| Citation: | LI Wen-tong, ZHANG Qi-qi, LIU Long-xin, MA Zhen-long, SUN Yun-jie, JI Xiao-qiang. Denoising of imaging photoplethysmography signals[J]. Chinese Optics. doi: 10.37188/CO.2025-0103 |
Image Photoplethysmography (IPPG) signals are easily disturbed by noise during acquisition. To address the issue, this study proposes a denoising diffusion probability model for IPPG (DDPM-IPPG). This model eliminates baseline drift and noise through diffusion and reverse diffusion stages, and improves the signal-to-noise ratio and heart rate accuracy. First, Gaussian noise is gradually added to the photoplethysmography (PPG) signal during the diffusion phase to create a noise sequence. A noise predictor based on a nonlinear fusion module and a bridging module is trained. Subsequently, in the reverse diffusion phase, the well-trained noise predictor is employed to perform step-by-step denoising on the initially extracted IPPG signal. Through this denoising, a signal with high signal-to-noise ratio is recovered. The model proposed in this paper is validated and compared with current mainstream algorithms on the PURE, UBFC-IPPG, UBFC-Phys, and MMPD datasets. The experimental results show that DDPM-IPPG improves the signal-to-noise ratio by 1.06 dB on the PURE dataset comparing with the existing highest-precision extraction method. The mean absolute error of heart rate decreases by 0.24 bpm. The root mean square error of heart rate decreases by 0.41 bpm. On the UBFC-IPPG dataset, the signal-to-noise ratio is improved by 1.50 dB. The proposed DDPM-IPPG model has achieved the current advanced level in eliminating baseline drift and noise from IPPG signals, enabling a more precise approximation of the true signals and providing a more reliable data foundation for physiological health assessment and telemedicine monitoring.
| [1] |
ZHANG X B, XIA ZH Q, DAI J, et al. MSDN: a multistage deep network for heart-rate estimation from facial videos[J]. IEEE Transactions on Instrumentation and Measurement, 2023, 72: 5032415.
|
| [2] |
TAO X, SU L W, RAO ZH, et al. Facial video-based non-contact emotion recognition: a multi-view features expression and fusion method[J]. Biomedical Signal Processing and Control, 2024, 96: 106608. doi: 10.1016/j.bspc.2024.106608
|
| [3] |
黄凯, 王峰, 王晔, 等. 基于颜色和光流的多注意力机制微表情识别[J]. 液晶与显示, 2024, 39(7): 939-949.
HUANG Kai, WANG Feng, WANG Ye, et al. Multi-attention micro-expression recognition based on color and optical flow[J]. Chinese Journal of Liquid Crystals and Displays, 2024, 39(7): 939-949. (in Chinese).
|
| [4] |
GUARDUCCI S, JAYOUSI S, CAPUTO S, et al. Key fundamentals and examples of sensors for human health: wearable, non-continuous, and non-contact monitoring devices[J]. Sensors, 2025, 25(2): 556. doi: 10.3390/s25020556
|
| [5] |
LEE R J, SIVAKUMAR S, LIM K H. Review on remote heart rate measurements using photoplethysmography[J]. Multimedia Tools and Applications, 2024, 83(15): 44699-44728.
|
| [6] |
PEREPELKINA O, ARTEMYEV M, CHURIKOVA M, et al. HeartTrack: convolutional neural network for remote video-based heart rate monitoring[C]. 2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops (CVPRW), IEEE, 2020: 1163-1171.
|
| [7] |
YU Z T, PENG W, LI X B, et al. Remote heart rate measurement from highly compressed facial videos: an end-to-end deep learning solution with video enhancement[C]. 2019 IEEE/CVF International Conference on Computer Vision (ICCV), IEEE, 2019: 151-160.
|
| [8] |
CASADO C Á, LÓPEZ M B. Face2PPG: an unsupervised pipeline for blood volume pulse extraction from faces[J]. IEEE Journal of Biomedical and Health Informatics, 2023, 27(11): 5530-5541. doi: 10.1109/JBHI.2023.3307942
|
| [9] |
ALNAGGAR M, SIAM A I, HANDOSA M, et al. Video-based real-time monitoring for heart rate and respiration rate[J]. Expert Systems with Applications, 2023, 225: 120135. doi: 10.1016/j.eswa.2023.120135
|
| [10] |
ZOU B CH, GUO Z ZH, HU X CH, et al. RhythmMamba: fast, lightweight, and accurate remote physiological measurement[C]. Proceedings of the 39th AAAI Conference on Artificial Intelligence, AAAI Press, 2025: 11077-11085.
|
| [11] |
WU B W, JIANG T, YU ZH X, et al. Proximity sensing electronic skin: principles, characteristics, and applications[J]. Advanced Science, 2024, 11(13): 2308560. doi: 10.1002/advs.202308560
|
| [12] |
饶治, 李炳霖, 隋雅茹, 等. 成像式光体积描记术精神压力检测[J]. 中国光学(中英文), 2022, 15(6): 1350-1359.
