Traditionally, monocular 3D human pose estimation employs a machine learning model to predict the most likely 3D pose for a given input image. However, a single image can be highly ambiguous and induces multiple plausible solutions for the 2D-3D lifting step which results in overly confident 3D pose predictors. To this end, we propose \emph{DiffPose}, a conditional diffusion model, that predicts multiple hypotheses for a given input image. In comparison to similar approaches, our diffusion model is straightforward and avoids intensive hyperparameter tuning, complex network structures, mode collapse, and unstable training. Moreover, we tackle a problem of the common two-step approach that first estimates a distribution of 2D joint locations via joint-wise heatmaps and consecutively approximates them based on first- or second-moment statistics. Since such a simplification of the heatmaps removes valid information about possibly correct, though labeled unlikely, joint locations, we propose to represent the heatmaps as a set of 2D joint candidate samples. To extract information about the original distribution from these samples we introduce our \emph{embedding transformer} that conditions the diffusion model. Experimentally, we show that DiffPose slightly improves upon the state of the art for multi-hypothesis pose estimation for simple poses and outperforms it by a large margin for highly ambiguous poses.

Thanks to the development of 2D keypoint detectors, monocular 3D human pose estimation (HPE) via 2D-to-3D uplifting approaches have achieved remarkable improvements. Still, monocular 3D HPE is a challenging problem due to the inherent depth ambiguities and occlusions. To handle this problem, many previous works exploit temporal information to mitigate such difficulties. However, there are many real-world applications where frame sequences are not accessible. This paper focuses on reconstructing a 3D pose from a single 2D keypoint detection. Rather than exploiting temporal information, we alleviate the depth ambiguity by generating multiple 3D pose candidates which can be mapped to an identical 2D keypoint. We build a novel diffusion-based framework to effectively sample diverse 3D poses from an off-the-shelf 2D detector. By considering the correlation between human joints by replacing the conventional denoising U-Net with graph convolutional network, our approach accomplishes further performance improvements. We evaluate our method on the widely adopted Human3.6M and HumanEva-I datasets. Comprehensive experiments are conducted to prove the efficacy of the proposed method, and they confirm that our model outperforms state-of-the-art multi-hypothesis 3D HPE methods.

Monocular 3D human pose estimation is quite challenging due to the inherent ambiguity and occlusion, which often lead to high uncertainty and indeterminacy. On the other hand, diffusion models have recently emerged as an effective tool for generating high-quality images from noise. Inspired by their capability, we explore a novel pose estimation framework (DiffPose) that formulates 3D pose estimation as a reverse diffusion process. We incorporate novel designs into our DiffPose that facilitate the diffusion process for 3D pose estimation: a pose-specific initialization of pose uncertainty distributions, a Gaussian Mixture Model-based forward diffusion process, and a context-conditioned reverse diffusion process. Our proposed DiffPose significantly outperforms existing methods on the widely used pose estimation benchmarks Human3.6M and MPI-INF-3DHP.

从单个图像的人类姿势估计是一个充满挑战的问题，通常通过监督学习解决。不幸的是，由于3D注释需要专用的运动捕获系统，因此许多人类活动尚不存在标记的培训数据。因此，我们提出了一种无监督的方法，该方法学会从单个图像预测3D人类姿势，同时只有2D姿势数据培训，这可能是人群的并且已经广泛可用。为此，我们估计最有可能过于随机投影的3D姿势，其中使用2D姿势的归一化流程估计的可能性。虽然以前的工作需要在训练数据集中的相机旋转上需要强大的前锋，但我们了解了相机角度的分布，显着提高了性能。我们的贡献的另一部分是通过首先将2D突出到线性子空间来稳定高维3D姿势数据上的标准化流动的训练。在许多指标中，我们优于基准数据集Humanets3.6m和MPI-INF-3DHP的最先进的无人监督的人类姿势估算方法。

