Ios 在解除UISplitViewController中的UIImagePickerController时接收内存警告

我正在使用一个简单的

UISplitViewController

。在我的主视图（master）中，我可以选择使用

UIImagePickerController

从相机拍照，当用户完成拍照或点击取消时，我从控制台收到内存警告。有人知道为什么会这样吗

以下是我介绍控制器的方式：

if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
{
   cameraService = [[UIImagePickerController alloc] init];     
   cameraService.delegate    = self;
   cameraService.sourceType  = UIImagePickerControllerSourceTypeCamera;

   [self presentViewController:cameraService animated:YES completion:NULL];
}

下面是我如何取消图像选取器视图：

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    UIImage * image
        = (UIImage *)[info valueForKeyPath:UIImagePickerControllerOriginalImage]];

    [picker dismissViewControllerAnimated:YES completion:nil];
}

谢谢