RhythmGuassian: Repurposing Generalizable Gaussian Model For Remote Physiological Measurement

Remote Photoplethysmography (rPPG) enables non-contact extraction of physiological signals, providing significant advantages in medical monitoring, emotion recognition, and face anti-spoofing. However, the extraction of reliable rPPG signals is hindered by motion variations in real-world environments, leading to entanglement issue. To address the challenge, we employ the Generalizable Gaussian Model (GGM) to disentangle geometry and chroma components with 4D Gaussian representations. Employing the GGM for robust rPPG estimation is non-trivial. Firstly, there are no camera parameters in the dataset, resulting in the inability to render video from 4D Gaussian. The ``4D virtual camera'' is proposed to construct extra Gaussian parameters to describe view and motion changes, giving the ability to render video with the fixed virtual camera parameters. Further, the chroma component is still not explicitly decoupled in 4D Gaussian representation. Explicit motion modeling (EMM) is designed to decouple the motion variation in an unsupervised manner. Explicit chroma modeling (ECM) is tailored to decouple specular, physiological, and noise signals, respectively. To validate our approach, we expand existing rPPG datasets to include various motion and illumination interference scenarios, demonstrating the effectiveness of our method in real-world settings. The code will be available after acceptance.