Diffusion-Phys: noise-robust heart rate estimation from facial videos via diffusion models

Remote photoplethysmography (rPPG) offers significant potential for health monitoring and emotional analysis through non-contact physiological measurement from facial videos. However, noise remains a crucial challenge, limiting the generalizability of current rPPG methods. This paper introduces Diffusion-Phys, a novel framework using diffusion models for robust heart rate (HR) estimation from facial videos. Diffusion-Phys employs Multi-scale Spatial-Temporal Maps (MSTmaps) to preprocess input data and introduces Gaussian noise to simulate real-world conditions. The model is trained using a denoising network for accurate HR estimation. Experimental evaluations on the VIPL-HR, UBFC-rPPG and PURE datasets demonstrate that Diffusion-Phys achieves comparable or superior performance to state-of-the-art methods, with lower computational complexity. These results highlight the effectiveness of explicitly addressing noise through diffusion modeling, improving the reliability and generalization of non-contact physiological measurement systems.