Dense pose estimation is a dense 3D prediction task for instance-level human analysis, aiming to map human pixels from an RGB image to a 3D surface of the human body. Due to a large amount of surface point regression, the training process appears to be easy to collapse compared to other region-based human instance analyzing tasks. By analyzing the loss formulation of the existing dense pose estimation model, we introduce a novel point regression loss function, named Dense Points} loss to stable the training progress, and a new balanced loss weighting strategy to handle the multi-task losses. With the above novelties, we propose a brand new architecture, named UV R-CNN. Without auxiliary supervision and external knowledge from other tasks, UV R-CNN can handle many complicated issues in dense pose model training progress, achieving 65.0% $AP_{gps}$ and 66.1% $AP_{gpsm}$ on the DensePose-COCO validation subset with ResNet-50-FPN feature extractor, competitive among the state-of-the-art dense human pose estimation methods.

人类茂密的估计旨在建立人体2D像素与3D人体模板之间的密集对应关系，是使机器能够了解图像中人员的关键技术。由于实际场景是复杂的，只有部分注释可用，导致无能为力或错误的估计，它仍然构成了几个挑战。在这项工作中，我们提出了一个新颖的框架，以检测图像中多人的密集。我们指的是知识转移网络（KTN）的建议方法解决了两个主要问题：1）如何完善图像表示以减轻不完整的估计，以及2）如何减少由低质量培训标签引起的错误估计（即。 ，有限的注释和班级不平衡标签）。与现有的作品直接传播区域的锥体特征以进行致密估计，KTN使用金字塔表示的改进，同时它可以维持特征分辨率并抑制背景像素，并且这种策略导致准确性大幅提高。此外，KTN通过外部知识增强了基于3D的身体解析的能力，在该知识中，它通过结构性的身体知识图，从足够的注释作为基于3D的身体解析器进行训练。通过这种方式，它大大减少了由低质量注释引起的不利影响。 KTN的有效性通过其优越的性能优于致密coco数据集的最先进方法。关于代表性任务（例如，人体分割，人体部分分割和关键点检测）和两个流行的致密估计管道（即RCNN和全面卷积框架）的广泛消融研究和实验结果，进一步表明了提议方法的概括性。

大多数最先进的实例级人类解析模型都采用了两阶段的基于锚的探测器，因此无法避免启发式锚盒设计和像素级别缺乏分析。为了解决这两个问题，我们设计了一个实例级人类解析网络，该网络在像素级别上无锚固且可解决。它由两个简单的子网络组成：一个用于边界框预测的无锚检测头和一个用于人体分割的边缘引导解析头。无锚探测器的头继承了像素样的优点，并有效地避免了对象检测应用中证明的超参数的敏感性。通过引入部分感知的边界线索，边缘引导的解析头能够将相邻的人类部分与彼此区分开，最多可在一个人类实例中，甚至重叠的实例。同时，利用了精炼的头部整合盒子级别的分数和部分分析质量，以提高解析结果的质量。在两个多个人类解析数据集（即CIHP和LV-MHP-V2.0）和一个视频实例级人类解析数据集（即VIP）上进行实验，表明我们的方法实现了超过全球级别和实例级别的性能最新的一阶段自上而下的替代方案。

Figure 1: Dense pose estimation aims at mapping all human pixels of an RGB image to the 3D surface of the human body. We introduce DensePose-COCO, a large-scale ground-truth dataset with image-to-surface correspondences manually annotated on 50K COCO images and train DensePose-RCNN, to densely regress part-specific UV coordinates within every human region at multiple frames per second. Left: The image and the regressed correspondence by DensePose-RCNN, Middle: DensePose COCO Dataset annotations, Right: Partitioning and UV parametrization of the body surface.

