Size of Image

sizeof.js

function sizeOf(url, callback) {
          var image = new Image();
          image.src = url;
          image.onload = function () {
            callback && callback(null, {width: image.width, height: image.height, ratio: image.width/image.height, img: image})
          }
          image.onerror = function(){
            callback && callback('error')
          }
        }