title: iPhone Objective C: UIImage - Region of Interest
body: <p>Is there any way to get the min rectangle area which contains all the non-transparent part of an UIImage?</p>
  
  <p>Reading pixel by pixel to check where alpha == 0 ...isn't a good way I believe. </p>
  
  <p>Any better way?</p>
  
  <p>Many thanks for reading</p>