''' <summary>
    ''' Bild Beschneiden entfernt den unnötigen Rand eines Bildes
    ''' </summary>
    ''' <param name="bmp">Das zu beschneidene Bild</param>
    ''' <returns>Neues beschnittenes Bild</returns>
    Public Function Beschneiden(ByVal Bmp As Bitmap) As Bitmap
 
        Dim CropRight As Integer, CropLeft As Integer, CropTop As Integer, _
          CropBottom As Integer
 
        'von Links
        For CropLeft = 0 To Bmp.Width - 1
            If beschneiden_check_row(Bmp, CropLeft) = False Then CropLeft -= 1 _
              : Exit For
        Next
        If CropLeft = -1 Then CropLeft = 0
        'von Rechts
        For CropRight = Bmp.Width - 1 To 0 Step -1
            If beschneiden_check_row(Bmp, CropRight) = False Then CropRight += _
              1 : Exit For
        Next
        'von Oben
        For CropTop = 0 To Bmp.Height - 1
            If beschneiden_check_col(Bmp, CropTop) = False Then CropTop -= 1 : _
              Exit For
        Next
        If CropTop = -1 Then CropTop = 0
        'von Unten
        For CropBottom = Bmp.Height - 1 To 1 Step -1
            If beschneiden_check_col(Bmp, CropBottom) = False Then CropBottom _
              += 1 : Exit For
        Next
 
        If CropBottom = Bmp.Height And CropTop = 0 And CropLeft = 0 And _
          CropRight = Bmp.Width Then Return Bmp
 
        Dim NewWidth As Integer = CropRight - CropLeft
        Dim NewHeight As Integer = CropBottom - CropTop
 
        Dim fixBmp As Bitmap = New Bitmap(NewWidth, NewHeight, _
          PixelFormat.Format32bppArgb)
 
        Dim g As Drawing.Graphics = Graphics.FromImage(fixBmp)
        g.Clear(Color.White)
        g.SmoothingMode = SmoothingMode.HighQuality
        g.CompositingQuality = CompositingQuality.HighQuality
        g.InterpolationMode = InterpolationMode.High
 
        g.DrawImage(Bmp, New RectangleF(0, 0, NewWidth, NewHeight), New _
          RectangleF(CropLeft, CropTop, NewWidth, NewHeight), _
          GraphicsUnit.Pixel)
 
        Return (fixBmp)
        g.Dispose()
        fixBmp.Dispose()
 
    End Function
 
    Function beschneiden_check_row(ByVal bmp As Bitmap, ByVal Row As Integer) _
      As Boolean
        Dim FirstColor As Integer = bmp.GetPixel(Row, 0).R
        For Col As Integer = 0 To bmp.Height - 1
            If bmp.GetPixel(Row, Col).R <> FirstColor Then Return False
        Next
        Return True
    End Function
 
    Function beschneiden_check_col(ByVal bmp As Bitmap, ByVal Col As Integer) _
      As Boolean
        Dim FirstColor As Integer = bmp.GetPixel(0, Col).R
        For Row As Integer = 0 To bmp.Width - 1
            If bmp.GetPixel(Row, Col).R <> FirstColor Then Return False
        Next
        Return True
    End Function

Joachim