Person re-identification is a challenging task because of the high intra-class variance induced by the unrestricted nuisance factors of variations such as pose, illumination, viewpoint, background, and sensor noise. Recent approaches postulate that powerful architectures have the capacity to learn feature representations invariant to nuisance factors, by training them with losses that minimize intra-class variance and maximize inter-class separation, without modeling nuisance factors explicitly. The dominant approaches use either a discriminative loss with margin, like the softmax loss with the additive angular margin, or a metric learning loss, like the triplet loss with batch hard mining of triplets. Since the softmax imposes feature normalization, it limits the gradient flow supervising the feature embedding. We address this by joining the losses and leveraging the triplet loss as a proxy for the missing gradients. We further improve invariance to nuisance factors by adding the discriminative task of predicting attributes. Our extensive evaluation highlights that when only a holistic representation is learned, we consistently outperform the state-of-the-art on the three most challenging datasets. Such representations are easier to deploy in practical systems. Finally, we found that joining the losses removes the requirement for having a margin in the softmax loss while increasing performance.

Recently, a popular line of research in face recognition is adopting margins in the well-established softmax loss function to maximize class separability. In this paper, we first introduce an Additive Angular Margin Loss (ArcFace), which not only has a clear geometric interpretation but also significantly enhances the discriminative power. Since ArcFace is susceptible to the massive label noise, we further propose sub-center ArcFace, in which each class contains K sub-centers and training samples only need to be close to any of the K positive sub-centers. Sub-center ArcFace encourages one dominant sub-class that contains the majority of clean faces and non-dominant sub-classes that include hard or noisy faces. Based on this self-propelled isolation, we boost the performance through automatically purifying raw web faces under massive real-world noise. Besides discriminative feature embedding, we also explore the inverse problem, mapping feature vectors to face images. Without training any additional generator or discriminator, the pre-trained ArcFace model can generate identity-preserved face images for both subjects inside and outside the training data only by using the network gradient and Batch Normalization (BN) priors. Extensive experiments demonstrate that ArcFace can enhance the discriminative feature embedding as well as strengthen the generative face synthesis.

人重新识别是识别非重叠摄像机的个体的问题。尽管在重新识别问题中取得了显着进展，但由于同一人的外观变化以及其他外观相似的人，这仍然是一个具有挑战性的问题。一些先前的作品通过将正样本的特征与负面的特征分开来解决这些问题。但是，现有模型的性能在很大程度上取决于用于培训的样品的特征和统计数据。因此，我们提出了一个名为“采样独立鲁棒特征表示网络”（sirnet）的新型框架，该框架学习了从随机选择的样品中嵌入的分离特征。对精心设计的采样独立的最大差异损失引入了与集群同一人的模型样本。结果，所提出的框架可以使用学识渊博的功能产生额外的硬质量/积极因素，从而可以更好地辨别其他身份。大规模基准数据集的广泛实验结果验证了所提出的模型比以前的最新模型更有效。

Person re-identification (Re-ID) aims at retrieving a person of interest across multiple non-overlapping cameras. With the advancement of deep neural networks and increasing demand of intelligent video surveillance, it has gained significantly increased interest in the computer vision community. By dissecting the involved components in developing a person Re-ID system, we categorize it into the closed-world and open-world settings. The widely studied closed-world setting is usually applied under various research-oriented assumptions, and has achieved inspiring success using deep learning techniques on a number of datasets. We first conduct a comprehensive overview with in-depth analysis for closed-world person Re-ID from three different perspectives, including deep feature representation learning, deep metric learning and ranking optimization. With the performance saturation under closed-world setting, the research focus for person Re-ID has recently shifted to the open-world setting, facing more challenging issues. This setting is closer to practical applications under specific scenarios. We summarize the open-world Re-ID in terms of five different aspects. By analyzing the advantages of existing methods, we design a powerful AGW baseline, achieving state-of-the-art or at least comparable performance on twelve datasets for FOUR different Re-ID tasks. Meanwhile, we introduce a new evaluation metric (mINP) for person Re-ID, indicating the cost for finding all the correct matches, which provides an additional criteria to evaluate the Re-ID system for real applications. Finally, some important yet under-investigated open issues are discussed.

Person recognition at a distance entails recognizing the identity of an individual appearing in images or videos collected by long-range imaging systems such as drones or surveillance cameras. Despite recent advances in deep convolutional neural networks (DCNNs), this remains challenging. Images or videos collected by long-range cameras often suffer from atmospheric turbulence, blur, low-resolution, unconstrained poses, and poor illumination. In this paper, we provide a brief survey of recent advances in person recognition at a distance. In particular, we review recent work in multi-spectral face verification, person re-identification, and gait-based analysis techniques. Furthermore, we discuss the merits and drawbacks of existing approaches and identify important, yet under explored challenges for deploying remote person recognition systems in-the-wild.

