Fail to hide empty cells in UITableView Swift

I'm using UITableView in a swift application, and using my own custom UITableViewCell.

When trying to hide the empty cells in the UITableView, its still have the white background.

Under the UITableView I have a background image (UImageView).

I'v already try to hide those cells, and actually they are hidden, but I still have a white background, using this code:

override func viewDidLoad() {
    super.viewDidLoad()
    var tblView =  UIView(frame: CGRect(x: 0,y: 0,width: 0,height: 0))
    tblView.backgroundColor = UIColor.clearColor()
    tableView.tableFooterView = tblView

    var nipName=UINib(nibName: "CustomCell", bundle:nil)
    self.tableView.registerNib(nipName, forCellReuseIdentifier: "CustomCell")
}