for (int i = 0; i < imm.Rows.Count; i++)
        {
            byte[] dati = new byte[0];
            dati = (byte[])imm.Rows[i]["FILE_FOTO_RIDOTTA_1"];
            FileStream fs = new FileStream("C:\\temp\\File_" + i.ToString()+".jpg", FileMode.Create, FileAccess.Write);
            fs.Write(dati, 0, dati.Length);
            fs.Close();
            imm.Rows[i]["INDIRIZZO"] = "file://C:\\temp\\File_" + i.ToString()+".jpg";
            
        }