HandBooster+: Boosting 3D Hand-Mesh Reconstruction From Data Synthesis to Progressive Multi-Hypothesis Aggregation.

Robustly reconstructing 3D hand mesh from a single image is very challenging, due to (i) the lack of diversity in existing real-world datasets and (ii) the ambiguity in occluded hand regions. While data synthesis helps relieve issue (i), the syn-to-real gap still hinders its usage. For issue (ii), most previous works produce deterministic results while other probabilistic methods rely on ground truths to choose the best hypothesis. In this work, we explore the diffusion model to alleviate these problems by collectively considering two perspectives: (i) conditional synthesis and sampling approach for realistic data generation and (ii) probabilistic modeling with progressive multi-hypothesis aggregation. First, we present HandBooster, a new approach to uplift the data diversity by training a conditional generative space on hand-object interactions and sampling the space to synthesize effective data with reliable 3D annotations and diverse hand appearances, poses, views, and backgrounds. Second, we design HandBooster+, a probabilistic diffusion-based model to further boost the 3D hand-mesh reconstruction performance by progressively aggregating the multiple hypotheses. Extensive experimental results show that our method significantly improves several baselines and achieves SOTA on the HO3D and DexYCB benchmarks. Our code will be released on https: //github. com/hxwork/HandBooster+PyTorch.