protected Stream GetStream(String gazouUrl)
{
    Stream rtn = null;
    HttpWebRequest aRequest = (HttpWebRequest)WebRequest.Create(gazouUrl);
    HttpWebResponse aResponse = (HttpWebResponse)aRequest.GetResponse();

    using (StreamReader sReader = new StreamReader(aResponse.GetResponseStream(), System.Text.Encoding.Default))
    {
        rtn = sReader.BaseStream;
    }
    return rtn;
}

private static MemoryStream GetStreamFromUrl(string url)
{
    byte[] imageData = null;

    using (var wc = new System.Net.WebClient())
        imageData = wc.DownloadData(url);

    return new MemoryStream(imageData);
}