var imageData = function(files) {

  var imgWidth  = 0,

      imgHeight = 0;

​

  var reader  = new FileReader();

​

  reader.addEventListener('load',function(theFile) {

    var img = new Image();

    img.src = theFile.target.result;

​

    img.addEventListener('load',function(){

​

      return {

        imgWidth  :this.width,

        imgHeight :this.height  

      };

    });

​

  });

​

  reader.readAsDataURL(files);

};

​

function checkImg() {

  var files = imgs.files;

  for (var i = 0; i < files.length; i++){

    console.log(imageData(files[i]).imgWidth);

  }

}

​

var imgs = document.getElementById('img');

​

imgs.addEventListener('change',checkImg);