基于骨骼轨迹聚合模型的课堂交互群体发现

Interactive Group Discovery Based on Skeleton Trajectory Aggregation Model in Class Environment

传统的课堂行为识别方法侧重于交互行为本身的辨识,而非群体发现。课堂环境下实现交互群体的准确定位与发现,是进行个体行为识别的基础,但存在由遮挡造成的行为数据缺失问题。使用骨骼数据表示人体行为及运动轨迹,具有不受光线和背景干扰、数据表达简单等优点。针对骨骼数据的多人交互群体发现进行研究,提出了一种基于骨骼轨迹聚合模型的交互群体发现算法(Interactive Group Discovery Algorithm Based on Skeleton Trajectory Aggregation,IGSTA)。首先,将骨骼数据标准化到以人为中心的坐标系,减小尺寸变化和初始位置不同对识别精度的影响;其次,提出了一种多核表示的骨骼轨迹聚合模型,准确描述了学生交互行为群体的变化;最后,对聚合后的骨骼轨迹进行聚类,实现交互群体发现。采用Kinect获取模拟的课堂学生交互行为视频,通过实验验证了该方法的有效性,即在骨骼节点缺失的情况下,仍可准确发现课堂环境下的学生交互群体。

Traditional class action recognition methods focus on the recognition of interactive behavior itself,not the group discovery.Accurate positioning and discovery of interactive groups in class environment is the basis for further individual behavior recognition,but there is a problem of missing behavior data caused by occlusion.Skeletal data represent human behavior and motion trajectory,and have the advantages of not being disturbed by light and background,and simple data expression.Aiming at multi-person interactive group discovery of skeleton data,an interactive group discovery algorithm based on skeleton trajectory aggregation(IGSTA)is proposed.Firstly,this paper standardizes the skeleton data into the human-centered coordinate system to reduce the impact on recognition accuracy of different body size and initial position of person.Secondly,a skeleton trajectory aggregation model based on multi-core representation is proposed to accurately describe the changes of students’interactive beha-vior groups.Finally,the aggregated skeleton trajectories are clustered to realize the discovery of interactive group.Kinect is used to obtain the simulated video of classroom student interaction behavior.Experiments proves the validity of the method,that is,in the case of missing skeleton nodes,the interaction group of students can be accurately found in class environment.