## 3 Different Aspects of Colour-Based Method
### Alternate Sensors
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Ref.**} & \multirow{2}{*}{**Used Sensors with Parameter**} & \multirow{2}{*}{**Vial Signs**} & \multirow{2}{*}{**ROIs**} & \multirow{2}{*}{**Used Technique**} & \multirow{2}{*}{**Distance (m)**} & \multicolumn{2}{c}{**No.of**} \\  & & & & & & & **Participants at a** & **Results** \\ \hline [PERSON] et al. [101] & Smartphone resolution 640\(\times\) 480, 30 fps & HR & Face & ICA & 0.3 m & 1 & MAE = 1.47 ppm \\ \hline [PERSON] et al. [102] & UAV resolution 380\(\times\) 2160, 25 fps & HR and ER & Face & CESMD + ICA & 3 m & 1 & PCC = 0.99, RMSE = 0.7 ppm \\ \hline [PERSON] et al. [100] & Digital cameras with five hands resolution & HR, RR, and HRV & Face & ICA & 3 m & 1 & PCC = 0.92 \\ \hline [PERSON] et al. [200] & CMOS resolution 1280\(\times\) 1024, Webcam & HR & Face & TPR & 0.2-0.35 m & 1 & PCC = 0.85 \\ \hline [PERSON] et al. [100] & Microsoft Kinect 300 ps & HR and ER & Neck, thousands and abdominal area & ICA & - & 1 & PCC = 0.91 \\ \hline [PERSON] et al. [100] & Microsoft Kinect & HR & Face & & & & 1 & - \\ \hline [PERSON] et al. [101] & Member Kinect resolution 1020\(\times\) 2800, 30 fps & HR & Feedback, checks, & EVM & - & 1 & RMSE = 2.22 ppm \\ \hline [PERSON] et al. [100] & Webcam resolution 640\(\times\) 480, 30 fps & HR & Feedback & ICA & 20.0 cm & 1 & PCC = 0.94 \\ \hline [PERSON] et al. [101] & Digital cameras 300\(\times\) 300 face detector, 15 fps & HR & Face and check & JFTD & 1 m & 1 & - \\ \hline [PERSON] et al. [100] & Digital cameras resolution 1920\(\times\) 1080 or & HR & Abdominal area & Stack FIFO & 50.0 cm & 1 & PCC = 0.94 \\ \hline [PERSON] et al. [101] & Digital camera camera resolution 1920\(\times\) 1080, 30 fps & HR and RR & Face and chest & EVM & 1-2 m & 1 & Mean bias = 4.5 ppm \\ \hline [PERSON] [111] & Webcam resolution 640\(\times\) 480, 30 fps & HR and SP\({}_{2}\) & Face & DTCWT & 50.0 cm & 1 & PCC = 0.92, RMSE = 2.05 ppm \\ \hline [PERSON] et al. [92] & Digital cameras resolution 5 megribribers, 12 fps & HR, RR, SP\({}_{2}\) & Fowhead and check & AR modelling and pole cancellation & 1 m & 1 & MAE = 3 ppm \\ \hline [PERSON] et al. [112] & Webcam resolution 640\(\times\) 480, 30 fps & HR & Face and checks & ICA & 1-2 m & 1 & RMSE = 2.7 ppm \\ \hline [PERSON] et al. [113] & Video cameras resolution 252\(\times\) 350, 15 fps & HR & 10 different parts of & ICA & - & 1 & RMSE = 1.47 ppm \\ \hline [PERSON] et al. [114] & Webcam resolution 640\(\times\) 480, 30 fps & HR & Face and palm & Block division & 0.75 m & 1 & PCC = 0.96 \\ \hline [PERSON] et al. [115] & Webcam resolution 640\(\times\) 480, 30 fps & HR & Face, arm, hand & POSCC & 1.5 m & 2 & SNR (dB) = 4.5 \\ \hline [PERSON] et al. [116] & Digital cameras resolution 1920\(\times\) 1080 or & HR & FR, palm, wrist, arm, and neck, fire, forehead, head and chest & EMD + ICA & 2 m & 1 & PCC = 0.96, RMSE = 3.52 \\ \hline [PERSON] et al. [117] & Digital camera resolution 160\(\times\) 720, 60 fps & HR and RR & Face and Forehead & \begin{tabular}{c} CESMDAN + \\ CCA \\ \end{tabular} & 60 m & 6 & PCC = 0.99, RMSE = 0.89 ppm \\ \hline [PERSON] et al. [118] & Video camera resolution 1920\(\times\) 1080, 29.57 fps & HR & Face & SVR & - & 1 & PCC = 0.88, RMSE = 5.88 ppm \\ \hline [PERSON] et al. [119] & Video camera resolution 658 \(\times\) 492, 120 fps & HR and BR & Face & \
\begin{tabular}{c} Convolutional \\ attention network \\ \end{tabular} & - & 1 & 1 & MAE = 1.50 ppm \\ \hline [PERSON] et al. [120] & Video-camera resolution 1920\(\times\) 2808, 60 fps & HR and HRV & Face &
\begin{tabular}{c} Spatio-temporal \\ network \\ \end{tabular} & - & 1 & PCC = 0.99, RMSE = 1.8 ppm \\ \hline [PERSON] et al. [212] & Industrial cameras & HR & Feedback & ICA & 2 m & 1 & RMSE + 4.83 ppm \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Summary of different iPPG based methods.