RAO ZH, LI B L, SUI Y R, et al. Image photoplethysmography for mental stress detection[J]. Chinese Optics, 2022, 15(6): 1350-1359. (in Chinese).
|
| [13] |
嵇晓强, 刘振瑶, 李炳霖, 等. 面部视频非接触式生理参数感知[J]. 中国光学, 2022, 15(2): 276-285. doi: 10.37188/CO.2021-0157
JI X Q, LIU ZH Y, LI B L, et al. Non-contact perception of physiological parameters from videos of faces[J]. Chinese Optics, 2022, 15(2): 276-285. (in Chinese). doi: 10.37188/CO.2021-0157
|
| [14] |
CASADO C Á, CAÑELLAS M L, LÓPEZ M B. Depression recognition using remote photoplethysmography from facial videos[J]. IEEE Transactions on Affective Computing, 2023, 14(4): 3305-3316. doi: 10.1109/TAFFC.2023.3238641
|
| [15] |
ANIL A A, KARTHIK S, SIVAPRAKASAM M, et al. Dynamic ROI adaptation for accurate non-contact heart rate estimation using VGG-13 based encoder-decoder model and facial landmarks[C]. ICASSP 2025 - 2025 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), IEEE, 2025: 1-5.
|
| [16] |
POH M Z, MCDUFF D J, PICARD R W. Advancements in noncontact, multiparameter physiological measurements using a webcam[J]. IEEE Transactions on Biomedical Engineering, 2011, 58(1): 7-11. doi: 10.1109/TBME.2010.2086456
|
| [17] |
DE HAAN G, JEANNE V. Robust pulse rate from chrominance-based rPPG[J]. IEEE Transactions on Biomedical Engineering, 2013, 60(10): 2878-2886. doi: 10.1109/TBME.2013.2266196
|
| [18] |
WANG W J, DEN BRINKER A C, STUIJK S, et al. Algorithmic principles of remote PPG[J]. IEEE Transactions on Biomedical Engineering, 2017, 64(7): 1479-1491. doi: 10.1109/TBME.2016.2609282
|
| [19] |
陈森路, 刘育梁, 徐团伟. 基于自适应感兴趣区域的视频心率测量[J]. 光学精密工程, 2021, 29(7): 1740-1749.
CHEN Sen-lu, LIU Yu-liang, XU Tuan-wei. Video heart rate measurements based on adaptive region of interest[J]. Optics and Precision Engineering, 2021, 29(7): 1740-1749. (in Chinese).
|
| [20] |
CHEN W X, MCDUFF D. DeepPhys: video-based physiological measurement using convolutional attention networks[C]. Proceedings of the 15th European Conference on Computer Vision - ECCV 2018, Springer, 2018: 356-373.
|
| [21] |
LIU X, FROMM J, PATEL S, et al. Multi-task temporal shift attention networks for on-device contactless vitals measurement[C]. Proceedings of the 34th International Conference on Neural Information Processing Systems, Curran Associates Inc., 2020: 1627.
|
| [22] |
LIU X, HILL B, JIANG Z H, et al. EfficientPhys: enabling simple, fast and accurate camera-based cardiac measurement[C]. 2023 IEEE/CVF Winter Conference on Applications of Computer Vision (WACV), IEEE, 2023: 4997-5006.
|
| [23] |
YU Z T, SHEN Y M, SHI J G, et al. PhysFormer: facial video-based physiological measurement with temporal difference transformer[C]. 2022 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), IEEE, 2022: 4176-4186.
|
| [24] |
YU Z T, LI X B, ZHAO G Y. Remote photoplethysmograph signal measurement from facial videos using spatio-temporal networks[C]. Proceedings of the 30th British Machine Vision Conference 2019, BWVA Press, 2019: 277.
