What is the difference of these two parameters in Background Subtraction OpenCV
<p>I using OpenCV for foreground detection, but I have a question if someone can help.
The question is in these two parameters:</p>

<ul>
<li><strong>Learn Rate</strong> in: <code>bst.apply(currentFame, foregroungMask, learnRate); // -1 for auto, and the range is 0~1</code></li>
<li><strong>Ratio</strong> <code>bst.setBackgroundRatio(double ratio) // default is 0.8xxx</code></li>
</ul>

<p>The question is are these two parameters are the same, if the answer is the <strong>NO</strong> then what is the second parameter can do?</p>

<p>The question has come when I saw that <code>setBackgroundRatio(double ratio)</code> method is not present in <code>BackgroundSubtractorKNN</code> class, but it is only in <code>BackgroundSubtractorMOG2</code> class. But they both have the <em>learn rate</em> parameter in <code>apply()</code> method.</p>

<p><strong>Note:</strong> I am using OpenCV in Java</p>