arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1805.04092cs.CV
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学习从单色图像估计3D人体姿态和形状

Learning to Estimate 3D Human Pose and Shape from a Single Color Image

University of Pennsylvania(宾夕法尼亚大学);Peking University(北京大学);Zhejiang University(浙江大学)

Georgios Pavlakos, Luyang Zhu, Xiaowei Zhou, Kostas Daniilidis

摘要:

这项工作解决的问题,估计全身三维人体姿势和形状从一个单一的彩色图像。这是一项基于迭代优化的解决方案通常占上风的任务,而卷积网络(ConvNets)由于缺乏训练数据及其低分辨率3D预测而受到影响。我们的工作旨在弥合这一差距,并提出了一种基于ConvNets的高效和有效的直接预测方法。我们的方法的核心部分是在我们的端到端框架内纳入参数统计体型模型(SMPL)。这使我们能够获得非常详细的3D网格结果,同时只需要估计少量参数,使其对直接网络预测非常友好。有趣的是,我们证明了这些参数只能从2D关键点和掩码中可靠地预测。这些是通用2D人体分析ConvNets的典型输出,使我们能够放松对具有3D形状地面真实值的图像可用于训练的大量要求。同时,通过保持可微性,在训练时,我们从估计的参数生成3D网格,并使用3D逐顶点损失显式优化表面。最后,采用可微分渲染器将3D网格投影到图像,这通过优化投影与2D注释的一致性(即,2D关键点或遮罩)。所提出的方法在这项任务上优于以前的基线,并提供了一个有吸引力的解决方案,从一个单一的彩色图像的3D形状的直接预测。

英文摘要:

This work addresses the problem of estimating the full body 3D human pose and shape from a single color image. This is a task where iterative optimization-based solutions have typically prevailed, while Convolutional Networks (ConvNets) have suffered because of the lack of training data and their low resolution 3D predictions. Our work aims to bridge this gap and proposes an efficient and effective direct prediction method based on ConvNets. Central part to our approach is the incorporation of a parametric statistical body shape model (SMPL) within our end-to-end framework. This allows us to get very detailed 3D mesh results, while requiring estimation only of a small number of parameters, making it friendly for direct network prediction. Interestingly, we demonstrate that these parameters can be predicted reliably only from 2D keypoints and masks. These are typical outputs of generic 2D human analysis ConvNets, allowing us to relax the massive requirement that images with 3D shape ground truth are available for training. Simultaneously, by maintaining differentiability, at training time we generate the 3D mesh from the estimated parameters and optimize explicitly for the surface using a 3D per-vertex loss. Finally, a differentiable renderer is employed to project the 3D mesh to the image, which enables further refinement of the network, by optimizing for the consistency of the projection with 2D annotations (i.e., 2D keypoints or masks). The proposed approach outperforms previous baselines on this task and offers an attractive solution for direct prediction of 3D shape from a single color image.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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