Hierarchical Spatio-Temporal Context Modeling for Action Recognition

The problem of recognizing actions in realistic videos is challenging yet absorbing owing to its great potentials in many practical applications. Most previous research is limited due to the use of simplified action databases under controlled environments or focus on excessively localized features without sufficiently encapsulating the spatiotemporal context. In this paper, we propose to model the spatio-temporal context information in a hierarchical way, where three levels of context are exploited in ascending order of abstraction: 1) point-level context (SIFT average descriptor), 2) intra-trajectory context (trajectory transition descriptor), and 3) inter-trajectory context (trajectory proximity descriptor). To obtain efficient and compact representations for the latter two levels, we encode the spatiotemporal context information into the transition matrix of a Markov process, and then extract its stationary distribution as the final context descriptor. Building on th...

• Type: Conference
• Year: 2009
• Where: CVPR
• Authors: Jintao Li, Ju Sun, Loong Fah Cheong, Shuicheng Yan, Tat-Seng Chua, Xiao Wu
• Keywords: Action Recognition, Computer Vision, CVPR 2009