title: Best value for threshold in Canny
body: <p>I have an image which I want to detect edges on that. I found Canny has been used a lot ( I don't know whether I have a better option than that). I have set the values as follow:</p>
  
  <pre><code>  Imgproc.Canny(img, img, 10, 100, 3,true)
  </code></pre>
  
  <p>I've changed threshold values but don't see that much of a change in my image. Can anyone explain to me if there is a logical way to figure out numbers for threshold values (my image is gray scale)</p>
  
  <p>Thank you...</p>