Dim b As Bitmap = New Bitmap(pbLupe.Width, pbLupe.Height)
        Dim i As Image = pbOriginal.Image
 
        Using g As Graphics = Graphics.FromImage(b)
 
            Dim tbmp As New Bitmap(pbOriginal.Width, pbOriginal.Height) _
              'temporäres Bitmap erzeugen
 
            Dim r As New Rectangle
            r.Height = pbOriginal.Height
            r.Width = pbOriginal.Width
 
            pbOriginal.DrawToBitmap(tbmp, r) 'Inhalt der Picturebox 
            ' Hineinzeichnen
            pbLupe.Image = tbmp
 
            g.DrawImage(tbmp, New Rectangle(0, 0, pbOriginal.Width, _
              pbOriginal.Height), _
                                                New Rectangle(e.X - 15, e.Y - _
                                                20, 30, 40), GraphicsUnit.Pixel)