Checks the size of all images on page to ensure they are the same as the dimensions of the image file

Imagesize.js

[].slice.call(document.getElementsByTagName('img')).map(function(i) {
 var src = i.src, i2 = new Image();
 i2.src = src
 return {
  src: src,
  i1: i,
  i2: i2
 }
}).filter(function(i) {
 return !(i.i1.width === i.i2.width || i.i1.height === i.i2.height)
}).map(function(i) {
 return i.i1.alt + ': ' + /^.*\/([^\/]*)$/.exec(i.src)[1] + ", width: " + i.i2.width + ", height: " + i.i2.height
}).join('\n')