111 research outputs found
SHERF: Generalizable Human NeRF from a Single Image
Existing Human NeRF methods for reconstructing 3D humans typically rely on
multiple 2D images from multi-view cameras or monocular videos captured from
fixed camera views. However, in real-world scenarios, human images are often
captured from random camera angles, presenting challenges for high-quality 3D
human reconstruction. In this paper, we propose SHERF, the first generalizable
Human NeRF model for recovering animatable 3D humans from a single input image.
SHERF extracts and encodes 3D human representations in canonical space,
enabling rendering and animation from free views and poses. To achieve
high-fidelity novel view and pose synthesis, the encoded 3D human
representations should capture both global appearance and local fine-grained
textures. To this end, we propose a bank of 3D-aware hierarchical features,
including global, point-level, and pixel-aligned features, to facilitate
informative encoding. Global features enhance the information extracted from
the single input image and complement the information missing from the partial
2D observation. Point-level features provide strong clues of 3D human
structure, while pixel-aligned features preserve more fine-grained details. To
effectively integrate the 3D-aware hierarchical feature bank, we design a
feature fusion transformer. Extensive experiments on THuman, RenderPeople,
ZJU_MoCap, and HuMMan datasets demonstrate that SHERF achieves state-of-the-art
performance, with better generalizability for novel view and pose synthesis.Comment: Accepted by ICCV2023. Project webpage:
https://skhu101.github.io/SHERF
OCC-VO: Dense Mapping via 3D Occupancy-Based Visual Odometry for Autonomous Driving
Visual Odometry (VO) plays a pivotal role in autonomous systems, with a
principal challenge being the lack of depth information in camera images. This
paper introduces OCC-VO, a novel framework that capitalizes on recent advances
in deep learning to transform 2D camera images into 3D semantic occupancy,
thereby circumventing the traditional need for concurrent estimation of ego
poses and landmark locations. Within this framework, we utilize the TPV-Former
to convert surround view cameras' images into 3D semantic occupancy. Addressing
the challenges presented by this transformation, we have specifically tailored
a pose estimation and mapping algorithm that incorporates Semantic Label
Filter, Dynamic Object Filter, and finally, utilizes Voxel PFilter for
maintaining a consistent global semantic map. Evaluations on the Occ3D-nuScenes
not only showcase a 20.6% improvement in Success Ratio and a 29.6% enhancement
in trajectory accuracy against ORB-SLAM3, but also emphasize our ability to
construct a comprehensive map. Our implementation is open-sourced and available
at: https://github.com/USTCLH/OCC-VO.Comment: 7pages, 3 figure
Femtosecond Laser Filamentation in Atmospheric Turbulence
The effects of turbulence intensity and turbulence region on the distribution
of femtosecond laser filaments are experimentally elaborated. Through the
ultrasonic signals emitted by the filaments, and it is observed that increasing
turbulence intensity and expanding turbulence active region cause an increase
in the start position of the filament, and a decrease in filament length, which
can be well explained by the theoretical calculation. It is also observed that
the random perturbation of the air refractive index caused by atmospheric
turbulence expanded the spot size of the filament. Additionally, when
turbulence intensity reaches , multiple filaments are formed. Furthermore, the
standard deviation of the transverse displacement of filament is found to be
proportional to the square root of turbulent structure constant under the
experimental turbulence parameters in this paper. These results contribute to
the study of femtosecond laser propagation mechanisms in complex atmospheric
turbulence conditionsComment: 9 pages, 4 figure
Preparation of Copper Oxide/TiO2 Composite Films by Mechanical Ball Milling and Investigated Photocatalytic Activity
The Cu/Ti composite coatings were prepared by the mechanical ball milling, the CuO/TiO2 and Cu2O/TiO2 composite photocatalytic films were obtained by the subsequent oxidation process. The microstructure of the composite films was analyzed by X-ray Diffraction (XRD)and scanning election microscope (SEM). The photocatalytic activity was evaluated, the effects of ball milling time on the formation of the Cu/Ti coatings were investigated, and the effects of the oxidation temperature and oxidation atmosphere on microstructure and photocatalytic activity of the films were studied. The results illustrate that the ball milling time has significant effects on the formation of the coatings and the coatings are continuous and compact by ball milling for 15 h. The photocatalytic activity of the CuO/TiO2 composite films is increased first and then decreased with the oxidation temperature increases, and the photocatalytic activity is the best at 500 °C. The CuO/TiO2 composite films are obtained by the oxidation of Cu/Ti coatings at 500 °C for 15 h in the air, while the Cu2O/TiO2 composite films are oxidized in carbon atmosphere. Photocatalysis efficiency of the films is obviously enhanced with the help of the p-n junction heterostructure in the Cu2O/TiO2 composite films
Exogenous melatonin mediates radish (Raphanus sativus) and Alternaria brassicae interaction in a dose-dependent manner
Radish (Raphanus sativus L.) is an economically important vegetable worldwide, but its sustainable production and breeding are highly threatened by blight disease caused by Alternaria brassicae. Melatonin is an important growth regulator that can influence physiological activities in both plants and microbes and stimulate biotic stress resistance in plants. In this study, 0-1500 μM melatonin was exogenously applied to healthy radish seedlings, in vitro incubated A. brassicae, and diseased radish seedlings to determine the effects of melatonin on host, pathogen, and host-pathogen interaction. At sufficient concentrations (0-500 μM), melatonin enhanced growth and immunity of healthy radish seedlings by improving the function of organelles and promoting the biosynthesis of antioxidant enzymes, chitin, organic acid, and defense proteins. Interestingly, melatonin also improved colony growth, development, and virulence of A. brassicae. A strong dosage-dependent effect of melatonin was observed: 50-500 μM promoted host and pathogen vitality and resistance (500 μM was optimal) and 1500 μM inhibited these processes. Significantly less blight was observed on diseased seedlings treated with 500 μM melatonin, indicating that melatonin more strongly enhanced the growth and immunity of radish than it promoted the development and virulence of A. brassicae at this treatment concentration. These effects of MT were mediated by transcriptional changes of key genes as identified by RNA-seq, Dual RNA-seq, and qRT-PCR. The results from this work provide a theoretical basis for the application of melatonin to protect vegetable crops against pathogens
SynBody: Synthetic Dataset with Layered Human Models for 3D Human Perception and Modeling
Synthetic data has emerged as a promising source for 3D human research as it
offers low-cost access to large-scale human datasets. To advance the diversity
and annotation quality of human models, we introduce a new synthetic dataset,
SynBody, with three appealing features: 1) a clothed parametric human model
that can generate a diverse range of subjects; 2) the layered human
representation that naturally offers high-quality 3D annotations to support
multiple tasks; 3) a scalable system for producing realistic data to facilitate
real-world tasks. The dataset comprises 1.2M images with corresponding accurate
3D annotations, covering 10,000 human body models, 1,187 actions, and various
viewpoints. The dataset includes two subsets for human pose and shape
estimation as well as human neural rendering. Extensive experiments on SynBody
indicate that it substantially enhances both SMPL and SMPL-X estimation.
Furthermore, the incorporation of layered annotations offers a valuable
training resource for investigating the Human Neural Radiance Fields (NeRF).Comment: Accepted by ICCV 2023. Project webpage: https://synbody.github.io
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