Ubuntu 18.04 下安装opencv 3.4.10，以及多版本安装和编写CmakeLists.txt问题，最后介绍如何彻底卸载opencv。

帮高师妹搭环境，希望她能送我一篇毕业论文 [doge]

一、源码下载

OpenCV官网
​

github地址
​

或者直接下载
​

二、安装依赖

官方编译安装说明

• 安装依赖

  sudo apt install build-essential
  
  sudo apt install libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
  
  sudo apt install python-dev python-numpy libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-dev
  

  error：无法定位软件包 libjasper-dev：
  sudo add-apt-repository "deb http://security.ubuntu.com/ubuntu xenial-security main"
  再次运行第3步。

三、编译安装

• 解压源码

  tar xvzf opencv-3.4.10.tar.gz
  

• 将解压后的包移动到/opt

  sudo mv opencv-3.4.10 /opt
  

• 创建编译文件夹

  cd /opt/opencv-3.4.10
  
  mkdir build && cd build/
  

• 编译

  # cmake -DWITH_GTK_2_X=ON -DCMAKE_INSTALL_PREFIX=/usr/local ..
  cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_GTK=ON ..
  # CMAKE_BUILD_TYPE=RELEASE：表示编译发布版本
  # CMAKE_INSTALL_PREFIX：表示生成动态库的安装路径，可以自定义
  # WITH_GTK=ON：这个配置是为了防止GTK配置失败：即安装了libgtk2.0-dev依赖，还是报错未安装
  # OPENCV_GENERATE_PKGCONFIG=YES：表示自动生成OpenCV的pkgconfig文件，否则需要自己手动生成。
  
  # 线程数最好大点，加快速度，查看cpu线程： 
  # grep 'processor' /proc/cpuinfo | sort -u | wc -l
  make -j12
  
  sudo make install
  

• 查看安装结果路径

  pkg-config --cflags --libs opencv
  
  sudo find / -iname "*opencv*"
  

四、配置

• 第一种将opencv库添加到系统路经方法

  sudo gedit /etc/ld.so.conf.d/opencv.conf
  
  添加：
  /usr/local/lib
  
  sudo ldconfig
  

• 第二种将opencv库添加到系统路经方法

  sudo gedit /etc/ld.so.conf.d
  
  添加：
  include /etc/ld.so.conf.d/*.conf
  include /usr/local/lib
  # cmake编译时填的动态库安装路径加上/lib
  
  sudo ldconfig
  

• 添加环境变量

  sudo gedit /etc/bash.bashrc
  
  添加：export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
  
  source /etc/bash.bashrc
  

五、测试

• 查看opencv版本

  pkg-config opencv --modversion
  

• 运行源码示例

  cd /opt/opencv-3.4.10/smaples/cpp/example_cmake
  
  cmake .
  
  make -j12
  
  ./opencv_example
  

  报错：Gtk-Message: Failed to load module "canberra-gtk-module"
  解决方法：sudo apt-get install libcanberra-gtk-module

• demo测试

  // main.cpp
  
  #include <stdio.h>
  #include <opencv2/opencv.hpp>
  
  using namespace cv;
  
  int main()
  {
      Mat image;
      image = imread("../1.png");
      if(!image.data)
      {
          printf("No image data \n");
          return -1;
      }
      namedWindow("Display Image",WINDOW_AUTOSIZE);
      imshow("Display Image",image);
      cvWaitKey(0);
      return 0;
  }
  

  # CMakeLists.txt
  
  cmake_minimum_required(VERSION 3.10)
  
  project(test_opencv)
  
  find_package(OpenCV REQUIRED)
  INCLUDE_DIRECTORIES(${OpenCV_INCLUDE_DIRS})
  
  add_executable(${PROJECT_NAME} main.cpp)
  target_link_libraries(${PROJECT_NAME} ${OpenCV_LIBS})
  

六、安装多版本opencv

• OpenCV多版本共存(3.4.10 和 4.1.5)：

  # 调用4.1.5时：
  
  sudo gedit ~/.bashrc
  
  在文件末尾加上：
  export PKG_CONFIG_PATH=/opt/opencv-4.1.5/build/lib/pkgconfig
  export LD_LIBRARY_PATH=/opt/opencv-4.1.5/build/lib
  
  source ~/.bashrc
  
  # 想用之前的(3.4.10)，注释这两行就行
  
  # 查询OpenCV的版本
  pkg-config --modversion opencv
  # 3.4.10
  pkg-config --modversion opencv4
  # 4.1.5
  

• CMakeLists.txt 编写

  # 只有一个版本的OpenCV：
  find_package(OpenCV REQUIRED)
  # 会自动生成OpenCVConfig.cmake文件，其指定了CMake找OpenCV的路径，其.h文件在哪等
  
  # 多版本OpenCV时，需要找到所需版本对应的OpenCVConfig.cmake文件，
  # 并将其路径添加到工程的CMakeLists.txt中：
  set(OpenCV_DIR "/opt/opencv-4.1.5/build")  
  find_package(OpenCV REQUIRED) 
  include_directories(${OpenCV_INCLUDE_DIRS})
  

七、彻底卸载opencv

• 第一种自动卸载

  # 如果删掉了build，再安装上面编译生成一个
  cd /opt/opencv-3.4.10/build
  
  sudo make uninstall
  
  cd ..
  
  sudo rm -r build
  

• 第二种手动卸载

  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*
  

• 第三种卸载手动卸载

  # 会删除python的opencv环境
  
  sudo apt autoremove opencv-doc opencv-data libopencv-dev libopencv2.4-java libopencv2.4-jni python-opencv libopencv-core2.4 libopencv-gpu2.4 libopencv-ts2.4 libopencv-photo2.4 libopencv-contrib2.4 libopencv-imgproc2.4 libopencv-superres2.4 libopencv-stitching2.4 libopencv-ocl2.4 libopencv-legacy2.4 libopencv-ml2.4 libopencv-video2.4 libopencv-videostab2.4 libopencv-objdetect2.4 libopencv-calib3d2.4
  

• 手动确定删除哪些

  sudo find / -name "*opencv*" -exec rm -i {} \
  

• 直接删除

  cd /usr
  
  find . -name "*opencv*" | xargs sudo rm -rf
  

• 检查是否卸载完成

  pkg-config opencv --libs
  
  pkg-config opencv --modversion