Opencv 4.5.5 linux contrib编译

• https://github.com/opencv/opencv/releases    https://github.com/opencv/opencv_contrib/releases/tag/4.7.0 版本要一模一样
  • 下载4.5.5的源码

# 0. 将contrib文件夹移动到opencv文件夹中去
mkdir build
cd build# 1. cmake生成配置文件，其中OPENCV_EXTRA_MODULES_PATH的路径中写明contrib模块的路径
cmake -DCMAKE_INSTALL_PREFIX=/usr/local -DCMAKE_BUILD_TYPE=Release -D OPENCV_EXTRA_MODULES_PATH=../opencv_contrib-4.5.5/modules ..# 2. 编译和生成
make -j16
# 3. 安装
sudo make install # 将库拷贝到/usr/local中# 4. 生成配置文件
sudo gedit /etc/bash.bashrc # 文末添加以下内容
PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
export PKG_CONFIG_PATH# 5.向系统更新配置文件
source /etc/bash.bashrc# 6. 生成opencv.conf文件，就可以利用pkg-config链接到库了
sudo gedit /etc/ld.so.conf.d/opencv.conf # 添加库的路径： /usr/local/lib
# 7. 更新pkg-config文件
sudo ldconfig
sudo updatedb# 8.测试是否安装好了
pkg-config --modversion opencv
pkg-config --libs opencv出现以下内容，说明安装成功了！
-L/usr/local/lib -lopencv_shape -lopencv_stitching -lopencv_objdetect -lopencv_superres -lopencv_videostab -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_video -lopencv_photo -lopencv_ml -lopencv_imgproc -lopencv_flann -lopencv_core# 9. 测试程序
/home/helen/code/C++code/yolov5_zhr/main$ g++ main.cpp -o main `pkg-config --cflags --libs opencv`
/usr/bin/ld: 找不到 -lopencv_shape
/usr/bin/ld: 找不到 -lopencv_superres
/usr/bin/ld: 找不到 -lopencv_videostab
collect2: error: ld returned 1 exit status

出现的bug为没有编译contrib文件夹，重新编译contrib后再试：编译成功！

./main: error while loading shared libraries: libopencv_highgui.so.405: cannot open shared object file: No such file or directory
# 解决办法
sudo ldconfig # 更新一下库文件，因为刚刚才执行了 make install

main.cpp的代码如下： 

#include <stdio.h>
#include <opencv2/highgui.hpp>
#include <opencv2/opencv.hpp>int main(){// printf("hello world\n");cv::Mat img;img = cv::imread("/home/helen/dataset/boat/FN-frames/0a19.jpg");if(img.empty()){std::cout << "fail to read img" << std::endl;}cv::namedWindow("Image");cv::imshow("Image", img);cv::waitKey(0);return 0;
}
// g++ main.cpp -o main  编译并生成C++文件 -o是目标文件
// 执行main文件 "/home/helen/code/C++code/yolov5_zhr/"main