title: Height and width of object using camera in iOS
body: <p>I am working on a small education demo which should measure height and width of the object using iOS camera.</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>I have a new theory to measure the width of an object.</p>
  
  <p><img src="https://i.stack.imgur.com/M0Oym.jpg" alt="enter image description here"></p>
  
  <p>In above image, if i can get Angle α and Angle ß, i can get width of the unknown side by using trigonometry formulas. I have the values of b1 and b2 already.</p>
  
  <p><strong>OLD:</strong></p>
  
  <p>Right now, i am focusing on measuring length only.
  As per my knowledge it should be 3 step process.</p>
  
  <ol>
  <li>User snaps one end of the object.</li>
  <li>User snaps other end of the object.</li>
  <li>User snaps center of the object. (Suggest me a better way for these please)</li>
  </ol>
  
  <p>I get the approximate measurements using above process, but for the 3rd step, in which user snaps the center of the object. I want to show pointer location on screen (as camera overlay) to help user determine the center of the object.</p>
  
  <p>This is how i am doing it right now.
  <img src="https://i.stack.imgur.com/PzdpW.png" alt="enter image description here"></p>
  
  <p>How can i draw pointer location for 3rd step?</p>
  
  <p>Note: Please suggest alternative/best way to make it possible. I would love another suggestions. Thanks.!!</p>