Private Function EncoderInfo _
        (ByVal FormatDescriptor As String) As Imaging.ImageCodecInfo
 
        ' Formatdescriptoren: BMP JPEG GIF TIFF PNG
 
   Dim i As Integer = 0
 
   Dim encoders() As Drawing.Imaging.ImageCodecInfo = _
   Imaging.ImageCodecInfo.GetImageEncoders()
   FormatDescriptor = Trim(UCase(FormatDescriptor))
 
   While i < encoders.Length
      If UCase(encoders(i).FormatDescription) = FormatDescriptor Then
         Return encoders(i)
      End If
      i += 1
   End While
   Return Nothing
End Function
 
 
Private Function LockBits(ByVal bmp As Bitmap, _
                       ByRef bmp_data As Imaging.BitmapData, _
                       ByRef bmp_array() As Byte) As IntPtr
 
   ' Rectangle für die Größe des gesamten geladenen Bildes erstellen 
   Dim bmp_rect As New Drawing.Rectangle(0, 0, bmp.Width, bmp.Height)
 
   ' Bilddaten im Speicher sperren
   bmp_data = bmp.LockBits _
    (bmp_rect, Imaging.ImageLockMode.ReadWrite, bmp.PixelFormat)
 
   ' Adresse des Beginns der Bitmap-Bilddaten ermitteln
   Dim bmp_ptr As IntPtr = bmp_data.Scan0
 
   ' Array für Bitmapdaten in geeigneter Größe erstellen 
   ' (8-Bit-Bitmap: 1 Byte / Pixel)
   Dim bmp_bytes As Integer = bmp_data.Stride * bmp.Height
 
   ' Null-basiertes Byte-Array in der erforderlichen Größe vereinbaren
   ReDim bmp_array(0 To bmp_bytes - 1)
 
   Return bmp_data.Scan0
End Function