title: cvNamedWindow - function not implemented, unable to launch LibHand
body: <p>I'd like to use the LibHand hand gesture library, but I'm unable to launch it on Ubuntu 13.10.</p>
  
  <p>I've compiled it successfully (after overcoming few issues related to the linker), but when running pose_designer, the OpenCV library logs that GUI support function is not implemented, instructing me to install libgtk2.0-dev and pkg-config. However, after the installation of these packages and rebuilding the OpenCV library, the issue persists. Inspired by the SO posts of people with comparable OpenCV problems (<a href="https://stackoverflow.com/questions/14655969/opencv-error-the-function-is-not-implemented">OpenCV error: the function is not implemented</a>), I switched to libqt. Unfortunately, the issue persists.</p>
  
  <p>An extract from the log file is attached below. What could be the reason for this error?</p>
  
  <pre><code>WARNING: the mesh 'hand.mesh' includes vertices with more than 4 bone
    assignments. The lowest weighted assignments beyond this limit have been
    removed, so your animation may look slightly different. To eliminate this,
    reduce the number of bone assignments per vertex on your mesh to 4.
  OpenCV Error: Unspecified error (The function is not implemented. Rebuild
    the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu
    or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure
    script) in cvNamedWindow, file /home/user/Downloads/opencv-2.4.8/modules/highgui
    /src/window.cpp, line 483
  Exception: /home/user/Downloads/opencv-2.4.8/modules/highgui/src/window.cpp:483:
    error: (-2) The function is not implemented. Rebuild the library with Windows,
    GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install
    libgtk2.0-dev and pkg-config, then re-run cmake or configure script
    in function cvNamedWindow
  </code></pre>