title: Identify darkest color that occurs noncontigously in an image
body: <p>I am looking for a way to identify the dark grey ovals on this example image:</p>
  <p><img src="https://i.stack.imgur.com/KtzM7.png" alt="enter image description here" /></p>
  <p>I know I can find the darkest color in the image with a simple <code>min</code>. However, I am not interested in identifying the black in this example (darkest, contiguous part of the image). Therefore, I think my problem can be described: identifying the darkest color in the image that occurs <em>noncontigously</em>. That is, the dark grey ovals in the example above. I would appreciate your help. Notice how there's some noise also in the image, that I would ideally not take into account when find this darkest noncontiguous color. However, that might be different step/too much for this question.</p>
  <p>I've been messing with output from <code>regionprops</code> to achieve this goal. However, I am not sure how to combine that output with color data. I was wondering if there is some MATLAB tool, or some image processing trick that would make this task easier.</p>
  <p>Thanks in adavnce!</p>