在CentOS上安装OpenCV涉及多个步骤，包括安装必要的依赖包、下载和编译OpenCV源码以及配置环境变量，以下是详细的指南：
一、安装依赖包
1、安装系统依赖
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- sudo yum y install epelrelease
- sudo yum y install gcc gccc++ kerneldevel gccessential gccgfortran
- sudo yum y install cmake make bzip2 zip unzip
- sudo yum y install libjpegturbodevel libtiffdevel libpngdevel libv4ldevel
- sudo yum y install openexrdevel gtk2devel gtk3devel
- sudo yum y install libavcodecdevel libavformatdevel libswscaledevel libdc1394devel libtheoradevel
- sudo yum y install libvorbisdevel xvidcoredevel x264devel frei0rdevel sphinxdevel
- sudo yum y install flacdevel opusdevel og sudo yum y install libaomdevel libvpxdevel ffmpegdevel nasm yasm
- sudo yum y install python3devel numpy
2、安装FFmpeg
- sudo yum localinstall nogpgcheck https://download1.rpmfusion.org/free/el/rpmfusionfreerelease7.noarch.rpm
- sudo yum localinstall nogpgcheck https://download1.rpmfusion.org/nonfree/el/rpmfusionnonfreerelease7.noarch.rpm
- rpm import http://li.nux.ro/download/nux/RPMGPGKEYnux.ro
- sudo yum y install ffmpeg ffmpegdevel
二、下载和编译OpenCV
1、下载OpenCV源码
- cd /opt
- wget https://github.com/opencv/opencv/archive/4.5.0.zip
- unzip 4.5.0.zip
- mv opencv4.5.0 opencv
- cd opencv
- git clone https://github.com/opencv/opencv_contrib.git
2、创建构建目录并进入
- mkdir build
- cd build
3、配置编译选项
- cmake D CMAKE_BUILD_TYPE=Release \
- D CMAKE_INSTALL_PREFIX=/usr/local \
- D INSTALL_C_EXAMPLES=ON \
- D INSTALL_PYTHON_EXAMPLES=ON \
- D BUILD_EXAMPLES=ON \
- D OPENCV_GENERATE_PKGCONFIG=ON \
- D WITH_TBB=ON \
- D WITH_GTK=ON \
- D ENABLE_FAST_MATH=1 \
- D CUDA_FAST_MATH=1 \
- ..
4、编译和安装
- make j$(nproc)
- sudo make install
- sudo ldconfig
三、配置环境变量
1、添加库路径
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- sudo ln s /usr/local/lib64/pkgconfig/opencv4.pc /usr/share/pkgconfig/
- sudo sh c 'echo "export PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig:$PKG_CONFIG_PATH" >> /etc/profile'
- sudo sh c 'echo "export LD_LIBRARY_PATH=/usr/local/lib64:$LD_LIBRARY_PATH" >> /etc/profile'
- source /etc/profile
2、验证安装
- pkgconfig modversion opencv4
四、使用OpenCV编写C++图像处理程序
1、创建项目结构
- mkdir ~/opencv_projects
- cd ~/opencv_projects
- mkdir my_image_processor
- cd my_image_processor
2、编写CMakeLists.txt
- cmake_minimum_required(VERSION 3.1)
- project(MyImageProcessor)
- find_package(OpenCV REQUIRED)
- include_directories(${OpenCV_INCLUDE_DIRS})
- add_executable(my_image_processor main.cpp)
- target_link_libraries(my_image_processor ${OpenCV_LIBS})
3、编写main.cpp
- #include <opencv2/opencv.hpp>
- #include <iostream>
- int main() {
- cv::Mat image = cv::imread("path_to_your_image.jpg");
- if (image.empty()) {
- std::cout << "Could not read the image" << std::endl;
- return 1;
- }
- cv::imshow("Display window", image);
- cv::waitKey(0);
- return 0;
- }
4、编译和运行
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- mkdir build
- cd build
- cmake ..
- make
- ./my_image_processor
五、相关FAQ问答
Q1: 如何更改OpenCV的安装路径？
A1: 在执行cmake命令时，使用D CMAKE_INSTALL_PREFIX选项来指定安装路径。D CMAKE_INSTALL_PREFIX=/custom/path。
Q2: 如果编译过程中出现错误怎么办？
A2: 确保所有依赖项都已正确安装，并且检查cmake输出以确定具体的错误信息，常见的问题包括缺少开发包或路径配置错误，根据错误信息调整配置并重新编译。
Q3: 如何更新OpenCV到最新版本？
A3: 访问OpenCV官网或GitHub仓库，下载最新版本的源码，然后按照上述步骤重新编译和安装，确保先卸载旧版本以避免冲突。
