synchronization of multiple video recordings based on still camera flashes
Combining audiovisual sequences from different cameras requires precise alignment in time. Current synchronization techniques involve using geometrical properties such as camera positions and object features. In this paper, we present a synchronization method based on detecting flashes present in the video content. Such flashes, generated by still cameras, cause a sharp bright frame in the videos. They are detected using an adaptive threshold on luminance variation across the frames. The resulting flash sequences are searched for matches. The matching flashes indicate overlapping content, and allow determining the offset time between cameras. The experimental results from flash detection and flash sequence matching show perfect synchronization in all examined cases.
synchronization flash detection inexact string-matching