How to display/show image in crystal report-13

Create a BLOB field in database with a column Name COLUMNNAME.
Use the following code for getting the reference of the image

Private Function authSign(ByVal doccode As String) As DataTable
       'here i have define a simple datatable inwhich image will recide
       Dim dt As New DataTable()
       'object of data row
       Dim drow As DataRow
       ' add the column in table to store the image of Byte array type
       dt.Columns.Add("COLUMNNAME", System.Type.GetType("System.Byte[]"))
       drow = dt.NewRow
       ' define the filestream object to read the image
       Dim fs As FileStream
       ' define te binary reader to read the bytes of image
       Dim br As BinaryReader
       ' check the existance of image
       If (File.Exists(AppDomain.CurrentDomain.BaseDirectory + "\Lab Reports\Signatures\" + doccode + ".JPG")) Then
           ' open image in file stream
           fs = New FileStream(AppDomain.CurrentDomain.BaseDirectory + "\Lab Reports\Signatures\" + doccode + ".JPG", FileMode.Open)
       Else
           ' if phot does not exist show the nophoto.jpg file
           fs = New FileStream(AppDomain.CurrentDomain.BaseDirectory + "\Lab Reports\Signatures\noSign.jpg", FileMode.Open)
       End If
       ' initialise the binary reader from file streamobject
       br = New BinaryReader(fs)
       ' define the byte array of filelength
       Dim imgbyte(fs.Length + 1) As Byte
       ' read the bytes from the binary reader
       imgbyte = br.ReadBytes(Convert.ToInt32((fs.Length)))
       drow("COLUMNNAME") = imgbyte
       ' add the image in bytearray
       dt.Rows.Add(drow)
       ' add row into the datatable
       br.Close()
       ' close the binary reader
       fs.Close()
       ' close the file stream
       Return dt
   End Function

Returned Datatable can be passed as a sourse to ur report or ur subreport.Here i used subreport
of report name AuthSignature.rpt in my main report

Dim report1 As New ReportDocument
       Dim auth As New DataTable
       auth.Columns.Add("COLUMNNAME", System.Type.GetType("System.Byte[]"))
       auth = authSign(OrderDtlType.t_ILS_ORDTAUTHDOCTORCODE)
       report1.Subreports("AuthSignature.rpt").SetDataSource(auth)
       CrystalReportViewer_rad.ReportSource = report1
       CrystalReportViewer_rad.DataBind()