title: Compiling opencv samples: unknown cmake command ocv_check_dependencies
body: <p>I am trying to build the OpenCV samples which come with the source package and I get the following:</p>
  
  <pre><code>CMake Error at CMakeLists.txt:10 (ocv_check_dependencies):
    Unknown CMake command "ocv_check_dependencies".
  </code></pre>
  
  <p>I did install OpenCV using</p>
  
  <pre><code>cmake .
  make
  sudo make install
  </code></pre>
  
  <p>and I got a tutorial snippet working (thus I suppose it is installed correctly as a library). However, compiling the samples does not work.</p>
  
  <p>I guess I have to somehow configure CMake to have “ocv_check_dependencies” - but how? I am lost!</p>