使条形码变大Itextsharp VB.net

Question

这是我用来制作条形码的代码，但是我无法将其放大，有什么想法吗？

    Private Sub BarcodeGen()

    Dim Code39 As Barcode39 = New Barcode39()
    Code39.Code = TextBox.Text
    Code39.Size = 80.0F
    Code39.StartStopText = False
    Code39.GenerateChecksum = False
    Code39.Extended = False
    Dim Mem As MemoryStream = New MemoryStream()
    Code39.CreateDrawingImage(System.Drawing.Color.Black, System.Drawing.Color.White).Save("D:\BC.png")

End Sub

这是生成的条形码