error while loading shared libraries: libopencv_core.so.3.0: cannot open shared object file: No such file or directory.
I am using eclipse c/c++ ide on ubuntu 14.04. Tried everything which I got from google 



You are trying to run in Eclipse so the solution provided (The export part) in openCV program compile error "libopencv_core.so.2.4: cannot open shared object file: No such file or directory" in ubuntu 12.04 May not work. I suppose you have installed open cv following the instructions provided in open cv documentation. If so, you can get rid of this problem by adding the following environment variables to the eclipse runtime.
Name - LD_LIBRARY_PATH
Value - $LD_LIBRARY_PATH:/usr/local/lib
Steps
On the window on the right hand side you see the Environment tab.
Here click on New, you'll see a New Environment Variable pop up.

rapthoption Use -rpath option. In Eclipse CDT, right click on "DisplayImage" project -> Properties -> C/C++ Build -> Settings -> Tool Settings -> C Linker -> Miscellaneous -> Other options and Add `-rpath "path to libopencv_core.so.3.0" or easier set LD_LIBRARY_PATH=path to so folder - kiranpradeep