Learning 3D human pose prior is essential to human-centered AI. Here, we present GFPose, a versatile framework to model plausible 3D human poses for various applications. At the core of GFPose is a time-dependent score network, which estimates the gradient on each body joint and progressively denoises the perturbed 3D human pose to match a given task specification. During the denoising process, GFPose implicitly incorporates pose priors in gradients and unifies various discriminative and generative tasks in an elegant framework. Despite the simplicity, GFPose demonstrates great potential in several downstream tasks. Our experiments empirically show that 1) as a multi-hypothesis pose estimator, GFPose outperforms existing SOTAs by 20% on Human3.6M dataset. 2) as a single-hypothesis pose estimator, GFPose achieves comparable results to deterministic SOTAs, even with a vanilla backbone. 3) GFPose is able to produce diverse and realistic samples in pose denoising, completion and generation tasks. Project page https://sites.google.com/view/gfpose/

Stochastic human motion prediction aims to forecast multiple plausible future motions given a single pose sequence from the past. Most previous works focus on designing elaborate losses to improve the accuracy, while the diversity is typically characterized by randomly sampling a set of latent variables from the latent prior, which is then decoded into possible motions. This joint training of sampling and decoding, however, suffers from posterior collapse as the learned latent variables tend to be ignored by a strong decoder, leading to limited diversity. Alternatively, inspired by the diffusion process in nonequilibrium thermodynamics, we propose MotionDiff, a diffusion probabilistic model to treat the kinematics of human joints as heated particles, which will diffuse from original states to a noise distribution. This process offers a natural way to obtain the "whitened" latents without any trainable parameters, and human motion prediction can be regarded as the reverse diffusion process that converts the noise distribution into realistic future motions conditioned on the observed sequence. Specifically, MotionDiff consists of two parts: a spatial-temporal transformer-based diffusion network to generate diverse yet plausible motions, and a graph convolutional network to further refine the outputs. Experimental results on two datasets demonstrate that our model yields the competitive performance in terms of both accuracy and diversity.

大多数实时人类姿势估计方法都基于检测接头位置。使用检测到的关节位置，可以计算偏差和肢体的俯仰。然而，由于这种旋转轴仍然不观察，因此不能计算沿着肢体沿着肢体至关重要的曲折，这对于诸如体育分析和计算机动画至关重要。在本文中，我们引入了方向关键点，一种用于估计骨骼关节的全位置和旋转的新方法，仅使用单帧RGB图像。灵感来自Motion-Capture Systems如何使用一组点标记来估计全骨骼旋转，我们的方法使用虚拟标记来生成足够的信息，以便准确地推断使用简单的后处理。旋转预测改善了接头角度最佳报告的平均误差48％，并且在15个骨骼旋转中实现了93％的精度。该方法还通过MPJPE在原理数据集上测量，通过MPJPE测量，该方法还改善了当前的最新结果14％，并概括为野外数据集。

估计单眼视频的3D人类姿势是由于深度模糊和自动阻塞的具有挑战性的任务。大多数现有的作品试图通过利用空间和时间关系来解决这两个问题。然而，这些作品忽略了它是存在多种可行解决方案（即假设）的逆问题。为了减轻这种限制，我们提出了一种多假设变压器（MHFormer），其学习多个合理的姿势假设的时空表示。为了有效地模拟多假设依赖性并构建跨假设特征的强烈关系，任务分解为三个阶段：（i）生成多个初始假设表示; （ii）模型自立通信，将多个假设合并到单个融合表示中，然后将其分组成几个分歧假设; （iii）学习横向假设通信并汇总多假设特征以合成最终的3D姿势。通过上述过程，最终表示增强，合成的姿势更准确。广泛的实验表明，MHFORMER在两个具有挑战性的数据集上实现最先进的结果：Humanet3.6M和MPI-INF-3DHP。没有钟声和吹口哨，其性能超过了以人3.6M的大幅度为3％的最佳结果。代码和模型可在https://github.com/vegetebird/mhformer中找到。

Figure 1: Given challenging in-the-wild videos, a recent state-of-the-art video-pose-estimation approach [31] (top), fails to produce accurate 3D body poses. To address this, we exploit a large-scale motion-capture dataset to train a motion discriminator using an adversarial approach. Our model (VIBE) (bottom) is able to produce realistic and accurate pose and shape, outperforming previous work on standard benchmarks.

