“…They can be classified in two groups: event clustering approaches [5][6][7][8][9][10][11] and event hybrid approaches [12,14,17,21,27,28]. Extracting events from multimedia in terms of photographs or images is much more difficult when compared to text for essentially two reasons: i) Event detection from images requires aggregation of heterogeneous metadata [29]; ii) Linking multimedia data to event model aspects is far more challenging then textual data [30]. In fact, many aspects of an event should be taken into consideration, as described in the multimedia event model presented in [13], such as time, space, actors, granularities, sub-events, etc.…”