我们为变体视觉任务提供了一个概念上简单，灵活和通用的视觉感知头，例如分类，对象检测，实例分割和姿势估计以及不同的框架，例如单阶段或两个阶段的管道。我们的方法有效地标识了图像中的对象，同时同时生成高质量的边界框或基于轮廓的分割掩码或一组关键点。该方法称为Unihead，将不同的视觉感知任务视为通过变压器编码器体系结构学习的可分配点。给定固定的空间坐标，Unihead将其自适应地分散到了不同的空间点和有关它们的关系的原因。它以多个点的形式直接输出最终预测集，使我们能够在具有相同头部设计的不同框架中执行不同的视觉任务。我们展示了对成像网分类的广泛评估以及可可套件的所有三个曲目，包括对象检测，实例分割和姿势估计。如果没有铃铛和口哨声，Unihead可以通过单个视觉头设计统一这些视觉任务，并与为每个任务开发的专家模型相比，实现可比的性能。我们希望我们的简单和通用的Unihead能够成为可靠的基线，并有助于促进通用的视觉感知研究。代码和型号可在https://github.com/sense-x/unihead上找到。

Advances in computer vision and machine learning techniques have led to significant development in 2D and 3D human pose estimation from RGB cameras, LiDAR, and radars. However, human pose estimation from images is adversely affected by occlusion and lighting, which are common in many scenarios of interest. Radar and LiDAR technologies, on the other hand, need specialized hardware that is expensive and power-intensive. Furthermore, placing these sensors in non-public areas raises significant privacy concerns. To address these limitations, recent research has explored the use of WiFi antennas (1D sensors) for body segmentation and key-point body detection. This paper further expands on the use of the WiFi signal in combination with deep learning architectures, commonly used in computer vision, to estimate dense human pose correspondence. We developed a deep neural network that maps the phase and amplitude of WiFi signals to UV coordinates within 24 human regions. The results of the study reveal that our model can estimate the dense pose of multiple subjects, with comparable performance to image-based approaches, by utilizing WiFi signals as the only input. This paves the way for low-cost, broadly accessible, and privacy-preserving algorithms for human sensing.

We present a conceptually simple, flexible, and general framework for object instance segmentation. Our approach efficiently detects objects in an image while simultaneously generating a high-quality segmentation mask for each instance. The method, called Mask R-CNN, extends Faster R-CNN by adding a branch for predicting an object mask in parallel with the existing branch for bounding box recognition. Mask R-CNN is simple to train and adds only a small overhead to Faster R-CNN, running at 5 fps. Moreover, Mask R-CNN is easy to generalize to other tasks, e.g., allowing us to estimate human poses in the same framework. We show top results in all three tracks of the COCO suite of challenges, including instance segmentation, bounding-box object detection, and person keypoint detection. Without tricks, Mask R-CNN outperforms all existing, single-model entries on every task, including the COCO 2016 challenge winners. We hope our simple and effective approach will serve as a solid baseline and help ease future research in instance-level recognition. Code will be made available.

The topic of multi-person pose estimation has been largely improved recently, especially with the development of convolutional neural network. However, there still exist a lot of challenging cases, such as occluded keypoints, invisible keypoints and complex background, which cannot be well addressed. In this paper, we present a novel network structure called Cascaded Pyramid Network (CPN) which targets to relieve the problem from these "hard" keypoints. More specifically, our algorithm includes two stages: Glob-alNet and RefineNet. GlobalNet is a feature pyramid network which can successfully localize the "simple" keypoints like eyes and hands but may fail to precisely recognize the occluded or invisible keypoints. Our RefineNet tries explicitly handling the "hard" keypoints by integrating all levels of feature representations from the Global-Net together with an online hard keypoint mining loss. In general, to address the multi-person pose estimation problem, a top-down pipeline is adopted to first generate a set of human bounding boxes based on a detector, followed by our CPN for keypoint localization in each human bounding box. Based on the proposed algorithm, we achieve stateof-art results on the COCO keypoint benchmark, with average precision at 73.0 on the COCO test-dev dataset and 72.1 on the COCO test-challenge dataset, which is a 19% relative improvement compared with 60.5 from the COCO 2016 keypoint challenge. Code 1 and the detection results are publicly available for further research.