Estimating 3D human motion from an egocentric video sequence is critical to human behavior understanding and applications in VR/AR. However, naively learning a mapping between egocentric videos and human motions is challenging, because the user's body is often unobserved by the front-facing camera placed on the head of the user. In addition, collecting large-scale, high-quality datasets with paired egocentric videos and 3D human motions requires accurate motion capture devices, which often limit the variety of scenes in the videos to lab-like environments. To eliminate the need for paired egocentric video and human motions, we propose a new method, Ego-Body Pose Estimation via Ego-Head Pose Estimation (EgoEgo), that decomposes the problem into two stages, connected by the head motion as an intermediate representation. EgoEgo first integrates SLAM and a learning approach to estimate accurate head motion. Then, taking the estimated head pose as input, it leverages conditional diffusion to generate multiple plausible full-body motions. This disentanglement of head and body pose eliminates the need for training datasets with paired egocentric videos and 3D human motion, enabling us to leverage large-scale egocentric video datasets and motion capture datasets separately. Moreover, for systematic benchmarking, we develop a synthetic dataset, AMASS-Replica-Ego-Syn (ARES), with paired egocentric videos and human motion. On both ARES and real data, our EgoEgo model performs significantly better than the state-of-the-art.

We propose a CNN-based approach for 3D human body pose estimation from single RGB images that addresses the issue of limited generalizability of models trained solely on the starkly limited publicly available 3D pose data. Using only the existing 3D pose data and 2D pose data, we show state-of-the-art performance on established benchmarks through transfer of learned features, while also generalizing to in-the-wild scenes. We further introduce a new training set for human body pose estimation from monocular images of real humans that has the ground truth captured with a multi-camera marker-less motion capture system. It complements existing corpora with greater diversity in pose, human appearance, clothing, occlusion, and viewpoints, and enables an increased scope of augmentation. We also contribute a new benchmark that covers outdoor and indoor scenes, and demonstrate that our 3D pose dataset shows better in-the-wild performance than existing annotated data, which is further improved in conjunction with transfer learning from 2D pose data. All in all, we argue that the use of transfer learning of representations in tandem with algorithmic and data contributions is crucial for general 3D body pose estimation.

培训视频中人类姿势估计的最先进模型需要具有很难获得的注释的数据集。尽管最近已将变压器用于身体姿势序列建模，但相关方法依靠伪地真相来增强目前有限的培训数据可用于学习此类模型。在本文中，我们介绍了Posebert，Posebert是一个通过掩盖建模对3D运动捕获（MOCAP）数据进行全面训练的变压器模块。它是简单，通用和通用的，因为它可以插入任何基于图像的模型的顶部，以在基于视频的模型中使用时间信息。我们展示了Posebert的变体，不同的输入从3D骨骼关键点到全身或仅仅是手（Mano）的3D参数模型的旋转。由于Posebert培训是任务不可知论的，因此该模型可以应用于姿势细化，未来的姿势预测或运动完成等几个任务。我们的实验结果验证了在各种最新姿势估计方法之上添加Posebert始终提高其性能，而其低计算成本使我们能够在实时演示中使用它，以通过A的机器人手使机器人手通过摄像头。可以在https://github.com/naver/posebert上获得测试代码和型号。

