title: How can we adjust levels in HTML5 Canvas?
body: <p>I've a psd file and I was to create an image in canvas similar to the one in psd.
  One of the filters applied to the image in Photoshop is "Levels".</p>
  
  <p>I'm using Canvas image manipulation library - CamanJS.</p>
  
  <p>Based on my finding, Levels in Photoshop is color correction in canvas but I don't see any api for that in CamanJS.</p>
  
  <p>Any idea if we can do this?
  I'm open to any other library if it makes this task easier.</p>
  
  <p>Thanks in advance.</p>