“…Each technique summarizes the video using a specific feature, such as trajectories, moving objects, abnormal detection, and many others. These categories of techniques can be classified into two general categories, scene-based (i.e., static [1-7, 9, 17, 21, 22], dynamic [8,12,13,16,[18][19][20] and content-based approaches, and the content-based approaches can be further decomposed into three types related to the content of the video including motion-based [10][11][12][13][14][15][16]20], action-based [21,22] and event-based [11,15,[17][18][19], as shown in Fig. 1.…”