Talking Head Generation via Viewpoint and Lighting Simulation Based on Global Representation

NeRF-based talking head generation has made great progress, but existing methods still lack in achieving high-quality detail fidelity, mainly manifested in detail loss and intermittent blur. We attribute this to the limitations of the training video data in terms of viewpoint and lighting, which leads to the inability to fully model the global depth and brightness information of spatial points. Specifically, a fixed viewpoint may fail to provide sufficient depth information for high-frequency details, leading to inaccurate volume density estimation and the loss of details such as hair. Furthermore, constant lighting often fails to adapt to the drastic brightness changes of continuous video frames, resulting in color accumulation errors and blurring artifacts. To address these issues, we propose a novel talking head generation method that combines layered viewpoint simulation (LVS) and continuous lighting simulation (CLS). LVS simulates multiple viewpoints through the multi-scale features of the video frame to construct the global depth representation, which can improve the accuracy of volume density estimation and enhance detail description. CLS simulates multiple lighting through brightness changes of continuous video frames to construct the global brightness representation, thereby alleviating color accumulation errors and eliminating blur. Extensive experiments demonstrate that our method significantly improves the detail quality compared to the state-of-the-art methods.