https://scholar.dgist.ac.kr/handle/20.500.11750/56971 2026-04-06T21:04:50Z https://scholar.dgist.ac.kr/handle/20.500.11750/57580 Title: Expressive Whole-Body 3D Gaussian Avatar Author(s): Moon, Gyeongsik; Shiratori, Takaaki; Saito, Shunsuke Abstract: Facial expression and hand motions are necessary to express our emotions and interact with the world. Nevertheless, most of the 3D human avatars modeled from a casually captured video only support body motions without facial expressions and hand motions. In this work, we present ExAvatar, an expressive whole-body 3D human avatar learned from a short monocular video. We design ExAvatar as a combination of the whole-body parametric mesh model (SMPL-X) and 3D Gaussian Splatting (3DGS). The main challenges are 1) a limited diversity of facial expressions and poses in the video and 2) the absence of 3D observations, such as 3D scans and RGBD images. The limited diversity in the video makes animations with novel facial expressions and poses non-trivial. In addition, the absence of 3D observations could cause significant ambiguity in human parts that are not observed in the video, which can result in noticeable artifacts under novel motions. To address them, we introduce our hybrid representation of the mesh and 3D Gaussians. Our hybrid representation treats each 3D Gaussian as a vertex on the surface with pre-defined connectivity information (i.e., triangle faces) between them following the mesh topology of SMPL-X. It makes our ExAvatar animatable with novel facial expressions by driven by the facial expression space of SMPL-X. In addition, by using connectivity-based regularizers, we significantly reduce artifacts in novel facial expressions and poses. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025. 2024-10-03T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57549 Title: 3D Hand Sequence Recovery from Real Blurry Images and Event Stream Author(s): Park, Joonkyu; Moon, Gyeongsik; Xu, Weipeng; Kaseman, Evan; Shiratori, Takaaki; Lee, Kyoung Mu Abstract: Although hands frequently exhibit motion blur due to their dynamic nature, existing approaches for 3D hand recovery often disregard the impact of motion blur in hand images. Blurry hand images contain hands from multiple time steps, lack precise hand location at a specific time step, and introduce temporal ambiguity, leading to multiple possible hand trajectories. To address this issue and in the absence of datasets with real blur, we introduce the EBH dataset, which provides 1) hand images with real motion blur and 2) event data for authentic representation of fast hand movements. In conjunction with our new dataset, we present EBHNet, a novel network capable of recovering 3D hands from diverse input combinations, including blurry hand images, events, or both. Here, the event stream enhances motion understanding in blurry hands, addressing temporal ambiguity. Recognizing that blurry hand images include not only single 3D hands at a time step but also multiple hands along their motion trajectories, we design EBHNet to generate 3D hand sequences in motion. Moreover, to enable our EBHNet to predict 3D hands at novel, unsupervised time steps using a single shared module, we employ a Transformer-based module, temporal splitter, into EBHNet. Our experiments show the superior performance of EBH and EBHNet, especially in handling blurry hand images, making them valuable in real-world applications. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025. 2024-09-30T15:00:00Z