Synchronization of multi-user event media (SEM) at MediaEval 2014: Task description, datasets, and evaluation

In this paper we provide an overview of the Synchroniza- tion of Multi-User Event Media (SEM) Task that is part of the 2014 MediaEval Benchmark for Multimedia Evaluation. The SEM task is presented this year for the rst time in MediaEval, and poses a new challenge, namely the temporal alignment of a series of photo galleries that relate to the same event but have been collected by di erent users. Besides aligning the pictures on a common timeline, participants are also required to detect the sub-events attended by the users and to group the pictures accordingly. The task is validated on two different datasets related to the 2010 and 2012 Winter / Summer Olympic games, each dataset comprising a variable number of pictures, galleries, and sub-events.