Pieter,

You have your answer, however here it is more complete so that you can do
all actions with it when it is your next question about a database. I have
eliminiated the to much writing using a memorystream what is mostly showed
in samples, although in your question that is needed and used as last part
in the sample.

Maybe you can use it.

Cor

\\\it needs a picturebox and four buttons on a page.
Private abyt() As Byte
Private fo As New OpenFileDialog
Private sf As New SaveFileDialog
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click
       'Reading a picture and put it in a bytearray
       If fo.ShowDialog = DialogResult.OK Then
           Dim fs As New IO.FileStream(fo.FileName, _
          IO.FileMode.Open)
           Dim br As New IO.BinaryReader(fs)
           abyt = br.ReadBytes(CInt(fs.Length))
           br.Close()
           'just to show the sample without a fileread error
           Dim ms As New IO.MemoryStream(abyt)
           Me.PictureBox1.Image = Image.FromStream(ms)
       End If
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal _
   e As System.EventArgs) Handles Button2.Click
       'writing a picture from a bytearray
       If sf.ShowDialog = DialogResult.OK Then
           Dim fs As New IO.FileStream(sf.FileName, _
               IO.FileMode.CreateNew)
           Dim bw As New IO.BinaryWriter(fs)
           bw.Write(abyt)
           bw.Close()
       End If
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal _
   e As System.EventArgs) Handles Button3.Click
       'writing a bytearray to a dataset
       Dim ds As New DataSet
       ds.Tables.Add(New DataTable("Photo"))
       ds.Tables(0).Columns.Add(New DataColumn("Sample"))
       ds.Tables(0).Columns(0).DataType =
System.Type.GetType("System.Byte[]")
       ds.Tables(0).Rows.Add(ds.Tables(0).NewRow)
       ds.Tables(0).Rows(0)(0) = abyt
       Dim sf As New SaveFileDialog
       If sf.ShowDialog = DialogResult.OK Then
           ds.WriteXml(sf.FileName, XmlWriteMode.WriteSchema)
       End If
End Sub
Private Sub Button4_Click(ByVal sender As System.Object, _
   ByVal e As System.EventArgs) Handles Button4.Click
       'reading a picture from a dataset
       Dim ds As New DataSet
       If fo.ShowDialog = DialogResult.OK Then
           ds.ReadXml(fo.FileName)
       End If
       abyt = CType(ds.Tables(0).Rows(0)(0), Byte())
       Dim ms As New IO.MemoryStream(abyt)
       Me.PictureBox1.Image = Image.FromStream(ms)
End Sub
///

Cor