jquery获取上传图片的尺寸

var _URL = window.URL || window.webkitURL;$("#aieg_b_img").on("change",function(){     var files=$(this).prop('files');     var file, img;     if ((file=files[0])) {       img = new Image();       img.onload = function () {           $('#bigimg-size').text('图片尺寸为:'+this.width+"*"+this.height);       };       img.src = _URL.createObjectURL(file);     }});