sudo yum -y install epel-release			# 安装epel扩展源
sudo yum -y install git gcc gcc-c++ cmake3
sudo yum -y install qt5-qtbase-devel
sudo yum install -y python34 python34-devel python34-pip
sudo yum install -y python python-devel python-pip
sudo yum -y install python-devel numpy python34-numpy
sudo yum -y install gtk2-devel
sudo yum install -y libpng-devel
sudo yum install -y jasper-devel
sudo yum install -y openexr-devel
sudo yum install -y libwebp-devel
sudo yum -y install libjpeg-turbo-devel 
sudo yum install -y freeglut-devel mesa-libGL mesa-libGL-devel
sudo yum -y install libtiff-devel 
sudo yum -y install libdc1394-devel
sudo yum -y install tbb-devel eigen3-devel
sudo yum -y install boost boost-thread boost-devel
sudo yum -y install libv4l-devel
sudo yum -y install gstreamer-plugins-base-devel
sudo rpm --import http://li.nux.ro/download/nux/RPM-GPG-KEY-nux.ro
sudo rpm -Uvh http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-5.el7.nux.noarch.rpm
yum -y install ffmpeg ffmpeg-devel	# 安装ffmpeg依赖【必须】

这个很慢，可以源码下载，然后编译安装

git clone https://github.com/opencv/opencv.git
cd opencv
git checkout master			# 选择master版本分支
cd ..
git clone https://github.com/opencv/opencv_contrib.git
cd opencv_contrib
git checkout master			# 选择master版本分支
cd ..

cd opencv-4.3.0/
mkdir build
cd build

cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local  -D OPENCV_EXTRA_MODULES_PATH=../opencv_contrib/modules/ -D WITH_TBB=OFF  -D WITH_CUDA=OFF -D BUILD_opencv_gpu=OFF -D BUILD_opencv_gpuarithm=OFF -D OPENCV_GENERATE_PKGCONFIG=ON .. 

# 生成静态库
# cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local  -DBUILD_SHARED_LIBS=OFF -DBUILD_TESTS=OFF -D OPENCV_EXTRA_MODULES_PATH=../opencv_contrib/modules/ -D WITH_TBB=OFF  -D WITH_CUDA=OFF -D BUILD_opencv_gpu=OFF -D BUILD_opencv_gpuarithm=OFF -D OPENCV_GENERATE_PKGCONFIG=ON .. 

make -j$(nproc)			#有几个CPU就用几个CPU
make install

cmake编译选项（ON是开(机)的意思; OFF是关(机)的意思）

• -D CMAKE_BUILD_TYPE=RELEASE

  • 编译模式，release/debug， 默认为release

• -D CMAKE_INSTALL_PREFIX=/usr/local

  • 安装路径

• -D WITH_TBB=ON #Include Intel TBB support

  • （Intel开发的并行编程开发工具），默认为off

• -D BUILD_TIFF=ON

• Build libtiff from source（一种灵活的位图格式），默认为ON

• -D WITH_V4L=ON

• 支持Vedio4Linux(是Linux中关于视频设备的内核驱动，为针对视频设备的应用视频设备的应用程序提供一系列接口函数，这些视频设备包括TV卡、视频捕捉卡和USB摄像头等，对于USB摄像头，其驱动程序中需要提供基本的I/O操作用于open、read、write、close函数的实现)，默认为ON

• -D INSTALL_C_EXAMPLES=ON

• Install C examples， 默认为off

• -D INSTALL_PYTHON_EXAMPLES=ON

• Install Python examples， 默认为off

• -D BUILD_EXAMPLES=ON

• Build all examples， 默认为off

• -D WITH_QT=ON

/ #支持QT（c++图像用户界面开发框架，多用于开发GUI），默认为off

• -D WITH_GTK=ON

• 支持跨平台通用图形工具包GTK， 默认为on

• -D WITH_OPENGL=ON

• 支持开放图形库OpenGL，默认为off …

• -D OPENCV_GENERATE_PKGCONFIG=ON

• Linux下我们使用opencv，需要使用pkg-config来进行环境变量的管理,这个软件需要.pc类型的文件作为软件配置信息
  生成opencv.pc文件的配置(注意，opencv4生成的文件叫做opencv4.pc)

CMake Error at cmake_install.cmake:41 (file):
  file cannot create directory: /usr/local/share/licenses/opencv3.  Maybe
  need administrative privileges.

需要su权限

 IPPICV: Download: ippicv_2020_lnx_intel64_20191018_general.tgz
-- Try 1 failed
-- 
=======================================================================
  Couldn't connect to server from the Internet.
  Perhaps direct connections are not allowed in the current network.
  To use proxy please check/specify these environment variables:
  - http_proxy/https_proxy
  - and/or HTTP_PROXY/HTTPS_PROXY

# cd ../.cache/ippicv/
# ls -l

1、手动下载

CMake Error at cmake/OpenCVModule.cmake:288 (message):
  No modules has been found:
  /home/oceanstar/workspace/opencv-4.3.0/opencv_contrib/modules
Call Stack (most recent call first):
  cmake/OpenCVModule.cmake:370 (_glob_locations)
  modules/CMakeLists.txt:7 (ocv_glob_modules)

将opencv_contrib放到opencv-4.3.0之下

~/opencv_contrib/modules/xfeatures2d/src/boostdesc.cpp:673:20: fatal error: boostdesc_bgm.i: No such file or directory

Make Warning at cmake/OpenCVDownload.cmake:202 (message):
  data: Download failed: 28;"Timeout was reached"

  For details please refer to the download log file:

  /home/oceanstar/workspace/opencv/build/CMakeDownloadLog.txt

Call Stack (most recent call first):
  opencv_contrib/modules/face/CMakeLists.txt:13 (ocv_download)


CMake Warning at opencv_contrib/modules/face/CMakeLists.txt:26 (message):
  Face: Can't get model file for face alignment.

