Public Function ZoomBitmap(bmp As Bitmap, new_height As Integer) As Bitmap
 
     If bmp.Height = new_height Then Return DirectCast(bmp.Clone, Bitmap)
 
     Dim rect_source As New Rectangle(0, 0, bmp.Width, bmp.Height)
 
     Dim new_width As Integer = CInt(new_height / bmp.Height * bmp.Width)
     Dim rect_zoom As New Rectangle(0, 0, new_width, new_height)
 
     Dim bmp_zoom As New Bitmap(new_width, new_height)
     Using g As Graphics = Graphics.FromImage(bmp_zoom)
        g.DrawImage(bmp, rect_zoom, rect_source, Drawing.GraphicsUnit.Pixel)
     End Using
     Return bmp_zoom
 End Function
 
 
Public Function CombineBitmaps(bmp_left As Bitmap, _
      bmp_right As Bitmap) As Bitmap
 
     Dim new_height As Integer = Math.Max(bmp_left.Height, bmp_right.Height)
     Dim new_width As Integer = bmp_left.Width + bmp_right.Width
 
     Dim bmp_combine As New Bitmap(new_width, new_height)
 
     Using bmp_left_zoom As Bitmap = ZoomBitmap(bmp_left, new_height),
        bmp_right_zoom As Bitmap = ZoomBitmap(bmp_right, new_height), _
        g As Graphics = Graphics.FromImage(bmp_combine)
 
        g.DrawImage(bmp_left_zoom, 0, 0)
        g.DrawImage(bmp_right_zoom, bmp_left_zoom.Width, 0)
     End Using
     Return bmp_combine
 End Function

      pb.Image = _
      CombineBitmaps _
        (New Bitmap("C:\daten\ew.jpg"), New Bitmap("C:\daten\ks.jpg"))

Public Shared Function CombineBitmaps(bmp_left As Bitmap, _
   bmp_right As Bitmap) As Bitmap
 
   Dim new_height As Integer = Math.Max(bmp_left.Height, bmp_right.Height)
   Dim bmp_combine As Bitmap
 
   Using bmp_left_zoom As Bitmap = ZoomBitmap(bmp_left, new_height), _
      bmp_right_zoom As Bitmap = ZoomBitmap(bmp_right, new_height)
 
      bmp_combine = New Bitmap _
         (bmp_left_zoom.Width + bmp_right_zoom.Width, new_height)
 
      Using g As Graphics = Graphics.FromImage(bmp_combine)
 
          g.DrawImage(bmp_left_zoom, 0, 0)
          g.DrawImage(bmp_right_zoom, bmp_left_zoom.Width, 0)
      End Using
   End Using
   Return bmp_combine
End Function

 Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles _
      Button1.Click
        pb.Image = CombineBitmaps _
        (New Bitmap("C:\daten\ew.jpg"), New Bitmap("C:\daten\ks.jpg"))
        pb.Image.Save("C:\daten\new.jpg")
    End Sub
 
 
    Public Function CombineBitmaps(bmp_left As Bitmap,
      bmp_right As Bitmap) As Bitmap
 
        'Höhe der beiden Teilbiler ermitteln
        Dim new_height As Integer = bmp_left.Height + bmp_right.Height
 
        'Breite ermitteln (vom breitesten Teilbild)
        Dim new_width As Integer = Math.Max(bmp_left.Width, bmp_right.Width)
 
        'Neues Bildformat mit berechnete Höhe und Breite aus den beiden 
        ' Teilbilder
        Dim bmp_combine As New Bitmap(new_width, new_height)
        Dim g As Graphics = Graphics.FromImage(bmp_combine)
        g.DrawImage(bmp_left, 0, 0)
        g.DrawImage(bmp_right, 0, bmp_left.Height)
        Return bmp_combine
    End Function
 
End Class

   Public Function IsEqual(col1 As Color, _
                                  col2 As Color) As Boolean
        If col1.R <> col2.R Then Return False
        If col1.G <> col2.G Then Return False
        If col1.B <> col2.B Then Return False
        Return True
   End Function
 
 
   Public Function RemoveOutRegion(ByVal bmp As Bitmap, _
                          ByVal OutRegionColor As Color) As Bitmap
 
      Dim topleft As New Point(0, 0)
      Dim bottomright As New Point(bmp.Width - 1, bmp.Height - 1)
 
      Dim found As Boolean = False
      Dim i, k As Integer
      k = -1
      Do
         k += 1
         If k = bmp.Width Then
            k = 0 : i += 1
            If i = bmp.Height Then Return Nothing
         End If
 
         found = Not IsEqual(bmp.GetPixel(k, i), OutRegionColor)
     Loop Until found
     If Not found Then Return Nothing
     topleft = New Point(k, i)
 
     found = False
     k = bmp.Width : i = bmp.Height - 1
     Do
        k -= 1
        If k = -1 Then
           k = bmp.Width - 1 : i -= 1
           If i = -1 Then Return Nothing
        End If
        found = Not IsEqual(bmp.GetPixel(k, i), OutRegionColor)
     Loop Until found
 
     bottomright = New Point(k, i)
 
     Dim rect_source As New Rectangle _
        (topleft, New Size(bottomright.X - topleft.X, bottomright.Y - _
        topleft.Y))
 
     If rect_source.Width < 2 OrElse _        
        rect_source.Height < 2 Then Return Nothing
 
     Dim rect_dest As New Rectangle(New Point(0, 0), rect_source.Size)
     Dim bmp_center As New Bitmap(rect_source.Width, rect_source.Height)
 
     Using g As Graphics = Graphics.FromImage(bmp_center)
        g.DrawImage(bmp, rect_dest, rect_source, GraphicsUnit.Pixel)
     End Using
 
     Return bmp_center
 
  End Function