Dim PrintWidth, PrintHeight As Integer                 'Größe Druckfläche
  Dim outWidth, outHeight, outLeft, outTop As Integer    'Druckgröße Bild 
  PrintWidth = 1024 : PrintHeight = 756                  'Anpassen für DIN A4 
 
  Dim bmp_in As New Drawing.Bitmap("Bilddatei original Screenshot")
  Dim bmp_out As New Drawing.Bitmap(PrintWidth, PrintHeight)
  Dim g As Drawing.Graphics = Drawing.Graphics.FromImage(bmp_out)
  g.Clear(Drawing.Color.White)
  'Positionieren und Zoomen
  outWidth = CInt(bmp_in.Width / bmp_in.Height * PrintHeight)
  outHeight = PrintHeight
  outLeft = CInt((PrintWidth - outWidth) / 2) : outTop = 0
  If outWidth > PrintWidth Then
     outHeight = CInt(bmp_in.Height / bmp_in.Width * PrintWidth)
     outWidth = PrintWidth
     outTop = CInt((PrintHeight - outHeight) / 2) : outLeft = 0
  End If
 
  'Bild in Fläche eintragen 
  g.DrawImage(bmp_in, outLeft, outTop, outWidth, outHeight)
  'Bild speichern
  bmp_out.Save("Ausgabebild", Drawing.Imaging.ImageFormat.Jpeg)