替换，然后opencv_contrib/modules/face/CMakeLists.txt:13 (ocv_download)注释掉

fatal error: features2d/test/test_detectors_regression.impl.hpp: 没有那个文件或目录

#include "features2d/test/test_detectors_regression.impl.hpp"

头文件include地址不对，解决方法如下：

将opencv-4.1.0/modules/features2d/test/文件下的

test_descriptors_invariance.impl.hpp
test_descriptors_regression.impl.hpp
test_detectors_invariance.impl.hpp
test_detectors_regression.impl.hpp
test_invariance_utils.hpp

拷贝到opencv_contrib-4.1.0/modules/xfeatures2d/test/文件下。

同时，将opencv_contrib-4.1.0/modules/xfeatures2d/test/test_features2d.cpp文件下的

#include "features2d/test/test_detectors_regression.impl.hpp"
#include "features2d/test/test_descriptors_regression.impl.hpp"

改成：

#include "test_detectors_regression.impl.hpp"
#include "test_descriptors_regression.impl.hpp"

将opencv_contrib-4.1.0/modules/xfeatures2d/test/test_rotation_and_scale_invariance.cpp文件下的

#include "features2d/test/test_detectors_invariance.impl.hpp" 
#include "features2d/test/test_descriptors_invariance.impl.hpp"

改成

#include "test_detectors_invariance.impl.hpp"
#include "test_descriptors_invariance.impl.hpp"

下面的方法没有用，老老实实改目录吧【和上面的方法一样】

打开 /home/oceanstar/CLionProjects/opencv-3.4.0/modules/stitching 下的CMakeLists.txt

添加 ： INCLUDE_DIRECTORIES("/home/oceanstar/CLionProjects/opencv-3.4.0/opencv_contrib/modules/xfeatures2d/include")

– No package ‘gtk±3.0’ found

解决：

 yum install gtk3-devel

mkdir tt && cd tt
vi DisplayImage.cpp

#include <stdio.h>
#include <opencv2/opencv.hpp>
using namespace cv;
int main(int argc, char** argv )
{
    if ( argc != 2 )
    {
        printf("usage: DisplayImage.out <Image_Path>n");
        return -1;
    }
    Mat image;
    image = imread( argv[1], 1 );
    if ( !image.data )
    {
        printf("No image data n");
        return -1;
    }
    namedWindow("Display Image", WINDOW_AUTOSIZE );
    imshow("Display Image", image);
    waitKey(0);
    return 0;
}

vi CMakeLists.txt

set(CMAKE_CXX_STANDARD 14)								#设置c++标准为14
cmake_minimum_required(VERSION 2.8)
project( DisplayImage )
find_package( OpenCV REQUIRED )
include_directories( ${OpenCV_INCLUDE_DIRS} )
add_executable( DisplayImage DisplayImage.cpp )
target_link_libraries( DisplayImage ${OpenCV_LIBS} )

cmake 并测试如下：

[root@localhost tt]# cmake3 .
-- The C compiler identification is GNU 4.8.5
-- The CXX compiler identification is GNU 4.8.5
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Found OpenCV: /usr/local (found version "4.1.1")
-- Configuring done
-- Generating done
-- Build files have been written to: /root/tt

[root@localhost tt]# make
Scanning dependencies of target DisplayImage
[ 50%] Building CXX object CMakeFiles/DisplayImage.dir/DisplayImage.cpp.o
[100%] Linking CXX executable DisplayImage
[100%] Built target DisplayImage

[root@localhost tt]# ./DisplayImage lena.jpg
(Display Image:7859): Gtk-WARNING **: 09:04:15.519: cannot open display:

#include <iostream>
#include <vector>

#include <opencv2/xfeatures2d.hpp>
#include <opencv2/opencv.hpp>

using namespace cv;
using namespace std;

int main()
{

    Mat img = imread("/home/oceanstar/CLionProjects/object-detection-SIFT-master/image.png",cv::IMREAD_COLOR);
    Ptr<Feature2D> sift = xfeatures2d::SIFT::create();
    vector<cv::KeyPoint> keypoints;
    Mat descriptors;

    sift->detectAndCompute(img, cv::noArray(),keypoints, descriptors);
    cv::drawKeypoints(img,keypoints,descriptors,cv::Scalar(0, 255, 255));
    imshow("Result", descriptors);

    waitKey();
    return 0;
}

# make uninstall

pkg-config opencv4 --cflags --libs