let trackbar = new TrackBar()
trackbar.Dock <- DockStyle.Fill
trackbar.Minimum <- 0
trackbar.Maximum <- 100
trackbar.Value <- 0
trackbar.TickFrequency <- 1
trackbar.MouseUp.Add(fun _ ->
    label.Text <- trackbar.Value.ToString()
    label.Invalidate()
    setQuality (int64(trackbar.Value))
    //setQuality 100L
    use stream = new FileStream(memory, FileMode.OpenOrCreate)
    image.Save(stream, codecInfo, myEncoderParameters)
    picture.Image <- Image.FromStream(stream)
    stream.Close()
    picture.Invalidate()
)
trackbar.Size <- new Size(100,20)