Accurate whole-body multi-person pose estimation and tracking is an important yet challenging topic in computer vision. To capture the subtle actions of humans for complex behavior analysis, whole-body pose estimation including the face, body, hand and foot is essential over conventional body-only pose estimation. In this paper, we present AlphaPose, a system that can perform accurate whole-body pose estimation and tracking jointly while running in realtime. To this end, we propose several new techniques: Symmetric Integral Keypoint Regression (SIKR) for fast and fine localization, Parametric Pose Non-Maximum-Suppression (P-NMS) for eliminating redundant human detections and Pose Aware Identity Embedding for jointly pose estimation and tracking. During training, we resort to Part-Guided Proposal Generator (PGPG) and multi-domain knowledge distillation to further improve the accuracy. Our method is able to localize whole-body keypoints accurately and tracks humans simultaneously given inaccurate bounding boxes and redundant detections. We show a significant improvement over current state-of-the-art methods in both speed and accuracy on COCO-wholebody, COCO, PoseTrack, and our proposed Halpe-FullBody pose estimation dataset. Our model, source codes and dataset are made publicly available at https://github.com/MVIG-SJTU/AlphaPose.

Due to object detection's close relationship with video analysis and image understanding, it has attracted much research attention in recent years. Traditional object detection methods are built on handcrafted features and shallow trainable architectures. Their performance easily stagnates by constructing complex ensembles which combine multiple low-level image features with high-level context from object detectors and scene classifiers. With the rapid development in deep learning, more powerful tools, which are able to learn semantic, high-level, deeper features, are introduced to address the problems existing in traditional architectures. These models behave differently in network architecture, training strategy and optimization function, etc. In this paper, we provide a review on deep learning based object detection frameworks. Our review begins with a brief introduction on the history of deep learning and its representative tool, namely Convolutional Neural Network (CNN). Then we focus on typical generic object detection architectures along with some modifications and useful tricks to improve detection performance further. As distinct specific detection tasks exhibit different characteristics, we also briefly survey several specific tasks, including salient object detection, face detection and pedestrian detection. Experimental analyses are also provided to compare various methods and draw some meaningful conclusions. Finally, several promising directions and tasks are provided to serve as guidelines for future work in both object detection and relevant neural network based learning systems.

现有的实例分割方法已经达到了令人印象深刻的表现，但仍遭受了共同的困境：一个实例推断出冗余表示（例如，多个框，网格和锚点），这导致了多个重复的预测。因此，主流方法通常依赖于手工设计的非最大抑制（NMS）后处理步骤来选择最佳预测结果，这会阻碍端到端训练。为了解决此问题，我们建议一个称为Uniinst的无盒和无端机实例分割框架，该框架仅对每个实例产生一个唯一的表示。具体而言，我们设计了一种实例意识到的一对一分配方案，即仅产生一个表示（Oyor），该方案根据预测和地面真相之间的匹配质量，动态地为每个实例动态分配一个独特的表示。然后，一种新颖的预测重新排列策略被优雅地集成到框架中，以解决分类评分和掩盖质量之间的错位，从而使学习的表示形式更具歧视性。借助这些技术，我们的Uniinst，第一个基于FCN的盒子和无NMS实例分段框架，实现竞争性能，例如，使用Resnet-50-FPN和40.2 mask AP使用Resnet-101-FPN，使用Resnet-50-FPN和40.2 mask AP，使用Resnet-101-FPN，对抗AP可可测试-DEV的主流方法。此外，提出的实例感知方法对于遮挡场景是可靠的，在重锁定的ochuman基准上，通过杰出的掩码AP优于公共基线。我们的代码将在出版后提供。

We propose a sparse end-to-end multi-person pose regression framework, termed QueryPose, which can directly predict multi-person keypoint sequences from the input image. The existing end-to-end methods rely on dense representations to preserve the spatial detail and structure for precise keypoint localization. However, the dense paradigm introduces complex and redundant post-processes during inference. In our framework, each human instance is encoded by several learnable spatial-aware part-level queries associated with an instance-level query. First, we propose the Spatial Part Embedding Generation Module (SPEGM) that considers the local spatial attention mechanism to generate several spatial-sensitive part embeddings, which contain spatial details and structural information for enhancing the part-level queries. Second, we introduce the Selective Iteration Module (SIM) to adaptively update the sparse part-level queries via the generated spatial-sensitive part embeddings stage-by-stage. Based on the two proposed modules, the part-level queries are able to fully encode the spatial details and structural information for precise keypoint regression. With the bipartite matching, QueryPose avoids the hand-designed post-processes and surpasses the existing dense end-to-end methods with 73.6 AP on MS COCO mini-val set and 72.7 AP on CrowdPose test set. Code is available at https://github.com/buptxyb666/QueryPose.

