title: OpenCV: "libopencv_core.so.2.3: cannot open shared object file: No such file or directory"
body: <p>I've just installed OpenCV on my Debian machine, and I'm having issues with it. I followed the install guide on the Wiki. Trying to compile the examples gives what appears to be a successful compile, however trying to run them ends up throwing an error:</p>
  
  <pre><code>fagg@hubble:~/src/OpenCV-2.3.1/samples/cpp$ g++ -Wall em.cpp
  -lopencv_core -lopencv_imgproc -lopencv_calib3d -lopencv_video
  -lopencv_features2d -lopencv_ml -lopencv_highgui -lopencv_objdetect
  -lopencv_contrib -lopencv_legacy
  fagg@hubble:~/src/OpenCV-2.3.1/samples/cpp$ ./a.out
  ./a.out: error while loading shared libraries: libopencv_core.so.2.3:
  cannot open shared object file: No such file or directory
  fagg@hubble:~/src/OpenCV-2.3.1/samples/cpp$ pkg-config opencv
  --libs-L/usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui
  -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d
  -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann
  fagg@hubble:~/src/OpenCV-2.3.1/samples/cpp$
  </code></pre>
  
  <p>But even doing this doesn't work:</p>
  
  <pre><code>fagg@hubble:~/src/OpenCV-2.3.1/samples/cpp$ g++ -Wall em.cpp
  `pkg-config opencv --cflags --libs`
  fagg@hubble:~/src/OpenCV-2.3.1/samples/cpp$ ./a.out
  ./a.out: error while loading shared libraries: libopencv_core.so.2.3:
  cannot open shared object file: No such file or directory
  fagg@hubble:~/src/OpenCV-2.3.1/samples/cpp$
  </code></pre>
  
  <p>I think there's an issue with the linking, but I'm not quite sure what's going on. This is a completely fresh install of OpenCV - I've never had it on this machine before. Does anyone have any ideas?</p>