在计算机视觉中起关键作用的人类运动预测通常需要过去的运动序列作为输入。但是，在实际应用中，完整而正确的过去运动顺序可能太贵了。在本文中，我们提出了一种新的方法，可以从更弱的条件（即单个图像）中预测未来的人类运动，并具有混合密度网络（MDN）建模。与大多数现有的深层人类运动预测方法相反，MDN的多模式性质可以产生各种未来的运动假设，这很好地补偿了由单个输入和人类运动不确定性汇总的强烈随机歧义。在设计损失函数时，我们进一步引入了基于能量的公式，以灵活地对MDN的可学习参数施加先前的损失，以保持运动相干性，并通过自定义能量功能来提高预测准确性。我们训练有素的模型将图像直接作为输入，并生成满足给定条件的多个合理动作。在两个标准基准数据集上进行的广泛实验证明了我们方法在预测多样性和准确性方面的有效性。

Following the success of deep convolutional networks, state-of-the-art methods for 3d human pose estimation have focused on deep end-to-end systems that predict 3d joint locations given raw image pixels. Despite their excellent performance, it is often not easy to understand whether their remaining error stems from a limited 2d pose (visual) understanding, or from a failure to map 2d poses into 3dimensional positions.With the goal of understanding these sources of error, we set out to build a system that given 2d joint locations predicts 3d positions. Much to our surprise, we have found that, with current technology, "lifting" ground truth 2d joint locations to 3d space is a task that can be solved with a remarkably low error rate: a relatively simple deep feedforward network outperforms the best reported result by about 30% on Human3.6M, the largest publicly available 3d pose estimation benchmark. Furthermore, training our system on the output of an off-the-shelf state-of-the-art 2d detector (i.e., using images as input) yields state of the art results -this includes an array of systems that have been trained end-to-end specifically for this task. Our results indicate that a large portion of the error of modern deep 3d pose estimation systems stems from their visual analysis, and suggests directions to further advance the state of the art in 3d human pose estimation.

In recent years, generative models have undergone significant advancement due to the success of diffusion models. The success of these models is often attributed to their use of guidance techniques, such as classifier and classifier-free methods, which provides effective mechanisms to trade-off between fidelity and diversity. However, these methods are not capable of guiding a generated image to be aware of its geometric configuration, e.g., depth, which hinders the application of diffusion models to areas that require a certain level of depth awareness. To address this limitation, we propose a novel guidance approach for diffusion models that uses estimated depth information derived from the rich intermediate representations of diffusion models. To do this, we first present a label-efficient depth estimation framework using the internal representations of diffusion models. At the sampling phase, we utilize two guidance techniques to self-condition the generated image using the estimated depth map, the first of which uses pseudo-labeling, and the subsequent one uses a depth-domain diffusion prior. Experiments and extensive ablation studies demonstrate the effectiveness of our method in guiding the diffusion models toward geometrically plausible image generation. Project page is available at https://ku-cvlab.github.io/DAG/.

传统的3D人姿态估计依赖于首次检测2D身体键盘，然后求解2D到3D对应问题。提高有希望的结果，该学习范例高度依赖于2D关键点检测器的质量，这不可避免地易于闭塞和堵塞-of-image缺席。在本文中，我们提出了一种新颖的姿势定向网（PONET），其能够仅通过学习方向估计3D姿势，因此在没有图像证据的情况下绕过错误易于keypoint检测器。对于具有部分不可见的四肢的图像，Ponet通过利用本地图像证据来恢复3D姿势来估计这些肢体的3D方向。通过利用完全看不见的四肢来说，Ponet甚至可以从完全看不见的四肢的图像中推断出完整的3D姿势。可见肢体之间的取向相关性以补充估计的姿势，进一步提高了3D姿态估计的鲁棒性。我们在多个数据集中评估我们的方法，包括Human3.6M，MPII，MPI-INF-3DHP和3DPW。我们的方法在理想设置中实现了与最先进的技术的结果，但显着消除了对关键点检测器和相应的计算负担的依赖性。在截断和擦除等方面的高度挑战性方案中，我们的方法稳健地表现得非常强大，与本领域的状态相比，展示其对现实世界应用的可能性。

