Why image cannot be saved in database - sql-server

Question

I'm using VB.NET and SQL Server for my system. I have a problem saving an image into the database. I need to save and retrieve image on the same page but I get an error:
unable to cast System.DBNull to system bytes.
I have tried several coding to fix my coding but it does not worked.
Code for retrieve image.
Dim id As String = txtImages.Text.Trim() 'txtImages is textbox name
Image1.Visible = id <> ""
If id <> "" Then
Dim dt As DataTable = GetData((Convert.ToString("SELECT ImagePic FROM masterlist WHERE id
='") & Request.QueryString("id")) + "'") 'image data will be select depend on what user search in the
serch textbox
If dt.Rows.Count > 0 Then
Dim bytes As Byte() = TryCast(dt.Rows(0)("ImagePic"), Byte())
Dim base64String As String = Convert.ToBase64String(bytes, 0, bytes.Length)
Image1.ImageUrl = Convert.ToString("data:images/png;base64,") & base64String
Else
Image1.ImageUrl = ""
Image1.AlternateText = "No image present in database with the name" 'if there is no image
in db the message will displayed
End If
End If
End Sub
Code for save image
Dim fileName As String = String.Empty
Dim filePath As String = String.Empty
Dim getPath As String = String.Empty
Dim pathToStore As String = String.Empty
Dim bytes As [Byte]()
Dim fs As FileStreamenter code here
Dim br As BinaryReader
Dim cmd As New SqlCommand("Updateonlyimage_Sp3", cs) ' SQL command for this page is inside SQL Server I declare it as Insertapprovalcustom_Sp2"
cmd.CommandType = CommandType.StoredProcedure
Try
If FileUpload1.HasFile Then
fileName = FileUpload1.FileName
filePath = Server.MapPath("HSCODE/" & Convert.ToString(System.Guid.NewGuid()) & fileName)
'path to doucument inside approval_pdf file
FileUpload1.SaveAs(filePath)
cmd.Parameters.AddWithValue("#id", Request.QueryString("id"))
cmd.Parameters.AddWithValue("#ImagePicName", fileName)
Dim getPos As Integer = filePath.LastIndexOf("\")
Dim len As Integer = filePath.Length()
getPath = filePath.Substring(getPos, len - getPos)
pathToStore = getPath.Remove(0, 1)
cmd.Parameters.AddWithValue("#ImagePicPath", pathToStore)
fs = New FileStream(filePath, FileMode.Open, FileAccess.Read)
br = New BinaryReader(fs)
bytes = br.ReadBytes(Convert.ToInt32(fs.Length))
br.Close()
fs.Close()
cmd.Parameters.AddWithValue("#ImagePic", bytes)
cmd.Parameters.AddWithValue("#ContentType", FileUpload1.PostedFile.ContentType)