title: Difference between adaptive thresholding and normal thresholding in opencv
body: <p>I have this gray video stream:
  <img src="https://i.stack.imgur.com/c5yTh.png" alt="enter image description here"></p>
  
  <p>The histogram of this image:</p>
  
  <p><img src="https://i.stack.imgur.com/1CkG3.png" alt="enter image description here"></p>
  
  <p>The thresholded image by :</p>
  
  <pre><code>  threshold( image, image, 150, 255, CV_THRESH_BINARY );
  </code></pre>
  
  <p>i get :</p>
  
  <p><img src="https://i.stack.imgur.com/umDwa.png" alt="enter image description here"></p>
  
  <p>Which i expect.</p>
  
  <p>When i do adaptive thresholding with :</p>
  
  <pre><code>adaptiveThreshold(image, image,255,ADAPTIVE_THRESH_GAUSSIAN_C, CV_THRESH_BINARY,15,-5);
  </code></pre>
  
  <p>i get :</p>
  
  <p><img src="https://i.stack.imgur.com/cMjK9.png" alt="enter image description here"></p>
  
  <p>Which looks like edge detection and not thresholding. What i expected was black and white areas . So my question is, why does this look like edge detection and not thresholding.</p>
  
  <p>thx in advance</p>