"
but not all the files it references.
-- The imported target "vtk" references the file
"/usr/bin/vtk"
but this file does not exist. Possible reasons include:
* The file was deleted, renamed, or moved to another location.
* An install or uninstall procedure did not complete successfully.
* The installation package was faulty and contained
"/usr/lib/cmake/vtk-6.2/VTKTargets.cmake"
but not all the files it references.
解决办法：
sudo apt install python-vtk
cmake could not find atlas
解决办法：
cmake -DBLAS=open …
或者直接不管，比如下列问题，因为不需要用上java和matlab,所以就先不管它们
cmake could not find jin(missing: JAVA_AWT_LIBRARY JAVA_JVM_LIBRARY JAVA_INCLUDE_PATH JAVA_INCLUDE_PATH)
cmake could not find matlab
又比如在下载tiny-dnn的时候卡住，用不上神经网络的话可以不装，让它卡一会，等等就可以configure done了
再比如还有以下错误提示
file cannot create directory: /usr/local/include/opencv2. Maybe need
administrative privileges.
Makefile:148: recipe for target 'install' failed
make: *** [install] Error 1
解决办法：
千万要用sudo ，而不能只用make install，不然就报错
sudo make install
另外可能
modules/viz/CMakeFiles/opencv_test_viz.dir/build.make:233: recipe for target 'bin/opencv_test_viz' failed
make[2]: *** [bin/opencv_test_viz] Error 1
CMakeFiles/Makefile2:5627: recipe for target 'modules/viz/CMakeFiles/opencv_test_viz.dir/all' failed
make[1]: *** [modules/viz/CMakeFiles/opencv_test_viz.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs...
解决办法：
sudo apt-get autoremove libtiff5-dev
sudo apt-get install libtiff5-dev
另外可能有一些文件需要更高权限
更改文件夹和子文件夹权限
打开终端进入你需要修改的目录
然后执行下面这条命令
chmod 777 * -R
opencv卸载
1.查看已安装的版本
pkg-config --modversion opencv
2.进入安装opencv的目录的build文件夹
cd /home/***/opencv/build
sudo make uninstall
cd ..
sudo rm -r build
3.清理 /usr 中所有 opencv 相关项
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*
cd /usr
find . -name "*opencv*" | xargs sudo rm -rf
cd /home/***
chmod a+x /home/***/opencv
rm -r /home/***/opencv
4.再查看版本
pkg-config --modversion opencv
此时显示opencv已经not found了