我可以使用jpeg图片启动屏幕吗
我目前正在开发应用程序，并且我添加了JPEG格式的启动器屏幕，该屏幕同时在模拟器和设备中显示..但这是否对苹果批准准则造成任何问题?
i was currently in to an app development and i have added a launcher screen in JPEG format which is displayed both in simulator and device .. but does it create any problem with apple approval guidelines ?
Update for iOS 8+: you can now use XIB-based launch assets, which is by far the best approach to reduce file size and re-use the same assets for multiple screens sizes. Also, since XIBs support JPG assets, you can always embed JPGs onto XIB files now too!
iOS 8之前的Apple文档(现已删除)明确声明，启动映像仅允许使用PNG:
The Apple documentation pre iOS 8 (now removed), explicitly stated that only PNG is allowed for the launch image:
应用启动(默认)图像
每个应用程序都必须提供至少一个启动映像.该图像是通常在一个名为Default.png的文件中，该文件会显示您应用的首字母屏幕以纵向显示.但是，您也可以提供其他在不同的启动条件下使用的启动图像.全部启动图片必须是PNG 文件，并且必须位于您的顶层应用程序的捆绑目录.(避免使用隔行扫描的PNG.)
Every app must provide at least one launch image. This image is typically in a file named Default.png that displays your app’s initial screen in a portrait orientation. However, you can also provide other launch images to be used under different launch conditions. All launch images must be PNG files and must reside in the top level of your app’s bundle directory. (Avoid using interlaced PNGs.)
我无法说出这份文件的准确性，但是看来他们在这方面很具体.
I can't speak to how accurate this document is, but it seems they are pretty specific on this point.
我的建议:使用8位PNG，如果您的文件越来越大，请不要在视网膜iPad上使用@ 2x版本.1x版本可以在视网膜iPad上很好地进行升级，比将您的应用程序膨胀5MB +更好
My advice: use 8-bit PNG's, and if your files are getting to big, simply don't include the @2x versions for the retina iPad. The 1x version upscales reasonably well on the retina iPad, and better than bloating your app by 5MB+