title: Marking an interest point in an image using c++
body: <p>I have a bitmap image like this</p>
  
  <p><img src="https://i.stack.imgur.com/xEIbk.png" alt="enter image description here">
  My requirement is to create a GUI to load the image and for changing the contrast and other things on the image and algorithm to mark the particular area in silver colour as shown in the fig using C++ or C#.I am new to image processing and through my search I have found out that I can use the Histogram of the image for finding the required area.These are the steps.</p>
  
  <ul>
  <li>Get the histogram</li>
  <li>Search for intensity difference</li>
  <li>Search for break in the line</li>
  </ul>
  
  <p>Can someone suggest me how can I proceed from here.Can I use Opencv for this or any other efficient methods are available..?</p>
  
  <p>NOTE:</p>
  
  <p><img src="https://i.stack.imgur.com/nXQ04.png" alt="enter image description here"> This image have many bright points and the blob algorithm is not successful.
  Any other suggestions to retrieve the correct coordinates of the rectangle like object.</p>
  
  <p>Thanks </p>