Dataset of the paper: "Chen, Zihong, Lingxiang Zheng, Yuqi Chen, and Yixiong Zhang. "2D hand tracking based on flocking with obstacle avoidance." Int J Adv Robot Syst 11 (2014): 22."  http://www.intechopen.com/journals/international_journal_of_advanced_robotic_systems/2d-hand-tracking-based-on-flocking-with-obstacle-avoidance