SeIF: Semantic-Constrained Deep Implicit Function for Single-Image 3D Head Reconstruction

Various applications require realistic, artifact-free, and animatable 3D avatars. However, traditional 3D morphable models (3DMMs) produce animatable 3D heads but fail to capture accurate geometries and details, while existing deep implicit functions have been shown to achieve realistic reconstructions but suffer from artifacts and struggle to yield 3D heads that are easy to animate. To reconstruct high-fidelity, artifact-less, and animatable 3D heads from single-view images, we leverage semantics to bridge the best properties of 3DMMs and deep implicit functions and propose SeIF-a semantic-constrained deep implicit function. First, SeIF derives fine-grained semantics from a standard 3DMM (e.g., FLAME) and samples a semantic code for each query point in the query space to provide a soft constraint to the deep implicit function. The reconstruction results show that this semantic constraint does not weaken the powerful representation ability of the deep implicit function while significantly suppressing artifacts. Second, SeIF predicts a more accurate semantic code for each query point and utilizes the semantic codes to uniformize the structure of reconstructed 3D head meshes with the standard 3DMM. Since our reconstructed 3D head meshes have the same structure as the 3DMM, 3DMM-based animation approaches can be easily transferred to animate our reconstructed 3D heads. As a result, SeIF can reconstruct high-fidelity, artifact-less, and animatable 3D heads from single-view images of individuals with diverse ages, genders, races, and facial expressions. Quantitative and qualitative experimental results on seven datasets show that SeIF outperforms existing state-of-the-art methods by a large margin.