A recent patent application reveals that Apple is working on a multi-point touch focus method for the iPhone. (Perhaps the upcoming iPhone 5?)
Essentially, you will be able to select two regions of interest in a give scene and the iPhone will optimize aperture and exposure settings for these two regions when capturing the image. In the event that the distance between the two regions of interest is substantial, the camera function may select a compromise point of focus between the two points to make both areas as sharps as possible.
The patent application further demonstrates that the iPhone may apply sharpening in processing of the image in order to further optimize the multiple points of interest. Motion tracking is also mentioned so that identifiable objects may be tracked for focus.
The “region of interest” can be selected with a simple tap, or a larger/smaller region can be adjusted with a pinch on the focus box. Additionally, the focus and exposure evaluation of multiple areas is mentioned for both photo and video capture.
This patent application also references the potential use of a dedicated image processor that will work apart from the iPhone’s main processor. I don’t think the current iPhone 4S features a dedicated image processor (please correct me if I’m wrong), but that sounds like Apple is really taking the iPhone camera to the next level, along with some of the above features.
Those of you wanting to take a closer look at the full patent application can download it here: Apple Multi-Point Touch Focus Patent Application