title: how to detect black spots and draw over them?
body: <p>I'm developing android application and on my layout I have one image with black spots(dots) and now I want to detect this black spots and draw buttons over them and make buttons clickable. How can i detect this black spots(dots) and draw them programatically in Java(not Kotlin)?</p>
  
  <p>Here is the example of one image. Thank you very much!
  <a href="https://i.stack.imgur.com/AsORr.png" rel="nofollow noreferrer">Click here to view example of one image with black spots</a></p>
  
  <p>P.S. I don't want to use external libraries. </p>