多次人类解析的现有方法通常采用两阶段的策略（通常是自下而上和自下而上），这遭受了对先前检测的强烈依赖，或者在集体后过程中高度计算的冗余。在这项工作中，我们使用代表性零件（称为Repparser）提出了一个端到端的多个人类解析框架。与主流方法不同，repparser以新的单阶段的方式解决了多个人的解析，而无需诉诸于人的检测或组后。为此，repparser将解析管道解析为实例感知的内核产生和部分意识到的人类解析，并将其分解为部分。分别负责实例分离和特定于实例的部分分割。特别是，我们通过代表性部分赋予解析管道的能力，因为它们的特征是通过实例感知关键点，并且可以用来动态解析每个人的实例。具体而言，代表性零件是通过共同定位实例中心和估计身体部位区域的关键来获得的。之后，我们通过代表性部分动态预测实例感知的卷积内核，从而将人零件的上下文编码为每个负责将图像特征施放为实例特定表示的内核。furthermore。采用多支出结构来分割每个实例 - 特定的表示单独的部分分割的几个部分感知表示。这样，以代表性零件的指导，重新集中在人实例上，并直接为每个人实例输出解析结果，从而消除了先前检测或发布的要求-grouping。在两个具有挑战性的基准上进行的扩展实验表明，我们提出的repparser是一个简单而有效的框架，并取得了竞争性的表现。

Body segmentation is an important step in many computer vision problems involving human images and one of the key components that affects the performance of all downstream tasks. Several prior works have approached this problem using a multi-task model that exploits correlations between different tasks to improve segmentation performance. Based on the success of such solutions, we present in this paper a novel multi-task model for human segmentation/parsing that involves three tasks, i.e., (i) keypoint-based skeleton estimation, (ii) dense pose prediction, and (iii) human-body segmentation. The main idea behind the proposed Segmentation--Pose--DensePose model (or SPD for short) is to learn a better segmentation model by sharing knowledge across different, yet related tasks. SPD is based on a shared deep neural network backbone that branches off into three task-specific model heads and is learned using a multi-task optimization objective. The performance of the model is analysed through rigorous experiments on the LIP and ATR datasets and in comparison to a recent (state-of-the-art) multi-task body-segmentation model. Comprehensive ablation studies are also presented. Our experimental results show that the proposed multi-task (segmentation) model is highly competitive and that the introduction of additional tasks contributes towards a higher overall segmentation performance.

In this paper, we introduce an anchor-box free and single shot instance segmentation method, which is conceptually simple, fully convolutional and can be used by easily embedding it into most off-the-shelf detection methods. Our method, termed PolarMask, formulates the instance segmentation problem as predicting contour of instance through instance center classification and dense distance regression in a polar coordinate. Moreover, we propose two effective approaches to deal with sampling high-quality center examples and optimization for dense distance regression, respectively, which can significantly improve the performance and simplify the training process. Without any bells and whistles, PolarMask achieves 32.9% in mask mAP with single-model and single-scale training/testing on the challenging COCO dataset.For the first time, we show that the complexity of instance segmentation, in terms of both design and computation complexity, can be the same as bounding box object detection and this much simpler and flexible instance segmentation framework can achieve competitive accuracy. We hope that the proposed PolarMask framework can serve as a fundamental and strong baseline for single shot instance segmentation task. Code is available at: github.com/xieenze/PolarMask.

分割高度重叠的图像对象是具有挑战性的，因为图像上的真实对象轮廓和遮挡边界之间通常没有区别。与先前的实例分割方法不同，我们将图像形成模拟为两个重叠层的组成，并提出了双层卷积网络（BCNET），其中顶层检测到遮挡对象（遮挡器），而底层则渗透到部分闭塞实例（胶囊）。遮挡关系与双层结构的显式建模自然地将遮挡和遮挡实例的边界解散，并在掩模回归过程中考虑了它们之间的相互作用。我们使用两种流行的卷积网络设计（即完全卷积网络（FCN）和图形卷积网络（GCN））研究了双层结构的功效。此外，我们通过将图像中的实例表示为单独的可学习封闭器和封闭者查询，从而使用视觉变压器（VIT）制定双层解耦。使用一个/两个阶段和基于查询的对象探测器具有各种骨架和网络层选择验证双层解耦合的概括能力，如图像实例分段基准（可可，亲戚，可可）和视频所示实例分割基准（YTVIS，OVIS，BDD100K MOTS），特别是对于重闭塞病例。代码和数据可在https://github.com/lkeab/bcnet上找到。

