问从Firebase下载的图像在只有200-400 in大小时，以某种方式占用了28 in的内存。

EN

@IBOutlet weak var imageView: UIImageView!

func updateUI(photo:Photo, image:UIImage? = nil) {
    //Call when preparing to show image
    if image != nil {
        print("Loaded from cache")
        imageView.image = image
        photo.assignImage(image: image!)
    } else {
        let url = photo.imageUrl
        let ref = FIRStorage.storage().reference(forURL: url)
        ref.data(withMaxSize: 5*1024*1024, completion: { [weak self] (data, error) in
            if error != nil {
                print("Unable to download image")
            } else {
                print("Image downloaded")
                if let imageData = data {
                    if let image = UIImage(data: imageData) {
                        self?.imageView.image = image
                        photo.assignImage(image: image)
                        TripsVC.imageCache.setObject(image, forKey: photo.uid as NSString)
                    }
                }
            }
        })
    }
}
}