Type undefined reference to `cv::fastFree(void*)'

Question

I started the tutorial for opencv 2.4.7 on Win8, latest MinGW, and Eclipse Kepler R1, CDT. C++ Compiler includes are referencing to [path-to-opencv]\\open247\\build\\include

Answer 1

Have you link correctly your library?

-lopencv_core
-lopencv_highgui
-L<opencv_library_path>

The libraries have to be specified after the source file on the compiler/linker command line. (The linker keeps track of unresolved symbols, and resolves them via later command-line arguments.)