学习模态不变功能是可见热跨模板人员重新凝视（VT-REID）问题的核心，其中查询和画廊图像来自不同的模式。现有工作通过使用对抗性学习或仔细设计特征提取模块来隐式地将像素和特征空间中的模态对齐。我们提出了一个简单但有效的框架MMD-REID，通过明确的差异减少约束来降低模态差距。 MMD-REID从最大均值（MMD）中获取灵感，广泛使用的统计工具用于确定两个分布之间的距离。 MMD-REID采用新的基于边缘的配方，以匹配可见和热样品的类条件特征分布，以最大限度地减少级别的距离，同时保持特征辨别性。 MMD-Reid是一个简单的架构和损失制定方面的框架。我们对MMD-REID的有效性进行了广泛的实验，以使MMD-REID对调整边缘和阶级条件分布的有效性，从而学习模型无关和身份的一致特征。所提出的框架显着优于Sysu-MM01和RegDB数据集的最先进的方法。代码将在https://github.com/vcl-iisc/mmd -reid发布

This paper addresses deep face recognition (FR) problem under open-set protocol, where ideal face features are expected to have smaller maximal intra-class distance than minimal inter-class distance under a suitably chosen metric space. However, few existing algorithms can effectively achieve this criterion. To this end, we propose the angular softmax (A-Softmax) loss that enables convolutional neural networks (CNNs) to learn angularly discriminative features. Geometrically, A-Softmax loss can be viewed as imposing discriminative constraints on a hypersphere manifold, which intrinsically matches the prior that faces also lie on a manifold. Moreover, the size of angular margin can be quantitatively adjusted by a parameter m. We further derive specific m to approximate the ideal feature criterion. Extensive analysis and experiments on Labeled Face in the Wild (LFW), Youtube Faces (YTF) and MegaFace Challenge show the superiority of A-Softmax loss in FR tasks. The code has also been made publicly available 1 .

The combination of global and partial features has been an essential solution to improve discriminative performances in person re-identification (Re-ID) tasks. Previous part-based methods mainly focus on locating regions with specific pre-defined semantics to learn local representations, which increases learning difficulty but not efficient or robust to scenarios with large variances. In this paper, we propose an end-to-end feature learning strategy integrating discriminative information with various granularities. We carefully design the Multiple Granularity Network (MGN), a multi-branch deep network architecture consisting of one branch for global feature representations and two branches for local feature representations. Instead of learning on semantic regions, we uniformly partition the images into several stripes, and vary the number of parts in different local branches to obtain local feature representations with multiple granularities. Comprehensive experiments implemented on the mainstream evaluation datasets including Market-1501, DukeMTMC-reid and CUHK03 indicate that our method robustly achieves state-of-the-art performances and outperforms any existing approaches by a large margin. For example, on Market-1501 dataset in single query mode, we obtain a top result of Rank-1/mAP=96.6%/94.2% with this method after re-ranking.

从图像中学习代表，健壮和歧视性信息对于有效的人重新识别（RE-ID）至关重要。在本文中，我们提出了一种基于身体和手部图像的人重新ID的端到端判别深度学习的复合方法。我们仔细设计了本地感知的全球注意力网络（Laga-Net），这是一个多分支深度网络架构，由一个用于空间注意力的分支组成，一个用于渠道注意。注意分支集中在图像的相关特征上，同时抑制了无关紧要的背景。为了克服注意力机制的弱点，与像素改组一样，我们将相对位置编码整合到空间注意模块中以捕获像素的空间位置。全球分支机构打算保留全球环境或结构信息。对于打算捕获细粒度信息的本地分支，我们进行统一的分区以水平在Conv-Layer上生成条纹。我们通过执行软分区来检索零件，而无需明确分区图像或需要外部线索，例如姿势估计。一组消融研究表明，每个组件都会有助于提高拉加网络的性能。对四个受欢迎的人体重新ID基准和两个公开可用的手数据集的广泛评估表明，我们的建议方法始终优于现有的最新方法。

由于其在智能城市和城市监测中的潜在应用，车辆重新ID最近引起了热烈的关注。然而，它遭受了通过观察变化和照明变化引起的大型阶级变化，以及阶级相似性，特别是对于具有类似外观的不同标识。为了处理这些问题，在本文中，我们提出了一种新颖的深度网络架构，其由有意义的属性引导，包括相机视图，车辆类型和用于车辆RE-ID的颜色。特别是，我们的网络是端到端训练的，并包含由相应属性嵌入的深度特征的三个子网（即，相机视图，车辆类型和车辆颜色）。此外，为了克服不同视图的有限载体图像的缺点，我们设计了一个视图指定的生成的对抗性网络来生成多视图车辆图像。对于网络培训，我们在Veri-776数据集上注释了视图标签。请注意，只能使用ID信息直接在其他数据集上直接在其他数据集上采用预先训练的视图（以及类型和颜色）子网，这展示了我们模型的泛化。基准数据集Veri-776和车辆的广泛实验表明，拟议的方法实现了有希望的性能，并对车辆重新ID的新型最先进的性能。

