convert VB to C#

Pilz.Drawing/BitmapExtensions.vb

@@ -1,20 +0,0 @@
-Imports System.Drawing
-Imports System.Runtime.CompilerServices
-
-Public Module BitmapExtensions
-
-    <Extension>
-    Public Sub InvertColors(bmp As Bitmap)
-        For y As Integer = 0 To bmp.Height - 1
-            For x As Integer = 0 To bmp.Width - 1
-                Dim inv As Color = bmp.GetPixel(x, y)
-                inv = Color.FromArgb(inv.A,
-                                     Byte.MaxValue - inv.R,
-                                     Byte.MaxValue - inv.G,
-                                     Byte.MaxValue - inv.B)
-                bmp.SetPixel(x, y, inv)
-            Next
-        Next
-    End Sub
-
-End Module