Package opencv was not found in the pkg-config search path. Perhaps you should add the directory con

使用pkg-config和opencv时报错

Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing `opencv.pc’
to the PKG_CONFIG_PATH environment variable

1. List item

方法一，按照错误信息，执行命令

export PKG_CONFIG_PATH=/your/path:$PKG_CONFIG_PATH

再查看一下

echo $PKG_CONFIG_PATH

/your/path指的是，安装路径中含有opencv4.pc或者opencv.pc的文件夹路径

方法二，把opencv4.pc文件添加到，pkg-config的搜索路径中，执行

 find / -name pkgconfig

找到如下路径，
/usr/share/pkgconfig
/usr/lib/pkgconfig
/usr/lib/x86_64-linux-gnu/pkgconfig
选择一个即可

然后把.pc文件复制到选择的文件夹中
例如选择/usr/lib/pkgconfig
sudo cp /opt/opencv4.5.5/lib/pkgconfig/opencv4.pc /usr/lib/pkgconfig