I solved the problem.. thanks
Class1 cl = new Class1();
string ID = Session["IDUSER"].ToString();
byte[] bytes = (byte[])cl._Get_PicInfoGV(" WHERE EmailID = '" + ID + "'").Rows[0]["PicData"];
string base64String = Convert.ToBase64String(bytes, 0, bytes.Length);
Image1.ImageUrl = "data:image/png;base64," + base64String;