Module modBitmapFunctions
 
    <System.Runtime.CompilerServices.Extension()> _
    Public Function Zoom(ByVal bmp As Bitmap, _
        zoomfactor As Double) As Bitmap
 
        If bmp Is Nothing Then Return Nothing
 
        Dim newwidth As Integer = CInt(bmp.Width * zoomfactor)
        Dim newheight As Integer = CInt(bmp.Height * zoomfactor)
        If newwidth < 2 Or newheight < 2 Then Return Nothing
 
        Dim newrect As New Rectangle(0, 0, newwidth, newheight)
        Dim newbmp As New Bitmap(newwidth, newheight)
 
        Using g As Graphics = Graphics.FromImage(newbmp)
            g.DrawImage(bmp, newrect)
        End Using
        Return newbmp
    End Function
End Module