“…The blossoming of the field and the variety of the proposed solutions raise the issue, for both researchers and practitioners, of a fair comparison among proposed techniques while engaging in the rapid prototyping and the systematic testing of novel methods. Under such circumstances, several reviews and surveys concerning rPPG ( McDuff et al, 2015 ; Rouast et al, 2018 ; Heusch, Anjos & Marcel, 2017a ; Unakafov, 2018 ; Wang et al, 2016 ; McDuff & Blackford, 2019 ; Cheng et al, 2021 ; McDuff, 2021 ; Ni, Azarang & Kehtarnavaz, 2021 ) have conducted empirical comparisons, albeit suffering under several aspects, as discussed in ‘Related Works’.…”