scrollWidth of perspective image

scrollWidth of perspective image

I'm trying to find out the largest width of an image (including parts clipped by surrounding div) that has perspective css applied to it, such as this:  
  1. -webkit-transform:perspective(50em) rotateX(60deg);
I'm gotten to this point, but I'm stuck.  It appears to be giving me the width measured along the x-axis in the center of the skewed image, but I need to know the widest width which is at the bottom of the skewed image :

  1. $(document).ready(function() {
  2.   $('img').each(function() {
  3.     $(this).load(function() {  // using load function to ensure images are loaded first
  4.       var pimg = $(this)[0].scrollWidth;
  5.       console.log('Perspective size: ' + pimg);
  6.     });
  7.   });
  8. });

Is it possible to get the widest perspective width ?