title: How to drag only one corner of an image view in iOS
body: <p>I try to implement one feature of a photo editing app.I do not have any clue to implement this that's why I share some photo to explain my question.the normal picture looks like this.</p>
  
  <p><a href="https://i.stack.imgur.com/HY7Kv.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/HY7Kv.jpg" alt="enter image description here"></a>
  when I click the lower right corner of the image and dragging it down it only expand that part and the new image looks like this.</p>
  
  <p><a href="https://i.stack.imgur.com/rDYTL.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rDYTL.jpg" alt="enter image description here"></a></p>
  
  <p>And if I do the reverse the picture look like this.</p>
  
  <p><a href="https://i.stack.imgur.com/NQXlZ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NQXlZ.jpg" alt="enter image description here"></a></p>
  
  <p>so the question is which gesture actually support this kind of dragging and how to implement this? For batter understanding you can see <a href="https://itunes.apple.com/us/app/manly-photo-editor-for-men/id1263326810?mt=8" rel="nofollow noreferrer">manly</a> app which implement this in there abs section.</p>