Electronic Image Stabilization (EIS) is a highly effective method of compensating for hand jitter that manifests itself in distracting video shake during playback. EIS relies on an accurate motion sensor for tracking the source of jitter,which may be hand shake or vehicle motion for example. The motion information is then integrated during the current video frame and used to compensate for it by cropping the viewable image from a stream of video frames thru the imaging pipeline.
A key factor to successful compensation in an open OS system such as Android is consistent alignment of motion information to its corresponding video frame, as the motion pipeline and imaging pipeline are independent subsystems within the OS. InvenSense’s high performance motion sensors have a unique frame sync input that allows very accurate alignment with video frames, essentially synchronizing the two pipelines in the system. InvenSenes’s EIS Software IP takes advantage of this accurate synchronization to provide OEMs with a world-class EIS solution with repeatable and consistent performance regardless of image sensors used, reducing time to market.
Since EIS does not rely on nor is limited by mechanical compensation of optical methods, it can track and compensate for large input motion in sports-oriented applications for phones or action cameras. The large degree of compensation can even be used in drones to replace an expensive gimbals normally used to keep the camera steady during flight. The lack of mechanical complexity not only reduces the cost of the system; it also significantly improves reliability of the end devices in all applications.
A large degree of jitter compensation provided by InvenSense’s EIS Software compared to the native video stream. The resulting video is not only steady, it also reduces the artifacts of rolling shutter, a jello-like effect on video that happens as exposure time is increased in lower light and jitter causes gradual shift of the image capture from upper to lower end of the frame.