# Extending Appearance Based Gait Recognition with Depth Data
## 5 Experimental Validation
### Results
\begin{table}
\begin{tabular}{l c c c c c c c c c} \hline \hline
**Population Size** & \multicolumn{2}{c}{**32**} & \multicolumn{2}{c}{**155**} & \multicolumn{2}{c}{**305**} \\ \hline
**Metric** & **Accuracy** & **F1** & **Kappa** & **Accuracy** & **F1** & **Kappa** & **Accuracy** & **F1** & **Kappa** \\ \hline \multicolumn{10}{l}{Normal (N) variation} \\ \hline Height & 0.43 & 0.4 & 0.41 & 0.13 & 0.11 & 0.13 & 0.08 & 0.07 & 0.08 \\ GEI & 0.97 & 0.96 & 0.97 & 0.99 & 0.99 & 0.99 & 0.97 & 0.96 & 0.97 \\ HGEI-i & 1 & 1 & 1 & 1 & 1 & 1 & 0.99 & 0.99 & 0.99 \\ HGEI-f & 0.97 & 0.97 & 0.97 & 0.89 & 0.88 & 0.89 & 0.77 & 0.74 & 0.77 \\ BGEI & 0.98 & 0.98 & 0.98 & 0.94 & 0.93 & 0.94 & 0.88 & 0.86 & 0.88 \\ HBGEI-i & 1 & 1 & 1 & 0.98 & 0.98 & 0.98 & 0.97 & 0.96 & 0.97 \\ HBGEI-f & 0.97 & 0.96 & 0.97 & 0.87 & 0.86 & 0.87 & 0.75 & 0.72 & 0.75 \\ \hline \multicolumn{10}{l}{Backpack (B) variation} \\ \hline Height & 0.43 & 0.4 & 0.42 & 0.13 & 0.12 & 0.13 & 0.08 & 0.07 & 0.08 \\ GEI & 0.97 & 0.97 & 0.97 & 0.89 & 0.86 & 0.89 & 0.8 & 0.78 & 0.8 \\ HGEI-i & 1 & 1 & 1 & 0.96 & 0.95 & 0.96 & 0.93 & 0.91 & 0.93 \\ HGEI-f & 0.96 & 0.95 & 0.96 & 0.83 & 0.81 & 0.83 & 0.67 & 0.63 & 0.67 \\ BGEI & 0.84 & 0.82 & 0.84 & 0.74 & 0.71 & 0.74 & 0.63 & 0.59 & 0.63 \\ HBGEI-i & 0.96 & 0.96 & 0.96 & 0.9 & 0.88 & 0.9 & 0.86 & 0.84 & 0.86 \\ HBGEI-f & 0.93 & 0.92 & 0.93 & 0.8 & 0.78 & 0.8 & 0.65 & 0.61 & 0.65 \\ \hline \multicolumn{10}{l}{Shoes (S) variation} \\ \hline Height & 0.42 & 0.39 & 0.4 & 0.13 & 0.12 & 0.13 & 0.08 & 0.07 & 0.08 \\ GEI & 0.95 & 0.94 & 0.95 & 0.89 & 0.88 & 0.89 & 0.83 & 0.81 & 0.83 \\ HGEI-i & 1 & 1 & 1 & 0.96 & 0.96 & 0.96 & 0.93 & 0.93 & 0.93 \\ HGEI-f & 0.96 & 0.95 & 0.96 & 0.84 & 0.82 & 0.84 & 0.69 & 0.65 & 0.69 \\ BGEI & 0.91 & 0.9 & 0.9 & 0.78 & 0.75 & 0.78 & 0.7 & 0.66 & 0.7 \\ HBGEI-i & 0.98 & 0.98 & 0.98 & 0.92 & 0.91 & 0.92 & 0.87 & 0.85 & 0.87 \\ HBGEI-f & 0.94 & 0.93 & 0.94 & 0.81 & 0.79 & 0.81 & 0.66 & 0.62 & 0.66 \\ \hline \multicolumn{10}{l}{Time normal (TN) variation} \\ \hline Height & 0.43 & 0.42 & 0.42 & 0.13 & 0.06 & 0.12 & 0.07 & 0.02 & 0.06 \\ GEI & 0.44 & 0.38 & 0.42 & 0.27 & 0.16 & 0.26 & 0.21 & 0.09 & 0.2 \\ HGEI-i & 0.64 & 0.58 & 0.62 & 0.42 & 0.26 & 0.41 & 0.35 & 0.17 & 0.34 \\ HGEI-f & 0.68 & 0.65 & 0.67 & 0.4 & 0.24 & 0.39 & 0.25 & 0.1 & 0.24 \\ BGEI & 0.35 & 0.3 & 0.33 & 0.23 & 0.1 & 0.22 & 0.2 & 0.07 & 0.19 \\ HBGEI-i & 0.67 & 0.61 & 0.66 & 0.42 & 0.24 & 0.41 & 0.33 & 0.15 & 0.32 \\ HBGEI-f & 0.65 & 0.61 & 0.64 & 0.41 & 0.23 & 0.4 & 0.3 & 0.13 & 0.29 \\ \hline \multicolumn{10}{l}{Time backpack (TB) variation} \\ \hline Height & 0.43 & 0.4 & 0.41 & 0.14 & 0.08 & 0.13 & 0.07 & 0.04 & 0.06 \\ GEI & 0.34 & 0.27 & 0.32 & 0.17 & 0.09 & 0.16 & 0.11 & 0.05 & 0.1 \\ HGEI-i & 0.65 & 0.58 & 0.63 & 0.45 & 0.32 & 0.44 & 0.33 & 0.2 & 0.32 \\ HGEI-f & 0.65 & 0.59 & 0.64 & 0.43 & 0.29 & 0.42 & 0.24 & 0.13 & 0.23 \\ BGEI & 0.22 & 0.17 & 0.19 & 0.12 & 0.06 & 0.12 & 0.09 & 0.04 & 0.09 \\ HBGEI-i & 0.62 & 0.57 & 0.61 & 0.43 & 0.27 & 0.42 & 0.3 & 0.15 & 0.29 \\ HBGEI-f & 0.41 & 0.36 & 0.39 & 0.17 & 0.1 & 0.16 & 0.1 & 0.05 & 0.1 \\ \hline \multicolumn{10}{l}{Time shoes (TS) variation} \\ \hline Height & 0.44 & 0.41 & 0.42 & 0.13 & 0.07 & 0.12 & 0.07 & 0.04 & 0.07 \\ GEI & 0.33 & 0.26 & 0.31 & 0.19 & 0.11 & 0.18 & 0.17 & 0.08 & 0.16 \\ HGEI-i & 0.63 & 0.57 & 0.62 & 0.32 & 0.2 & 0.31 & 0.24 & 0.13 & 0.23 \\ HGEI-f & 0.7 & 0.69 & 0.69 & 0.38 & 0.25 & 0 The decrease in performance for _time normal_, _time backpack_, and _time shoes_ variations is not so marked for the Height method, which is less susceptible to changes in appearance. The methods that combine appearance based gait features and the height feature performed best in all cases. HGEI-i shows the best overall accuracy across different populations and different variants