Package opencv was not found (CentOs 6.5)

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

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                                                              
No package 'opencv' found

Solution
1) find opencv.pc
$ locate opencv.pc

/mnt/vol3/installers/opencv/opencv-2.4.8/build/unix-install/opencv.pc      
...    
/usr/local/lib/pkgconfig/opencv.pc  

2) then add to enviroment variable the path
$ export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig/