# Personal Identification Using Embedded Raspberry Pi-Based Face Recognition Systems
## 3 Verification System
### Effectiveness of Recognition Depending on Facial Expressions  
With a fixed similarity threshold of 85% and consistent conditions for capturing reference images (frontal face samples relative to the camera, taken under identical artificial lighting in the same room with the same background), tests were conducted to evaluate the application's effectiveness using test images with varying facial expressions (Figure 13). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Conditions** & \begin{tabular}{c} **User No. 1** \\ **([PERSON])** \\ \end{tabular} & \begin{tabular}{c} **User No. 2** \\ **([PERSON])** \\ \end{tabular} & \begin{tabular}{c} **User No. 3** \\ **([PERSON])** \\ \end{tabular} & \begin{tabular}{c} **User No. 4** \\ **([PERSON])** \\ \end{tabular} & \
\begin{tabular}{c} **User No. 5** \\ **([PERSON])** \\ \end{tabular} &
\begin{tabular}{c} **User No. 6** \\ **([PERSON])** \\ \end{tabular} \\ \hline \multicolumn{8}{c}{In daylight} \\ \hline [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\ B & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\ [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\ D & [PERSON] & [PERSON] & [PERSON] & [PERSON] & unknown & [PERSON] \\ [PERSON] & [PERSON] & unknown & [PERSON] & [PERSON] & unknown & [PERSON] \\ \hline \multicolumn{8}{c}{In artificial light} \\ \hline A & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\ B & [PERSON] & [PERSON] & [PERSON] & [PERSON] & unknown & [PERSON] \\ C & [PERSON] & [PERSON] & unknown & [PERSON] & [PERSON] & unknown \\ D & unknown & unknown & [PERSON] & [PERSON] & unknown & unknown \\ [PERSON] & [PERSON] & unknown & unknown & [PERSON] & [PERSON] & [PERSON] \\ \hline \multicolumn{8}{c}{In a darkened room} \\ \hline A & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\ B & [PERSON] & [PERSON] & unknown & unknown & unknown & [PERSON] \\ C & unknown & unknown & [PERSON] & unknown & [PERSON] & unknown \\ D & unknown & unknown & unknown & unknown & unknown & unknown \\ E & unknown & unknown & unknown & unknown & unknown & unknown \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Face recognition results with all users introduced into the system and with a constant similarity threshold of 85% (conditions for capturing the tested image: A—face in a frontal position; B—face in a left-side position; C—face in a right-side position; D—face in an upward position; E—face in a downward position). \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Attempt** & \begin{tabular}{c} **User No. 1** \\ **([PERSON])** \\ \end{tabular} & \begin{tabular}{c} **User No. 2** \\ **([PERSON])** \\ \end{tabular} & \begin{tabular}{c} **User No. 3** \\ **([PERSON])** \\ \end{tabular} & \begin{tabular}{c} **User No. 4** \\ **([PERSON])** \\ \end{tabular} & \
\begin{tabular}{c} **User No. 5** \\ **([PERSON])** \\ \end{tabular} &
\begin{tabular}{c} **User No. 6** \\ **([PERSON])** \\ \end{tabular} \\ \hline
1 & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\
2 & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\
3 & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] & [PERSON] \\ \multicolumn{8}{c}{Time in which the system recognized the user [s]} \\
1 & \(\sim\)12 & \(\sim\)12 & \(\sim\)16 & \(\sim\)9 & \(\sim\)15 & \(\sim\)12 \\
2 & \(\sim\)14 & \(\sim\)15 & \(\sim\)13 & \(\sim\)13 & \(\sim\)13 & \(\sim\)14 \\
3 & \(\sim\)12 & \(\sim\)11 & \(\sim\)15 & \(\sim\)12 & \(\sim\)10 & \(\sim\)14 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The face recognition results obtained with all users introduced into the system and the similarity threshold set at 85%. Each member of the sample group was positioned frontally to the camera. Upon initiating the process of capturing exemplary images, the user gradually moved their head to the left, then to the right, followed by upward and downward movements. Subsequently, the user altered their facial expressions to depict joy, sadness, or surprise.