This is a linker issue. Try:
g++ -o test_1 test_1.cpp ` pkg-config opencv --cflags --libs`
after compiling libraries from source, you need to do finally:
sudo ldconfig
test.cpp:(.text+0xc0): undefined reference to `cv::imread(std::string const&, int)'
原文:https://www.cnblogs.com/sddai/p/10364350.html