OpenCV for Android: Autofocus native camera

Question

Is it possible to control autofocus feature of Android camera, using OpenCV's libnative_camera*.so ?

Or maybe it's possible to manually set focus distance?

Is there alternative approach (May be, it's better to use Android API to control camera and then grab frame in onPreview events and pass it to native code)?

Answer 1

If your intention is to control the camera on your own, then Android Camera APIs suck. As such Android APIs suck when it comes to offering your hardware camera device number to JavaCV native camera library. Without a native device number, JavaCV would be clueless to connect to the appropriate camera (Front or Back).

If your intention is only to perform object detection and stuff, well Android Camera APIs coupled with JavaCV should work. Setup a callbackBuffer of sufficient size, setPreviewCallbackWithBuffer, setup sufficient preview frame-rate, and once you start getting preview-frames in ImageFormat.NV21 format (mind you!!, this is the only format supported for preview-frames even in ICS), pass them off to JavaCV for performing object detection.

AutoFocus on Android Camera APIs suck big time. I have been researching for over a month for feasible solutions.