title: Is the colormap conversion of openCV linear?
body: <p>I have a gray scale image (i.e. 1 channel). I am using the opencv function applyColorMap() to improve the visualization. For example, if I have the code below</p>
  
  <pre><code>applyColorMap(imgGray, imgOut, COLORMAP_RAINBOW);
  </code></pre>
  
  <p>Somebody does know if the colormap conversion is linear?</p>
  
  <p><img src="https://i.stack.imgur.com/AHbE5.png" alt="enter image description here"></p>
  
  <p><a href="https://i.stack.imgur.com/KimYy.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KimYy.jpg" alt="image description"></a><br>
  <sub>(source: <a href="http://docs.opencv.org/trunk/_images/colorscale_rainbow.jpg" rel="nofollow noreferrer">opencv.org</a>)</sub>  </p>