只要调用这句：var result = client.Accurate(image); 就会报错

WebException: Error writing request: The authentication or decryption has failed.

System.Net.WebConnectionStream.WriteHeaders ()

System.Net.WebConnectionStream.SetHeaders (System.Byte[] buffer)

(wrapper remoting-invoke-with-check) System.Net.WebConnectionStream:SetHeaders (byte[])

System.Net.HttpWebRequest.SendRequestHeaders (Boolean propagate_error)