Human Skeleton Model Based Dynamic Features for Walking Speed Invariant Gait Recognition

Figure 6

Feature space transformation: (a) single subject’s features for fast walk (red) and slow walk (blue). (b) Slow and fast walk group mean and st. dev. (c) Slow walk features transformed to fast walk space. (d) Remaining differences after transformation. Note that 𝑦 axis in rows (a), (b), and (c) shows absolute (measured) values, while row (d) shows differences after normalization, which therefore appear relatively small compared to measured values. 𝑥 axis denotes the percent of gait cycle.