|
| [25] |
ZOU B CH, GUO Z ZH, CHEN J SH, et al. RhythmFormer: extracting patterned rPPG signals based on periodic sparse attention[J]. Pattern Recognition, 2025, 164: 111511. doi: 10.1016/j.patcog.2025.111511
|
| [26] |
KUANG H L, LV F B, MA X L, et al. Efficient spatiotemporal attention network for remote heart rate variability analysis[J]. Sensors, 2022, 22(3): 1010. doi: 10.3390/s22031010
|
| [27] |
LIU X, ZHANG Y T, YU Z T, et al. rPPG-MAE: self-supervised pretraining with masked autoencoders for remote physiological measurements[J]. IEEE Transactions on Multimedia, 2024, 26: 7278-7293. doi: 10.1109/TMM.2024.3363660
|
| [28] |
SPETH J, VANCE N, FLYNN P, et al. Non-contrastive unsupervised learning of physiological signals from video[C]. 2023 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), IEEE, 2023: 14464-14474.
|
| [29] |
SONG R CH, CHEN H, CHENG J, et al. PulseGAN: learning to generate realistic pulse waveforms in remote photoplethysmography[J]. IEEE Journal of Biomedical and Health Informatics, 2021, 25(5): 1373-1384. doi: 10.1109/JBHI.2021.3051176
|
| [30] |
CHEN SH T, WONG K L, CHIN J W, et al. DiffPhys: enhancing signal-to-noise ratio in remote photoplethysmography signal using a diffusion model approach[J]. Bioengineering, 2024, 11(8): 743. doi: 10.3390/bioengineering11080743
|
| [31] |
LI ZH P, XIAO H G, XIA Z Y, et al. STFPNet: a simple temporal feature pyramid network for remote heart rate measurement[J]. Measurement, 2025, 252: 117287. doi: 10.1016/j.measurement.2025.117287
|
| [32] |
HUANG B, HU SH, LIU Z M, et al. Challenges and prospects of visual contactless physiological monitoring in clinical study[J]. npj Digital Medicine, 2023, 6(1): 231. doi: 10.1038/s41746-023-00973-x
|
| [33] |
LUGARESI C, TANG J Q, NASH H, et al. MediaPipe: a framework for building perception pipelines[J]. arXiv:, 1906, 08172: 2019.
|
| [34] |
HO J, JAIN A, ABBEEL P. Denoising diffusion probabilistic models[C]. Proceedings of the 34th International Conference on Neural Information Processing Systems, Curran Associates Inc., 2020: 574.
|
| [35] |
SOHL-DICKSTEIN J, WEISS E A, MAHESWARANATHAN N, et al. Deep unsupervised learning using nonequilibrium thermodynamics[C]. Proceedings of the 32nd International Conference on Machine Learning, JMLR. org, 2015: 2256-2265.
|
| [36] |
STRICKER R, MÜLLER S, GROSS H M. Non-contact video-based pulse rate measurement on a mobile service robot[C]. Proceedings of the 23rd IEEE International Symposium on Robot and Human Interactive Communication, IEEE, 2014: 1056-1062.
|
| [37] |
BOBBIA S, MACWAN R, BENEZETH Y, et al. Unsupervised skin tissue segmentation for remote photoplethysmography[J]. Pattern Recognition Letters, 2019, 124: 82-90. doi: 10.1016/j.patrec.2017.10.017
|
| [38] |
TANG J K, CHEN K Q, WANG Y T, et al. MMPD: multi-domain mobile video physiology dataset[C]. 2023 45th Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), IEEE, 2023: 1-5.
|
| [39] |
SABOUR R M, BENEZETH Y, DE OLIVEIRA P, et al. UBFC-Phys: a multimodal database for psychophysiological studies of social stress[J]. IEEE Transactions on Affective Computing, 2023, 14(1): 622-636. doi: 10.1109/TAFFC.2021.3056960
|
| [40] |
VERKRUYSSE W, SVAASAND L O, NELSON J S. Remote plethysmographic imaging using ambient light[J]. Optics Express, 2008, 16(26): 21434-21445. doi: 10.1364/OE.16.021434
|
| [41] |
PILZ C S, ZAUNSEDER S, KRAJEWSKI J, et al. Local group invariance for heart rate estimation from face videos in the wild[C]. 2018 IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops (CVPRW), IEEE, 2018: 1254-1262.
|
| [42] |
DE HAAN G, VAN LEEST A. Improved motion robustness of remote-PPG by using the blood volume pulse signature[J]. Physiological Measurement, 2014, 35(9): 1913-1926. doi: 10.1088/0967-3334/35/9/1913
|