Dim quelle As System.Drawing.Image
        Dim inp As New IntPtr
        Dim Thumb As System.Drawing.Image
 
        quelle = System.Drawing.Image.FromFile("c:\test.jpg")
        Thumb = quelle.GetThumbnailImage(640, 480, Nothing, inp)
 
        Dim Format As System.Drawing.Imaging.ImageFormat
 
        Thumb.Save("c:\thumb.jpg", Format.Jpeg)