iPhone SDK - What is the fastest way to grap an image from the camera and resize it to screen size?

Since UIGetScreenImage() is banned again I'm looking for another开发者_如何学C fast way to get a 320x480 image representation of the current camera picture.

What would be the fastest way to downsize the image from didFinishPickingMediaWithInfo and save it as an jpg?

---

You can access camera using AVFoundation tools as shown here