我们考虑从野外拥挤的场景中恢复一个人的3D人网格的问题。尽管在3D人网估计中取得了很多进展，但当测试输入的场景拥挤时，现有的方法很难。失败的第一个原因是训练和测试数据之间的域间隙。一个运动捕获数据集为训练提供准确的3D标签，缺乏人群数据，并阻碍了网络无法学习目标人的拥挤场景射击图像特征。第二个原因是功能处理，该功能处理在空间上平均包含多个人的本地化边界框的特征图。平均整个功能映射使目标人的特征与他人无法区分。我们提出了3dcrowdnet，首先要明确针对野生野外的场景，并通过解决上述问题来估算强大的3D人网。首先，我们利用2D人姿势估计不需要带有3D标签的运动捕获数据集进行训练，并且不受域间隙的困扰。其次，我们提出了一个基于联合的回归器，将目标人的特征与他人区分开来。我们的基于联合的回归器通过对目标关节位置的采样特征来保留目标的空间激活并回归人类模型参数。结果，3DCORDNET学习了针对目标的功能，并有效地排除了附近人的无关特征。我们对各种基准进行实验，并证明3dcrowdnet对野外拥挤的场景的鲁棒性在定量和定性上。该代码可在https://github.com/hongsukchoi/3dcrowdnet_release上获得。

Conventional methods for human motion synthesis are either deterministic or struggle with the trade-off between motion diversity and motion quality. In response to these limitations, we introduce MoFusion, i.e., a new denoising-diffusion-based framework for high-quality conditional human motion synthesis that can generate long, temporally plausible, and semantically accurate motions based on a range of conditioning contexts (such as music and text). We also present ways to introduce well-known kinematic losses for motion plausibility within the motion diffusion framework through our scheduled weighting strategy. The learned latent space can be used for several interactive motion editing applications -- like inbetweening, seed conditioning, and text-based editing -- thus, providing crucial abilities for virtual character animation and robotics. Through comprehensive quantitative evaluations and a perceptual user study, we demonstrate the effectiveness of MoFusion compared to the state of the art on established benchmarks in the literature. We urge the reader to watch our supplementary video and visit https://vcai.mpi-inf.mpg.de/projects/MoFusion.

本文认为共同解决估计3D人体的高度相关任务，并从RGB图像序列预测未来的3D运动。基于Lie代数姿势表示，提出了一种新的自投影机制，自然保留了人类运动运动学。通过基于编码器 - 解码器拓扑的序列到序列的多任务架构进一步促进了这一点，这使我们能够利用两个任务共享的公共场所。最后，提出了一个全球细化模块来提高框架的性能。我们的方法称为PoMomemet的效力是通过消融测试和人文3.6M和Humaneva-I基准的实证评估，从而获得与最先进的竞争性能。

人类姿势和形状估计的任务中的关键挑战是闭塞，包括自闭合，对象 - 人闭塞和人际闭塞。缺乏多样化和准确的姿势和形状训练数据成为一个主要的瓶颈，特别是对于野外闭塞的场景。在本文中，我们专注于在人际闭塞的情况下估计人类姿势和形状，同时处理对象 - 人闭塞和自动闭塞。我们提出了一种新颖的框架，该框架综合了遮挡感知的轮廓和2D关键点数据，并直接回归到SMPL姿势和形状参数。利用神经3D网格渲染器以启用剪影监控，这有助于形状估计的巨大改进。此外，合成了全景视点中的关键点和轮廓驱动的训练数据，以补偿任何现有数据集中缺乏视点的多样性。实验结果表明，在姿势估计准确性方面，我们在3DPW和3DPW-Crowd数据集中是最先进的。所提出的方法在形状估计方面显着优于秩1方法。在形状预测精度方面，SSP-3D还实现了顶级性能。