UIImagePickerControllerカメラのライブラリボタンを表示する簡単な方法

カメラビュー（UIImagePickerController）にライブラリボタンを表示しようとしています。ここに私のコードです：UIImagePickerControllerカメラのライブラリボタンを表示する簡単な方法

- (void)takePhoto{ 
    _imagePicker = [[UIImagePickerController alloc] init]; 
    [_imagePicker setSourceType:UIImagePickerControllerSourceTypeCamera]; 
    [_imagePicker setDelegate:self]; 
    _imagePicker.allowsEditing = YES; 
    CGRect frame = self.view.frame; 
    int y = frame.size.height; 
    int x = frame.size.width; 

    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(x-100, y-50-1, 100, 30)]; 
    [button setTitle:@"Library" forState:UIControlStateNormal]; 
    [button setBackgroundColor:[UIColor clearColor]]; 
    [button addTarget:self action:@selector(gotoLibrary:) forControlEvents:UIControlEventTouchUpInside]; 

    [_imagePicker.view addSubview:button]; 

    [self presentViewController:_imagePicker animated:NO completion:nil]; 


} 
-(IBAction)gotoLibrary:(id)sender 
{ 
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init]; 
    [imagePicker.view setFrame:CGRectMake(0, 80, 450, 350)]; 
    [imagePicker setSourceType:UIImagePickerControllerSourceTypeSavedPhotosAlbum]; 
    imagePicker.allowsEditing = YES; 
    [imagePicker setDelegate:self]; 

    [_imagePicker presentViewController:imagePicker animated:YES completion:nil]; 
}

私は写真を撮ろうとすると画像に問題があります。写真を撮るときにライブラリボタンを隠すにはどうすればいいですか？ How it looks like