title: BackgroundSubtractorMOG2 is very noise?
body: <p>I'm using <code>BackgroundSubtractorMOG2</code> as code below</p>
  
  <pre><code>BackgroundSubtractorMOG2 bgr;
  double learningRate = 0.05;
  (bgr)(img_input, img_mask, learningRate);
  </code></pre>
  
  <p>But the result is not good, there are many noise foreground pixels here (figure below)
  <img src="https://i.stack.imgur.com/Lkm1W.png" alt="enter image description here"></p>
  
  <p>When I use BackgroundSubtractorMOG as code below</p>
  
  <pre><code>BackgroundSubtractorMOG bgr(81, 3, 0.1);
  double learningRate = 0.05;
  (bgr)(img_input, img_mask, learningRate);
  </code></pre>
  
  <p>The result is better, but this method is slower (figure below) 
  <img src="https://i.stack.imgur.com/Fg2ra.png" alt="enter image description here"></p>
  
  <p>I want to use BackgroundSubtractorMOG2 because it is faster, but the result is very noise.</p>
  
  <p>Someone can show me the correctly way to use BackgroundSubtractorMOG2?</p>
  
  <p>Thank you!</p>
  
  <p>T&amp;T</p>