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"))