Private Function BitmapDiff(ByVal b1 As Bitmap, ByVal b2 As Bitmap) As Bitmap
 
        ' Zulaessige Abweichung des Farbwertes
        Dim bm As New Bitmap(b1.Width, b1.Height)
        Dim A As Integer
        Dim B As Integer
        A = 0
        B = 0
        For y As Integer = 0 To b1.Height - 1
            f2.ProgressBar1.Value = y / 480 * 100
            For x As Integer = 0 To b1.Width - 1
                If b1.GetPixel(x, y) <> b2.GetPixel(x, y) Then
                    bm.SetPixel(x, y, Color.Black)
                    y = y + 1
                Else
                    bm.SetPixel(x, y, Color.White)
                    x = x + 1
                End If
            Next
        Next
        Pro1 = Math.Round(A / 307200 * 100.0, 2)
        Pro2 = Math.Round(B / 307200 * 100.0, 2)
 
        MessageBox.Show("Richtig :" & Pro1 & ", Falsch :" & Pro2)
        Return bm
    End Function

If b1.GetPixel(x, y) <> b2.GetPixel(x, y) Then