Figure 1.
Schematic overview of the RR algorithm. (a) Selection of region of interest (ROI); (b) Detection and tracking of feature points; (c) Extraction of feature points’ trajectories; (d) Temporal filtering; (e) Blind source separation via principal component analysis (PCA); (f) Rank principal components (PCs) based on their variance; (g) Computation of frequency spectra and estimation of RR.