after updating image from data grid view getting black color instead of images

[jaseem0712]

I have a data grid view like this:



i am loading data grid view like this:

Dim cd As SqlCommandBuilder = New SqlCommandBuilder(adapter)
        adapter = New SqlDataAdapter("select c.cid,c.CompanyName,d.dtId,d.dtName as Department,d.dtPhone as Phone,d.dtEmail as Email,d.empimage from CompanyMaster_tbl c join  DepartmentMaster_tbl d on c.Cid=d.cId order by cid", con.connect)

        dt1 = New DataTable
        bSource = New BindingSource
        adapter.Fill(dt1) 'Filling dt with the information from the DB
        bSource.DataSource = dt1
        gv.DataSource = bSource
        gv.Columns("cid").Visible = False
        gv.Columns("dtId").Visible = False

in update button i wrote code like this:

adapter = New SqlDataAdapter()
      Dim cid As Integer
        Dim dtid As Integer
        Dim cmpname As String
        Dim dtname As String
        Dim dtPhone As String
        Dim dtEmail As String
        Dim dtimage As Image


        For i As Integer = 0 To gv.RowCount - 2
           Dim rv = DirectCast(gv.Rows(i).DataBoundItem, DataRowView)
            cid = rv.Row.Field(Of Integer)("Cid")

            dtid = rv.Row.Field(Of Integer)("dtId")
            cmpname = rv.Row.Field(Of String)("CompanyName")
            dtname = rv.Row.Field(Of String)("Department")
            dtPhone = rv.Row.Field(Of String)("Phone")
            dtEmail = rv.Row.Field(Of String)("Email")

            Using ms As New MemoryStream(rv.Row.Field(Of Byte())("empimage"))
                dtimage = New Bitmap(ms)
            End Using

            adapter.UpdateCommand = New SqlCommand("UPDATE CompanyMaster_tbl SET CompanyName = @CompanyName", con.connect)
            'this code for updating image also..
            adapter.UpdateCommand = New SqlCommand("update DepartmentMaster_tbl set dtName = @dtName,dtPhone = @dtPhone,dtEmail = @dtEmail,empimage=@dtimage  where dtId=@dtid", con.connect)
            adapter.UpdateCommand.Parameters.AddWithValue("@Cid", cid)
            adapter.UpdateCommand.Parameters.AddWithValue("@CompanyName", cmpname)
            adapter.UpdateCommand.Parameters.AddWithValue("@dtId", dtid)
            adapter.UpdateCommand.Parameters.AddWithValue("@dtName", dtname)
            adapter.UpdateCommand.Parameters.AddWithValue("@dtPhone", dtPhone)
            adapter.UpdateCommand.Parameters.AddWithValue("@dtEmail", dtEmail)

            Dim md As New MemoryStream()
            dtimage.Save(md, System.Drawing.Imaging.ImageFormat.Gif)
         ' read to end
            Dim bmpBytes As Byte() = md.GetBuffer()

            ' Dim image As Byte() = System.IO.File.ReadAllBytes()
            adapter.UpdateCommand.Parameters.AddWithValue("@dtimage", bmpBytes)
            'adapter.UpdateCommand.Parameters.AddWithValue("@dtimage", dtimage)
            adapter.UpdateCommand.ExecuteNonQuery()

after updating my first 4 column of data grid view coming proper,,but image coming something like back color,,like this:


what is wrong with my code?? any help is very appreciable?