Ubuntu16.04安装Opencv3.4.1教程

一、编译安装

1.官网下载sources版本(For Linux)：http://opencv.org/releases.html

2.解压：

unzip opencv-3.4.1.zip 

3.进入：

cd opencv-3.4.1.zip

4.安装cmake工具: 

sudo apt-get install cmake

5.安装依赖库：

sudo apt-get install build-essential libgtk2.0-dev libavcodec-dev libavformat-dev libjpeg.dev libtiff4.dev libswscale-dev libjasper-dev

6.创建编译目录(release)并进入：

mkdir release && cd release

7.cmake配置编译：

cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D WITH_V4L=ON -D WITH_QT=ON -D WITH_OPENGL=ON ..

8.make编译：

make -j$(nproc)
// nproc是读取CPU的核心数量 

9.安装：

sudo make install

10.环境配置添加库路径(方式一)：

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

10.环境配置添加库路径(方式二)：

sudo gedit /etc/ld.so.conf.d/opencv.conf 
//打开后可能是空文件，在文件内容最后添加
/usr/local/lib

11.更新系统库： 

sudo ldconfig

12.配置bash，执行如下命令

sudo gedit /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

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

参考：https://blog.csdn.net/keith_bb/article/details/52685231

二、测试

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;
}

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} )

在桌面上放一张测试的图片，例如test.jpg，分别执行

cmake .

make

./opencv_test test.jpg

即可显示图片

三、问题记录

1.Qt5Core编译错误

CMake Warning at cmake/OpenCVFindLibsGUI.cmake:18 (find_package):
By not providing "FindQt5Core.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "Qt5Core", but
CMake did not find one.

Could not find a package configuration file provided by "Qt5Core" with any
of the following names:

Qt5CoreConfig.cmake
qt5core-config.cmake

Add the installation prefix of "Qt5Core" to CMAKE_PREFIX_PATH or set
"Qt5Core_DIR" to a directory containing one of the above files.  If
"Qt5Core" provides a separate development package or SDK, be sure it has
been installed.
Call Stack (most recent call first):
CMakeLists.txt:466 (include)

CMake Warning at cmake/OpenCVFindLibsGUI.cmake:19 (find_package):
By not providing "FindQt5Gui.cmake" in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by "Qt5Gui", but
CMake did not find one.

Could not find a package configuration file provided by "Qt5Gui" with any
of the following names:

  Qt5GuiConfig.cmake
  qt5gui-config.cmake

Add the installation prefix of "Qt5Gui" to CMAKE_PREFIX_PATH or set
"Qt5Gui_DIR" to a directory containing one of the above files.  If "Qt5Gui"
provides a separate development package or SDK, be sure it has been
installed.
Call Stack (most recent call first):
CMakeLists.txt:466 (include)


CMake Warning at cmake/OpenCVFindLibsGUI.cmake:20 (find_package):
By not providing "FindQt5Widgets.cmake" in CMAKE_MODULE_PATH this project
has asked CMake to find a package configuration file provided by
"Qt5Widgets", but CMake did not find one.

Could not find a package configuration file provided by "Qt5Widgets" with
any of the following names:

  Qt5WidgetsConfig.cmake
  qt5widgets-config.cmake

Add the installation prefix of "Qt5Widgets" to CMAKE_PREFIX_PATH or set
"Qt5Widgets_DIR" to a directory containing one of the above files.  If
"Qt5Widgets" provides a separate development package or SDK, be sure it has
been installed.

Call Stack (most recent call first):

  CMakeLists.txt:466 (include)

CMake Warning at cmake/OpenCVFindLibsGUI.cmake:21 (find_package):

  By not providing "FindQt5Test.cmake" in CMAKE_MODULE_PATH this project has asked CMake to find a package configuration file provided by "Qt5Test", but

  CMake did not find one.

  Could not find a package configuration file provided by "Qt5Test" with any

  of the following names:

Qt5TestConfig.cmake
qt5test-config.cmake

Add the installation prefix of "Qt5Test" to CMAKE_PREFIX_PATH or set
"Qt5Test_DIR" to a directory containing one of the above files.  If
"Qt5Test" provides a separate development package or SDK, be sure it has
been installed.
Call Stack (most recent call first):
  CMakeLists.txt:466 (include)


CMake Warning at cmake/OpenCVFindLibsGUI.cmake:22 (find_package):
  By not providing "FindQt5Concurrent.cmake" in CMAKE_MODULE_PATH this
  project has asked CMake to find a package configuration file provided by
  "Qt5Concurrent", but CMake did not find one.

  Could not find a package configuration file provided by "Qt5Concurrent"
  with any of the following names:

    Qt5ConcurrentConfig.cmake
    qt5concurrent-config.cmake

  Add the installation prefix of "Qt5Concurrent" to CMAKE_PREFIX_PATH or set
  "Qt5Concurrent_DIR" to a directory containing one of the above files.  If
  "Qt5Concurrent" provides a separate development package or SDK, be sure it
  has been installed.
  Call Stack (most recent call first):
  CMakeLists.txt:466 (include)

qmake: could not exec '/usr/lib/x86_64-linux-gnu/qt4/bin/qmake': No such file     or         directory
CMake Error at /usr/share/cmake-2.8/Modules/FindQt4.cmake:1386 (message):
  Found unsuitable Qt version "" from NOTFOUND, this code requires Qt 4.x
Call Stack (most recent call first):
  cmake/OpenCVFindLibsGUI.cmake:34 (find_package)
  CMakeLists.txt:466 (include)

-- Configuring incomplete, errors occurred!
See also "/home/*******/OpenCV/opencv-2.4.9/build/CMakeFiles/CMakeOutput.log".
See also "/home/*******/OpenCV/opencv-2.4.9/build/CMakeFiles/CMakeError.log".

解决方式：

qt5-default：sudo apt-get install qt5-default

 参考地址：https://stackoverflow.com/questions/24378473/ubuntu-opencv-install-and-setup-qt5