Human as Points: Explicit Point-Based 3D Human Reconstruction From Single-View RGB Images

The latest trends in the research field of single-view human reconstruction are devoted to learning deep implicit functions constrained by explicit body shape priors. Despite the remarkable performance improvements compared with traditional processing pipelines, existing learning approaches still exhibit limitations in terms of flexibility, generalizability, robustness, and/or representation capability. To comprehensively address the above issues, in this paper, we investigate an explicit point-based human reconstruction framework named HaP, which utilizes point clouds as the intermediate representation of the target geometric structure. Technically, our approach features fully explicit point cloud estimation (exploiting depth and SMPL), manipulation (SMPL rectification), generation (built upon diffusion), and refinement (displacement learning and depth replacement) in the 3D geometric space, instead of an implicit learning process that can be ambiguous and less controllable. Extensive experiments demonstrate that our framework achieves quantitative performance improvements of 20$\%$ to 40$\%$ over current state-of-the-art methods, and better qualitative results. Our promising results may indicate a paradigm rollback to the fully-explicit and geometry-centric algorithm design. In addition, we newly contribute a real-scanned 3D human dataset featuring more intricate geometric details.