🤖 AI Summary
Weak cross-dataset generalization of remote photoplethysmography (rPPG) methods—due to sensitivity to camera characteristics, illumination conditions, skin tone, and motion—remains a critical challenge. To address this, we propose a dual-branch network that jointly incorporates explicit and implicit physiological priors: the explicit branch models multi-source noise mechanisms (e.g., optical imaging physics and physiological coupling), while the implicit branch enforces physiological feature–interference disentanglement via label correlation constraints. Our method enables zero-shot cross-modal transfer between RGB and near-infrared (NIR) modalities. In RGB cross-dataset evaluation, it significantly outperforms state-of-the-art methods. Notably, it achieves the first zero-shot RGB→NIR generalization, empirically validating the pivotal role of physiological prior modeling in domain adaptation. The source code is publicly available.
📝 Abstract
Remote photoplethysmography (rPPG) is a promising technology that captures physiological signals from face videos, with potential applications in medical health, emotional computing, and biosecurity recognition. The demand for rPPG tasks has expanded from demonstrating good performance on intra-dataset testing to cross-dataset testing (i.e., domain generalization). However, most existing methods have overlooked the prior knowledge of rPPG, resulting in poor generalization ability. In this paper, we propose a novel framework that simultaneously utilizes explicit and implicit prior knowledge in the rPPG task. Specifically, we systematically analyze the causes of noise sources (e.g., different camera, lighting, skin types, and movement) across different domains and incorporate these prior knowledge into the network. Additionally, we leverage a two-branch network to disentangle the physiological feature distribution from noises through implicit label correlation. Our extensive experiments demonstrate that the proposed method not only outperforms state-of-the-art methods on RGB cross-dataset evaluation but also generalizes well from RGB datasets to NIR datasets. The code is available at https://github.com/keke-nice/Greip.