title: Python OpenCV imshow() function is not implemented
body: <p>I started to use opencv in Python. but I have some problem with that.
  here is my code:</p>
  <pre><code>image = None
  image = cv2.imread('7.jpg')
  if image != None:
      print(&quot;len &gt;    &quot; + str(len(image)))
      # show image
      cv2.imshow('image', image)
      cv2.waitKey(0)
      cv2.destroyAllWindows()
  else:
      print(&quot;Image is None&quot;)
  </code></pre>
  <p>when I run this simple code I have this error:</p>
  <blockquote>
  <p>OpenCV Error: Unspecified error (The function is not implemented.</p>
  <p>If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function cvShowImage</p>
  </blockquote>
  <p>I checked that, but all the packages are installed. I remove them and retry to install. but that didn't work!!!
  what should I do...</p>
  <p>I actually checked this <a href="https://stackoverflow.com/questions/14655969/opencv-error-the-function-is-not-implemented">Link</a></p>
  <p>but when I try this command: <code>cmake -D WITH_QT=ON ..</code> I have this in terminal:</p>
  <blockquote>
  <p>The source directory &quot;/home&quot; does not appear to contain CMakeLists.txt</p>
  </blockquote>
  <p>what should I do?</p>