piskel/js/utils/FileUtils.js

(function () {
  var ns = $.namespace('pskl.utils');

  ns.FileUtils = {
    readFile : function (file, callback) {
      var reader = new FileReader();
      reader.onload = function(event){
        callback(event.target.result);
      };
      reader.readAsDataURL(file);
    }
  };
})();