SRFlow: A Dataset and Regularization Model for High-Resolution Facial Optical Flow via Splatting Rasterization
JiaLin Zhang, Dong Li
TL;DR
SRFlow introduces a high-resolution facial optical flow dataset built from a dynamic 3D Gaussian avatar and a Flow Rasterizer, enabling dense, structurally consistent supervision for motion. SRFlowNet adopts a backbone selected for subtle facial motion and integrates four regularization losses (TVR, FDR, MIGAR, IGVAR) to suppress noise while preserving fine-grained movement, achieving improved EPE and micro-expression recognition metrics. Training on SRFlow yields substantial gains across optical flow models and ups performance on micro-expression benchmarks, with up to 42% reduction in EPE and up to 48% improvement in macro F1 on a composite micro-expression dataset. Together, the dataset and regularized model demonstrate that high-resolution facial flow supervision can substantially enhance both low-level motion estimation and downstream expressive understanding in real-world scenarios.
Abstract
Facial optical flow supports a wide range of tasks in facial motion analysis. However, the lack of high-resolution facial optical flow datasets has hindered progress in this area. In this paper, we introduce Splatting Rasterization Flow (SRFlow), a high-resolution facial optical flow dataset, and Splatting Rasterization Guided FlowNet (SRFlowNet), a facial optical flow model with tailored regularization losses. These losses constrain flow predictions using masks and gradients computed via difference or Sobel operator. This effectively suppresses high-frequency noise and large-scale errors in texture-less or repetitive-pattern regions, enabling SRFlowNet to be the first model explicitly capable of capturing high-resolution skin motion guided by Gaussian splatting rasterization. Experiments show that training with the SRFlow dataset improves facial optical flow estimation across various optical flow models, reducing end-point error (EPE) by up to 42% (from 0.5081 to 0.2953). Furthermore, when coupled with the SRFlow dataset, SRFlowNet achieves up to a 48% improvement in F1-score (from 0.4733 to 0.6947) on a composite of three micro-expression datasets. These results demonstrate the value of advancing both facial optical flow estimation and micro-expression recognition.
