Dim vorschau, vorschau1 as Bitmap
vorschau = CType(Bitmap.FromFile(tempfile), Bitmap)
vorschau1 = New Bitmap(vorschau.Width, vorschau.Height)
vorschau1.SetResolution(300, 300)
Using g As Graphics = Graphics.FromImage(vorschau1)
   g.DrawImage(vorschau, 0, 0, vorschau.Width, vorschau.Height)
End Using
vorschau1.Save("Abcd.jpg",Imaging.ImageFormat.Jpeg)
vorschau.Dispose()
vorschau1.Dispose()

Dont debug, because there will allways be one more bug