ANIM: Accurate Neural Implicit Model for Human Reconstruction from a single RGB-D image


ANIM Reconstruction Example
ANIM-Real data
Abstract

Recent progress in human shape learning shows that neural implicit models are effective in generating 3D human surfaces from a limited number of views, and even from a single RGB image. However, existing monocular approaches still struggle to recover fine geometric details such as face, hands or cloth wrinkles. They are also easily prone to depth ambiguities that result in distorted geometries along the camera's optical axis. In this paper, we explore the benefits of incorporating depth observations in the reconstruction process by introducing ANIM, a novel method that reconstructs arbitrary 3D human shapes from single-view RGB-D images with an unprecedented level of accuracy. Our model learns geometric details from both multi-resolution pixel-aligned and voxel-aligned features to leverage depth information and enable spatial relationships, mitigating depth ambiguities. We further enhance the quality of the reconstructed shape by introducing a depth-supervision strategy, which improves the accuracy of the signed distance field estimation of points that lie on the reconstructed surface. Experiments demonstrate that ANIM outperforms state-of-the-art works that use RGB, surface normals, point cloud or RGB-D data as input. In addition, we introduce ANIM-Real, a new multi-modal dataset comprising high-quality scans paired with consumer-grade RGB-D camera, and our protocol to fine-tune ANIM, enabling high-quality reconstruction from real-world human capture.
ANIM Approach

 
 
Our proposed framework has three major components: i) a multi-resolution appearance feature extractor for color and normal inputs (LR-FE and HR-FE), ii) a novel SparseConvNet U-Net (Volume Feature Extractor or VFE) that efficiently extracts geometry features from 3D voxels and low-resolution image features, iii) an MLP that estimate the implicit surface representation of full-body humans.
Paper

Citation

M. Pesavento, Y. Xu, N. Sarafianos, R. Maier, Z. Wang, C. Yao, M. Volino, E. Boyer, A. Hilton and T. Tung, "ANIM: Accurate Neural Implicit Model for Human Reconstruction from a single RGB-D image", The IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR), 2024.

Bibtex
@misc{pesavento2024anim,
      title={ANIM: Accurate Neural Implicit Model for Human Reconstruction from a single RGB-D image}, 
      author={Marco Pesavento and Yuanlu Xu and Nikolaos Sarafianos and Robert Maier and Ziyan Wang and Chun-Han Yao and Marco Volino and Edmond Boyer and Adrian Hilton and Tony Tung},
      year={2024},
      eprint={2403.10357},
      archivePrefix={arXiv},
      primaryClass={cs.CV}
}
        
Results

Quantitative Comparisons

Quantitative comparisons with state-of-the-art approaches in 3D human reconstruction from a single input.
Qualitative Comparisons

Qualitative comparisons with state-of-the-art approaches in 3D human reconstruction from a single RGB-D data.
Qualitative comparisons with state-of-the-art approaches in 3D human reconstruction from different kinds of input.
Real Data

Results obtained with real data from Azure-Kinect after fine-tuning ANIM with ANIM-Real
Acknowledgement

This research was supported by Meta, UKRI EPSRC and BBC Prosperity Partnership AI4ME: Future Personalised Object-Based Media Experiences Delivered at Scale Anywhere EP/V038087.