download image by client object Model : The remote server returned an error: (404) Not Found

Hello,

•  I have an image in the following path in SharePoint

            http://servername/sites/Test/en-us/PublishingImages/activity.png

• I write the following code to download image by client object Model :

           ClientContext clientContext = new ClientContext("http://ServerName/sites/Test");
           DownloadFile(clientContext, "/en-us/PublishingImages/", @"C:\Test", "activity.png");           

           public static bool DownloadFile(ClientContext context, string fileRelativeUrl, string destinationPath, string fileName)
            {
                fileRelativeUrl = fileRelativeUrl.Replace("/Images/", "/PublishingImages/");
                string sourceUrl = fileRelativeUrl + fileName;
                string completeDestinationPath = destinationPath + fileName;

                if (!System.IO.File.Exists(completeDestinationPath))
                {
                    Directory.CreateDirectory(destinationPath);
                    FileInformation spFileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(context, sourceUrl);

                    using (Stream destination = System.IO.File.Create(completeDestinationPath))
                    {
                        for (int a = spFileInfo.Stream.ReadByte(); a != -1; a = spFileInfo.Stream.ReadByte())
                            destination.WriteByte((byte)a);
                    }
                }
           }

• When I run the code Th get the following error "The remote server returned an error: (404) Not Found."

      at this line "FileInformation spFileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(context, sourceUrl);"

    How Can I solve this error ?

    Thanks

ASk