Ubuntu16.04安装opencv-3.4.2

原文链接：

https://m.oldpan.me/archives/ubuntu-install-opencv-from-source

第一步：更新我们的系统

sudo apt-get update
sudo apt-get upgrade

第二步：安装所有依赖库

# 首先我们先移除系统中已经存在的依赖，这一部必须要做
sudo apt-get remove x264 libx264-dev
 
# 然后安装我们需要的依赖
sudo apt-get install build-essential checkinstall cmake pkg-config yasm
sudo apt-get install git gfortran
sudo apt-get install libjpeg8-dev libjasper-dev libpng12-dev
 
# 下面根据版本选择安装 
#  Ubuntu 14.04
sudo apt-get install libtiff4-dev
#  Ubuntu 16.04
sudo apt-get install libtiff5-dev
 
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libdc1394-22-dev
sudo apt-get install libxine2-dev libv4l-dev
sudo apt-get install libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev
sudo apt-get install qt5-default libgtk2.0-dev libtbb-dev
sudo apt-get install libatlas-base-dev
sudo apt-get install libfaac-dev libmp3lame-dev libtheora-dev
sudo apt-get install libvorbis-dev libxvidcore-dev
sudo apt-get install libopencore-amrnb-dev libopencore-amrwb-dev
sudo apt-get install x264 v4l-utils
sudo apt-get install qt5-default
 
# 可选安装
sudo apt-get install libprotobuf-dev protobuf-compiler
sudo apt-get install libgoogle-glog-dev libgflags-dev
sudo apt-get install libgphoto2-dev libeigen3-dev libhdf5-dev doxygen

第三步：安装python依赖(可选)

sudo apt-get install python3-dev
pip3 install numpy scipy matplotlib scikit-image scikit-learn ipython

第四步：下载opencv-3.4.2

https://opencv.org/releases.html

第五步：安装opencv-3.4.2

１）进入我们的opencv目录，创建一个build的文件夹并进入

cd opencv
mkdir build
cd build   

２）cmake配置

cmake -D CMAKE_BUILD_TYPE=Release -D MAKE_INSTALL_PREFIX=/usr/local ..

３）等待漫长的编译过程

make

４）安装

sudo make install

５）环境配置添加库路径

sudo sh -c 'echo "/usr/local/lib" >> /etc/ld.so.conf.d/opencv.conf'

６）更新系统库

sudo ldconfig

７）配置bash

sudo vim /etc/bash.bashrc
//在末尾添加
PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
export PKG_CONFIG_PATH

保存退出，然后执行如下命令使得配置生效

source /etc/bash.bashrc
//激活配置然后更新database
sudo updatedb

第六步：测试

１）在home下新建文件夹进入并新建名称为opencv_test.cpp

#include <iostream>
#include <opencv2/opencv.hpp>

using namespace cv;
using namespace std;

int main(int argc, char** argv)
{

    if ( argc != 2 )
    {
        cout << "Need to load a picture..." << endl;
        return -1;
    }
    Mat image;
    image = imread( argv[1], 1 );
    if ( image.empty() )
    {
        cout<<"No image data!"<< endl;
        return -1;
    }
    namedWindow("Display Image", WINDOW_AUTOSIZE );
    imshow("Display Image", image);
    waitKey(0);
    return 0;
}

２）建立一个CMakeLists.txt文件

cmake_minimum_required(VERSION 2.8)

project( DisplayImage )

find_package( OpenCV REQUIRED )

add_executable( opencv_test opencv_test.cpp )

target_link_libraries( opencv_test ${OpenCV_LIBS} )

３）在home目录中放一张测试的图片，例如test.jpg，分别执行

cmake .
make
./opencv_test ~/test.jpg

图片显示成功！

在opencv_test.cpp文件创建成功后，或可直接使用如下命令生成可执行程序

g++ `pkg-config opencv --cflags` opencv_test.cpp  -o opencv_test `pkg-config opencv --libs`

注意：这里是` `（Tab键上面的那个键），而不是单引号' '

卸载源码安装的opencv

在之前创建的build目录中执行

sudo make uninstall

如果卸载不干净，则执行下面的命令：

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*

在编译过程中可能遇到的问题

Scanning dependencies of target opencv_cudafilters
[ 45%] Building CXX object modules/cudafilters/CMakeFiles/opencv_cudafilters.dir/src/filtering.cpp.o
cc1plus: warning: /home/prototype/Downloads/opencv-3.4.0/build/modules/cudafilters/precomp.hpp.gch/opencv_cudafilters_RELEASE.gch: not used because 'OPENCV_TRAITS_ENABLE_DEPRECATED' is defined [-Winvalid-pch]
cc1plus: warning: /home/prototype/Downloads/opencv-3.4.0/build/modules/cudafilters/precomp.hpp.gch/opencv_cudafilters_Release.gch: not used because 'OPENCV_TRAITS_ENABLE_DEPRECATED' is defined [-Winvalid-pch]
[ 45%] Linking CXX shared library ../../lib/libopencv_cudafilters.so
[ 45%] Built target opencv_cudafilters
Makefile:162: recipe for target 'all' failed
make: *** [all] Error 2

遇到上面的问题，一般是之前OpenCV残留没有删除干净，删除干净重来即可。