Any assets under public will be served as static files by the
application or web server. You should use app/assets for files that
must undergo some pre-processing before they are served.

http://guides.rubyonrails.org/asset_pipeline.html

对我来说,这表示图像应该保留在公共目录中,因为我们的网络服务器可以静态地提供图像,并且不需要预处理.

将图像投入资产有什么优势吗？