Dim vorschau As Bitmap
vorschau = CType(Bitmap.FromFile("abc.jpg"), Bitmap)
 
Dim output As New Bitmap(vorschau.Width, vorschau.Height, vorschau.PixelFormat)
 
output.SetResolution(300, 300)
 
Using g As Graphics = Graphics.FromImage(output)
      g.DrawImage(vorschau, 0, 0)
End Using
output.Save("abcde.jpg", Imaging.ImageFormat.Jpeg)
vorschau.Dispose()
output.Dispose()