关键词: 轨迹模式, 序列模式挖掘, PrefixSpan算法

Abstract: A modified PrefixSpan algorithm is put forward to analyze the video target’s movement through their trajectories in this paper.In the algorithm，the trajectories are recoded through vector quantization.The modified PrefixSpan algorithm is utilized to mine the frequent and continuous patterns from them.An approximate string matching method is given to detect whether the video target’s movement is abnormal or not.Since this method needn’t to measure similarity among the trajectories，it can be well used in occasion where the trajectory set scale is very large or the num of trajectory distribution pattern is difficult to determine.The experiments on the trajectories of different scenes show that the method is effective.

Key words: trajectory pattern, sequential pattern mining, PrefixSpan algorithm