ubantu安装opencv，并配置环境变量

1.安装准备：

1.1安装cmake

sudo apt-get install cmake

1.2依赖环境

sudo apt update  # 只检查，不更新
sudo apt upgrade  # 更新已安装的软件包
sudo apt-get install build-essential  # 提供编译程序必须软件包的列表信息,有了这个软件包它才知道 头文件在哪 才知道库函数在哪
sudo apt install libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libavresample-dev
sudo apt install libxvidcore-dev x264 libx264-dev  libtheora-dev 
sudo apt install libfaac-dev libmp3lame-dev libvorbis-dev libopencore-amrnb-dev 
 libavcodec-dev libavformat-dev libjpeg-dev libswscale-dev libtiff5-dev
sudo apt-get install libgtk2.0-dev # gtk
sudo apt-get install pkg-config  # 包管理

1.3下载opencv

下载地址：https://opencv.org/releases/
这里下载source

2编译过程

2.1创建build

将opencv_contrib-4.4.0移到opencv-4.4.0

cp -r opencv_contrib-4.4.0 opencv-4.4.0

创建build目录

    cd opencv-4.4.0
    mkdir build
    cd build

执行的cmake命令

cmake -DCMAKE_BUILD_TYPE=RELEASE -DCMAKE_INSTALL_PREFIX=~/opencv44/ -DBUILD_JAVA=OFF -DOPENCV_EXTRA_MODULES_PATH=../opencv_contrib-4.4.0/modules -DWITH_CUDA=1 -DENABLE_FAST_MATH=1 -DCUDA_FAST_MATH=1 -DWITH_CUBLAS=1 -DOPENCV_GENERATE_PKGCONFIG=ON -D WITH_GTK=ON  -DWITH_GSTREAMER=ON -DCUDA_GENERATION=Pascal ..

编译安装的地址是~/opencv44/，需要修改一下

make -j8  // 8个线程安装
make install

2.2 添加环境变量

sudo gedit ~/.bashrc

export LD_LIBRARY_PATH=/home/fxy/opencv44/lib
export PKG_CONFIG_PATH=/home/fxy/opencv44/lib/pkgconfig:$PKG_CONFIG_PATH

source ~/.bashrc   // 刷新

2.3 查看

查看linux下的opencv安装库：pkg-config opencv --libs

查看linux下的opencv安装版本：pkg-config opencv --modversion

3.能出现的问题

1. GTK+ 2.x or Carbon support.
   http://t.zoukankan.com/gylei-p-3196887.html
2. libopencv*.so找不到

sudo gedit /etc/ld.so.conf
include /home/fxy/opencv44   # 安装的路径
sudo ldconfig