这是一个链接器问题。尝试：

This is a linker issue. Try:

g++ -o test_1 test_1.cpp `pkg-config opencv --cflags --libs`

这应该可以编译源代码。但是，如果您最近从源编译OpenCV，您将在运行时遇到链接问题，将不会找到库。
在大多数情况下，在从源代码编译库之后，您需要最后执行：

This should work to compile the source. However, if you recently compiled OpenCV from source, you will meet linking issue in run-time, the library will not be found. In most cases, after compiling libraries from source, you need to do finally:

sudo ldconfig