title: Edge removal (in matlab)
body: <p>I have a image which looks like this:</p>
  
  <p><img src="https://i.stack.imgur.com/hJjIQ.png" alt="enter image description here"></p>
  
  <p>The (blue) background have the value zero, the the (red) ring has a "large" value (compared to the rest of the image). I want to plot only the orange part of the sample. However, due to the finite resolution of the image the edges still appear as show here:</p>
  
  <p><img src="https://i.stack.imgur.com/YmXPn.png" alt="enter image description here"></p>
  
  <p>As you can see specially the white regions (yes there are a few) above are hard to see due to all the noise from edges.</p>
  
  <p>Is there a good algorithm (preferable in matlab) which can help me clean up these images?</p>