title: Is there any example of cv2.KalmanFilter implementation?
body: <p>I'm trying to build a veeery simple tracker for 2D objects using python wrapper for OpenCV (cv2). </p>
  
  <p>I've only noticed 3 functions:</p>
  
  <ul>
  <li>KalmanFilter (constructor)</li>
  <li>.predict()</li>
  <li>.correct(measurement)</li>
  </ul>
  
  <p>My idea is to create a code to check if kalman is working like this:</p>
  
  <pre><code>kf = cv2.KalmanFilter(...)
  # set initial position
  
  cv2.predict()
  corrected_position = cv2.correct([measurement_x, measurement_y])
  </code></pre>
  
  <p>I've found some examples using the cv wrapper but not the cv2...</p>
  
  <p>Thanks in advance!</p>