Table 2.

Estimation of heart rates from the normal dataset without facial expressions and voluntary head motions.

Heart Rate Estimation	MAE	SDAE	RMSE	CC
Peak Detection	3.95	2.49	4.70	0.933 **
FFT	2.76	5.91	6.61	0.967 **
Clustering	1.07	0.99	1.47	0.999 **

MAE = mean absolute error; SDAE = standard deviation of absolute error; RMSE = root mean square error; CC = Pearson’s correlation coefficient. Two asterisk represents significant correlation levels at p-value < 0.01. The lowest error and highest correlation values are bolded.