Resize image before upload

Markup Page

<div id="FileUpd1" runat="server" >
Default: <asp:FileUpload ID="ImgUpload1" runat="server" />
<asp:Button ID="Btn1" runat="server" Text="Submit " 
CssClass="btnSubmit" CausesValidation="true"/>


Code Behind - Click to read more...


Imports System.IO
Imports System.Web.UI
Imports System.Data.Sql
Imports System.Data.SqlClient
Imports System.Drawing
Imports System.Drawing.Imaging

Protected Sub Btn1_Click(ByVal sender As Object, 
              ByVal e As System.EventArgs) Handles Btn1.Click

'define variable
Dim adPhotoName As String = "PhotoNum"

'img directory - physical path
Dim saveDir As String = "\photo_repository\"
Dim appPath As String = Request.PhysicalApplicationPath

'img extensiong check
Dim ImgExt1 As String = LCase(System.IO.Path.GetExtension(ImgUpload1.FileName))
Dim ImgName1 = adPhotoName & "_1" & ImgExt1

 If (ImgUpload1.HasFile) Then
 
 'save with custom file name 
 Dim savePath As String = Path.Combine(Server.MapPath("~/photo_repository"), ImgName1)
 'save with default file name               
 'Dim savePath As String = appPath + saveDir + Server.HtmlEncode(ImgUpload1.FileName)

 'allow only jpg and gif photo files
    If (ImgExt1.ToString = ".jpg") Or 
       (ImgExt1.ToString = ".jpeg") Or 
       (ImgExt1.ToString = ".gif") Then

    'resize image before upload
      Dim image As New Bitmap(System.Drawing.Image.FromStream +
                            (ImgUpload1.PostedFile.InputStream))

     Dim width As Integer = 448   'image width
     Dim height As Integer = 336  'image height

     Using thumbnail As System.Drawing.Image = image.GetThumbnailImage + 
     (width, height, New System.Drawing.Image.GetThumbnailImageAbort + 
     (AddressOf ThumbnailCallback), IntPtr.Zero)

        Using memoryStream As New MemoryStream()
        '**default img name - use these two lines of code
        'thumbnail.Save(Server.MapPath("~/Uploaded/") + 
        'Path.GetFileName(Me.ImgUpload1.FileName), ImageFormat.Png)
        '********
        thumbnail.Save(savePath)
      End Using
   End Using
'ends here

'confirm image upload
ImgUpConf1 = ImgName1.ToString
FileUpd1.InnerHtml = + 
  "<table><tr><td><img src='../photo_repository/" +
  ImgUpConf1 & "' height='35' width='50'>" +
  "<td style='vertical-align: top;'><strong>Image 1: " + 
  ImgUpload1.FileName & "<br />" +
  "<span class='lblAdded'>Image 1 successfuly uploaded!"

Else

'alert if img fiel ext <> jpg or gif
BadImgFormat = ImgExt1.ToString
ImgName1 = NoImage      'db photo record
FileUpd1.InnerHtml = +
  "<table><tr><td><img src='../photo_repository/no_image.jpg' " + 
  "height='35' width='50'/>" +
  "<td style='vertical-align: top;' ><span style='color: red;'>" +
  "ERROR: The default image format is " & BadImgFormat & "!<br />" +
  "Only .jpg and .gif file type allowed.<br /><a href='ad_photo.aspx?img=1'" +
  "class='colorbox2'>Try again."

  End If
 End Sub

'define function   
 Public Function ThumbnailCallback() As Boolean
        Return False
    End Function
End Class