Is there a way to capture images at a faster rate than using UIGetScreenImage (I can only get 3-6 images per second)? We've noticed some apps that appear not to use UIGetScreenImage (i know this because they're overlaying controls in the preview that isn't captured on the image) and they're able to capture up to 15 images per second and save to disk. Is there another way to capture and save images at a faster rate than UIGetScreenImage?