WCF transferMode=Streamed, the output Stream will be serialized?

Question

From this article I prepare a test project.

WCF service side:

web.config like this:

<bindings>
<basicHttpBinding>
  <binding name="HttpStreaming" maxReceivedMessageSize="67108864"
           transferMode="Streamed"/>
</basicHttpBinding>
<!-- an example customBinding using Http and streaming-->
  <netTcpBinding>
    <binding name="netTcpBindConfig"  closeTimeout="00:30:00" portSharingEnabled="true"
            openTimeout="00:30:00" receiveTimeout="00:30:00" sendTimeout="00:30:00" maxBufferPoolSize="2147483647" maxBufferSize="2147483647" maxReceivedMessageSize="2147483647"
            transactionFlow="false" transferMode="Buffered" transactionProtocol="OleTransactions"  maxConnections="50"
            hostNameComparisonMode="StrongWildcard" listenBacklog="100">

      <readerQuotas maxDepth="2147483647"
                                maxStringContentLength="2147483647"
                                maxArrayLength="2147483647"
                                maxBytesPerRead="2147483647"
                                maxNameTableCharCount="2147483647" />
      <reliableSession ordered="true"  inactivityTimeout="00:01:00" enabled="false" />
      <security mode="None">
        <transport clientCredentialType="None" protectionLevel="None"  />
        <message clientCredentialType="None"  />
      </security>
    </binding>
  </netTcpBinding>  
</bindings>

service.cs code is like this:

public Stream GetStream(string data)
        {
            //this file path assumes the image is in
            // the Service folder and the service is executing
            // in service/bin 



            string filePath = Path.Combine(
                System.Environment.CurrentDirectory,
                "D:\\Practice\\WcfStream\\WcfStream\\image.jpg");
            //open the file, this could throw an exception 
            //(e.g. if the file is not found)
            //having includeExceptionDetailInFaults="True" in config 
            // would cause this exception to be returned to the client
            try
            {
                FileStream imageFile = File.OpenRead(filePath);
                return imageFile;
            }
            catch (IOException ex)
            {
                Console.WriteLine(
                    String.Format("An exception was thrown while trying to open file {0}", filePath));
                Console.WriteLine("Exception is: ");
                Console.WriteLine(ex.ToString());
                throw ex;
            }
        }

Client code is like this:

private void Button_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                ServiceReference1.StreamingSampleClient c = new ServiceReference1.StreamingSampleClient("NetTcpBinding_IStreamingSample");// I use the basic http binding and net tcp binding to do testing.
                Stream s = c.GetStream("aa");

                Img.Source = BitmapFrame.Create(s,
                                                  BitmapCreateOptions.None,
                                                  BitmapCacheOption.OnLoad);

                c.Close();

            }
            catch (Exception e1)
            {
                MessageBox.Show(e1.Message, "Error");
            }
            finally
            {

            }
        }

the client app.config is like this:

<bindings>
            <basicHttpBinding>
                <binding name="BasicHttpBinding_IStreamingSample" closeTimeout="00:01:00"
                    openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
                    allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
                    maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="2147483647"
                    messageEncoding="Text" textEncoding="utf-8" transferMode="Streamed"
                    useDefaultWebProxy="true">
                    <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
                        maxBytesPerRead="4096" maxNameTableCharCount="16384" />
                    <security mode="None">
                        <transport clientCredentialType="None" proxyCredentialType="None"
                            realm="" />
                        <message clientCredentialType="UserName" algorithmSuite="Default" />
                    </security>
                </binding>
            </basicHttpBinding>
            <netTcpBinding>
                <binding name="NetTcpBinding_IStreamingSample" closeTimeout="00:01:00"
                    openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
                    transactionFlow="false" transferMode="Streamed" transactionProtocol="OleTransactions"
                    hostNameComparisonMode="StrongWildcard" listenBacklog="10" maxReceivedMessageSize="2147483647"
                    maxBufferPoolSize="524288" maxBufferSize="65536" maxConnections="10"
                    >
                    <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
                        maxBytesPerRead="4096" maxNameTableCharCount="16384" />
                    <reliableSession ordered="true" inactivityTimeout="00:10:00"
                        enabled="false" />
                    <security mode="None">
                        <transport clientCredentialType="Windows" protectionLevel="EncryptAndSign" />
                        <message clientCredentialType="Windows" />
                    </security>
                </binding>
            </netTcpBinding>
        </bindings>

I use the basic http binding and net tcp binding to do testing. And use WireShark to capture the network traffic, I found that when I use the http binding on clinet, the stream will be convert to a base64 string in the xml respose. It indicate that the stream was serialized to xml. But when I use net tcp binding on client, I am not sure the Data was serialized or not. because from the WireShark I can't figure out the data is serialized or not.