public void PrintImage(Bitmap bitmap) { if (websocket != null) { PrintImageRequestMessage message = new PrintImageRequestMessage(); PrintImage pi = new PrintImage(); MemoryStream ms = new MemoryStream(); bitmap.Save(ms, ImageFormat.Png); byte[] imgBytes = ms.ToArray(); string base64Image = Convert.ToBase64String(imgBytes); pi.Bitmap = base64Image; // serialize image to string.. message.payload = pi; websocket.Send(JsonUtils.serialize(message)); } }