Fig. 1. Absorption spectra of Hb and HbO₂

Fig. 2. Overall design of blood oxygen saturation measurement based on ICEEMDAN-WT

Fig. 3. Detection and tracking effect

Fig. 4. Skin segmentation effect

Fig. 5. B channel and R channel signals after pixel average

Fig. 6. B channel and R channel signals after removing DC

Fig. 7. B channel decomposed signal

Fig. 8. Spectral components of each mode of the B channel

Fig. 9. R channel decomposed signal

Fig. 10. Spectral components of each mode of the R channel

Fig. 11. Reconstructed signal of channel B

Fig. 12. Reconstructed signal of channel R

Fig. 13. Partial head movement frames

Fig. 14. Evaluation index comparison

Fig. 15. MAE comparison of different methods

Fig. 16. Bland-Altman scatter plot