title: detecting dots in image- opencv python
body: <p>I have an image from a Petri dish that I want to detect black round dots (number and location), preferably in python+opencv.
  I tried different methods in python opencv, but no success, e.g. hough circle, findContours, etc.</p>
  <p>I used <a href="https://stackoverflow.com/questions/48154642/how-to-count-number-of-dots-in-an-image-using-python-and-opencv">How to count number of dots in an image using python and Opencv?</a> and <a href="https://stackoverflow.com/questions/44439555/count-colored-dots-in-image/44443494">count colored dots in image</a>. The problem for both methods is that they also detect the right section also as dots (outside from the dish). Therefore the number of detected dots are very high~2K
  <a href="https://i.stack.imgur.com/I77wv.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/I77wv.jpg" alt="enter image description here" /></a>
  <a href="https://i.stack.imgur.com/cAYIv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cAYIv.png" alt="input" /></a></p>
  <p>desired output:
  <a href="https://i.stack.imgur.com/evY7S.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/evY7S.png" alt="desired output" /></a></p>