Rate efficient remote video file synchronization

Video file synchronization between remote users is an important task in many applications. Re-transmission of a video that has been only slightly modified is expensive, wasteful and avoidable. We propose a scheme that automatically detects and sends only modified content according to some user defined distortion constraint to enable rate savings under a wide range of video edits. Through the use of a low-rate hierarchical hashing scheme, we can detect modifications with some spatial granularity. We also apply distributed source coding techniques to exploit correlation between remote copies for a further rate rebate. Experimental results show that the proposed approach achieves up to 7times rate reduction when compared to re-transmitting.