Closed Unassigned: Error converting value "System.Drawing.Bitmap" to type 'System.Drawing.Bitmap' [24549]

Json.Net (test with 4.5 and 5 version) wrong serialize Bitmap object:

"Photo": {
"viewMap": {},
"ImageBitmap": "System.Drawing.Bitmap",
"FileName": "1",
"Extension": "jpg",
"Category": "employee",
"Id": 1
},

The field ImageBitmap is System.Drawing.Bitmap and not the value in Base64, why?
Comments: It's not a byte[]