title: Selection of window size in Adaptive thresholding
body: <p>I need to segment characters from following License plates (single row license plate and double row license plate)
  using <code>cvAdaptiveThreshold()</code>. Which is the best <code>window size</code> for doing adaptive threshold
  in first image and in second image. </p>
  
  <pre><code>How is window size for adaptive threshold is determined ??
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/pS6u2.jpg" alt="Image 1"></p>
  
  <p><img src="https://i.stack.imgur.com/KzLjX.jpg" alt="Image 2"></p>