How to get json file object and upload it in laravel

I want to upload an json file object in laravel , this object come from angular js with the below format:

{
      "key": "lfobj2399fe3b",
      "lfFile": {},
      "lfFileName": "photo-1433354359170-23a4ae7338c6.jpg",
      "lfDataUrl": "blob:http://localhost/14044b8b-9dcb-4461-8e2e-cf5337611396",
      "element": {
        "0": {
          "ng339": 198
        },
        "length": 1
      }
    } 

This is the plugin i've used to implement file upload in angular js : https://github.com/shuyu/angular-material-fileinput

I've tried :

if ($request->hasFile('banners')) {
                return \Response::json('file available',$statusCode);
            }

to check if any file is available in my input but i got nothing. if i want to get this object as an object i get it's value by using :

            $banners = $request->input('banners');

but i can't upload any file with this input. how can i get this object and upload it in laravel ?