Exception: "URI formats are not supported"

Try This

ImagePath = "http://localhost/profilepics/abc.png";
   HttpWebRequest request = (HttpWebRequest)WebRequest.Create(ImagePath);
          HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream receiveStream = response.GetResponseStream();

string uriPath =
    "file:\\C:\\Users\\john\\documents\\visual studio 2010\\Projects\\proj";
string localPath = new Uri(uriPath).LocalPath;