Efficient video sequences alignment using unbiased bidirectional dynamic time warping

In this paper, we propose an efficient technique to synchronize video sequences of events that are acquired via uncalibrated cameras at unknown and dynamically varying temporal offsets. Unlike other existing techniques that just take unidirectional alignment into consideration, the proposed technique considers symmetric alignments and compute the optimal alignment. We also establish sub-frame accuracy video alignment. The advantages of our approach are validated by tests conducted on several pairs of real and synthetic sequences. We present qualitative and quantitative comparisons with other existing techniques. A unique application of this work in generating high-resolution 4D MRI data from multiple low-resolution MRI scans is described.

► An efficient technique that can synchronize video sequences of similar events acquired using uncalibrated cameras.
► The proposed technique can handle scenes from different views, and the videos having dynamic time shift.
► The proposed technique considers symmetric alignments of videos and computes the optimal alignment.
► The technique obtains sub-frame accuracy video alignment and has been used in high-resolution 4D MRI data generation.
► The proposed technique achieves superior performance for both synthetic and real test sequences over existing techniques.