自定义标签栏项目swift 3

Question

我有一个自定义标签栏项目图片，也是用户的个人资料图片。图像模糊不清，我知道这是因为我使用的设备。我不确定如何设置用户上传到2x和3x的图像，因为图像不在assets文件夹中。以下是我设置自定义标签栏项目的方法：

    override func awakeFromNib() {
        super.awakeFromNib()

        self.tabBarItem.title = "MY ACCOUNT"
        self.tabBarItem.image = UIImage(named: "MySpace Filled-50")

        if self.loggedInUserUid != nil {

            let imageRef = FIRStorage.storage().reference().child((loggedInUserUid)!+"/profile_pic.jpg")

            imageRef.data(withMaxSize: 1 * 1024 * 1024, completion: { (data, error) -> Void in
                if error != nil {
                    print(error!)
                    return
                }

                DispatchQueue.main.async(execute: {
                    let image = UIImage(data: data!)
                    let imaged = self.resizeImage(image: (image?.withRenderingMode(.alwaysOriginal))!, newWidth: 30)
                    let imaggged = self.maskRoundedImage(image: imaged!, radius: 15)

                    self.tabBarItem.image = imaggged.withRenderingMode(.alwaysOriginal)
                    self.tabBarItem.selectedImage = imaggged.withRenderingMode(.alwaysOriginal)

                })

            }).resume()
} }