title: Finding the area of the black spots in a circle MATLAB
body: <p>Is it possible to find the area of the black pixelation of an area within a circle? in other words I want to find the number of pixels (the area) of the RGB 0,0,0 (black pixels) within the circle. I do not want the areas of the white pixels (1,1,1) within the circle. I also have a radius of the circle if that helps. Here is the image:</p>
  
  <p><img src="https://i.stack.imgur.com/8KSwF.jpg" alt="enter image description here"></p>
  
  <p>Here is the code:</p>
  
  <pre><code>BW2= H(:,:) &lt;0.45 ;%&amp; V(:,:)&lt;0.1;
  aa=strel('disk',5);
  
  closeBW = imclose(BW2,aa);
  figure, imshow(closeBW)
  imshow(closeBW)
  viscircles([MYY1 MYX1], round(MYR2/2))
  </code></pre>
  
  <p>MYY1,MYX2, and the other values are calculated by my program. How can I find the area of the black pixelation in my circle?</p>