我们提出了一种用于多实例姿态估计的端到端培训方法，称为诗人（姿势估计变压器）。将卷积神经网络与变压器编码器 - 解码器架构组合，我们将多个姿势估计从图像标记为直接设置预测问题。我们的模型能够使用双方匹配方案直接出现所有个人的姿势。诗人使用基于集的全局损失进行培训，该丢失包括关键点损耗，可见性损失和载重损失。诗歌的原因与多个检测到的个人与完整图像上下文之间的关系直接预测它们并行姿势。我们展示诗人在Coco Keypoint检测任务上实现了高精度，同时具有比其他自下而上和自上而下的方法更少的参数和更高推理速度。此外，在将诗人应用于动物姿势估计时，我们表现出了成功的转移学习。据我们所知，该模型是第一个端到端的培训多实例姿态估计方法，我们希望它将成为一种简单而有前途的替代方案。

人搜索是多个子任务的集成任务，例如前景/背景分类，边界框回归和人员重新识别。因此，人搜索是一个典型的多任务学习问题，尤其是在以端到端方式解决时。最近，一些作品通过利用各种辅助信息，例如人关节关键点，身体部位位置，属性等，这带来了更多的任务并使人搜索模型更加复杂。每个任务的不一致的趋同率可能会损害模型优化。一个直接的解决方案是手动为不同的任务分配不同的权重，以补偿各种融合率。但是，鉴于人搜索的特殊情况，即有大量任务，手动加权任务是不切实际的。为此，我们提出了一种分组的自适应减肥方法（GALW）方法，该方法会自动和动态地调整每个任务的权重。具体而言，我们根据其收敛率对任务进行分组。同一组中的任务共享相同的可学习权重，这是通过考虑损失不确定性动态分配的。对两个典型基准（Cuhk-Sysu and Prw）的实验结果证明了我们方法的有效性。

Human parsing aims to partition humans in image or video into multiple pixel-level semantic parts. In the last decade, it has gained significantly increased interest in the computer vision community and has been utilized in a broad range of practical applications, from security monitoring, to social media, to visual special effects, just to name a few. Although deep learning-based human parsing solutions have made remarkable achievements, many important concepts, existing challenges, and potential research directions are still confusing. In this survey, we comprehensively review three core sub-tasks: single human parsing, multiple human parsing, and video human parsing, by introducing their respective task settings, background concepts, relevant problems and applications, representative literature, and datasets. We also present quantitative performance comparisons of the reviewed methods on benchmark datasets. Additionally, to promote sustainable development of the community, we put forward a transformer-based human parsing framework, providing a high-performance baseline for follow-up research through universal, concise, and extensible solutions. Finally, we point out a set of under-investigated open issues in this field and suggest new directions for future study. We also provide a regularly updated project page, to continuously track recent developments in this fast-advancing field: https://github.com/soeaver/awesome-human-parsing.

对象检测是典型的多任务学习应用程序，其同时优化分类和回归。但是，分类损失总是以基于锚的方法的多任务损失主导，妨碍了任务的一致和平衡优化。在本文中，我们发现转移边界盒可以在分类中改变正面和负样本的划分，意思是分类取决于回归。此外，考虑到不同的数据集，优化器和回归损耗功能，我们总结了关于微调损耗重量的三个重要结论。基于上述结论，我们提出了自适应损失重量调整（ALWA）以根据损失的统计特征来解决优化基于锚的方法的不平衡。通过将Alwa纳入以前的最先进的探测器，我们在Pascal VOC和MS Coco上实现了显着的性能增益，即使是L1，Smoothl1和Ciou丢失。代码可在https://github.com/ywx-hub/alwa获得。