近年来，随着对公共安全的需求越来越多，智能监测网络的快速发展，人员重新识别（RE-ID）已成为计算机视野领域的热门研究主题之一。人员RE-ID的主要研究目标是从不同的摄像机中检索具有相同身份的人。但是，传统的人重新ID方法需要手动标记人的目标，这消耗了大量的劳动力成本。随着深度神经网络的广泛应用，出现了许多基于深入的基于学习的人物的方法。因此，本文促进研究人员了解最新的研究成果和该领域的未来趋势。首先，我们总结了对几个最近公布的人的研究重新ID调查，并补充了系统地分类基于深度学习的人的重新ID方法的最新研究方法。其次，我们提出了一种多维分类，根据度量标准和表示学习，将基于深度学习的人的重新ID方法分为四类，包括深度度量学习，本地特征学习，生成的对抗学习和序列特征学习的方法。此外，我们根据其方法和动机来细分以上四类，讨论部分子类别的优缺点。最后，我们讨论了一些挑战和可能的研究方向的人重新ID。

近年来，人们对建立面孔和名人声音之间的关联的兴趣越来越大，从而利用YouTube的视听信息。先前的工作采用公制学习方法来学习适合关联匹配和验证任务的嵌入式空间。尽管显示出一些进展，但由于依赖距离依赖的边缘参数，运行时训练的复杂性差以及对精心制作的负面采矿程序的依赖，这种制剂是限制性的。在这项工作中，我们假设一个丰富的表示形式以及有效但有效的监督对于实现面部voice关联任务的歧视性关节嵌入空间很重要。为此，我们提出了一种轻巧的插件机制，该机制利用这两种方式中的互补线索以通过正交性约束来根据其身份标签形成丰富的融合杂物并将其簇形成。我们将我们提出的机制作为融合和正交投影（FOP）创造，并在两个流网络中实例化。在Voxceleb1和Mav-Celeb数据集上评估了总体结果框架，其中包括许多任务，包括跨模式验证和匹配。结果表明，我们的方法对当前的最新方法有利，而我们提出的监督表述比当代方法所采用的方法更有效。此外，我们还利用跨模式验证和匹配任务来分析多种语言对面部声音协会的影响。代码可用：\ url {https://github.com/msaadsaeed/fop}

人类识别是事件检测，人跟踪和公共安全的重要课题。有许多方法提出了人类识别，例如面部识别，人重新识别和步态识别。通常，现有方法主要将查询图像分类为图像库集合（I2i）中的特定标识。这对场景非常有限，其中仅在广泛的视频监控应用程序（A2i或I2a）中提供了查询或属性库集合的文本描述。然而，非常少量的努力已经致力于无模式识别，即，以可扩展的方式识别在库中设置的查询。在这项工作中，我们采取初步尝试，并以可扩展的方式制定这样一种新的无模式人类识别（命名为MFHI）任务作为通用零射击学习模型。同时，它能够通过学习每个身份的鉴别性原型来弥合视觉和语义模态。此外，在视觉模型上强制执行语义引导的空间注意，以获得具有高全局类别级和本地属性级别辨别的表示。最后，我们在两个共同挑战的识别任务中设计和开展广泛的实验，包括面部识别和人员重新识别，证明我们的方法优于一种在无模式人体识别方面的各种最先进的方法。

最近的研究表明，明确的深度特征匹配以及大规模和多样化的训练数据都可以显着提高人员重新识别的泛化。然而，在大规模数据上学习深度匹配者的效率尚未得到充分研究。虽然使用分类参数或课程内存是一种流行的方式，但它会引发大的内存和计算成本。相比之下，迷你批量内的成对深度度量学习将是一个更好的选择。然而，最受欢迎的随机采样方法，众所周知的PK采样器，对深度度量学习不是信息性和有效的。虽然在线硬示例挖掘在一定程度上提高了学习效率，但随机采样后迷你批次仍然有限。这激发了我们在数据采样阶段之前探讨了先前使用硬示例挖掘。为此，在本文中，我们提出了一种有效的跨批量采样方法，称为图形采样（GS），用于大规模深度度量学习。基本思想是为每个时代开始的所有类构建最近的邻居关系图。然后，每个迷你批处理由随机选择的类和其最近的邻类组成，以便为学习提供信息和具有挑战性的例子。与适应的竞争性基线一起，我们在更广泛的人中改善了先前的最先进状态，在MAP中最明显重新鉴定，高达24％和13.8％。此外，所提出的方法还优于竞争性基线在地图中排名-1和5.3％的竞争性基线。同时，培训时间明显减少了多达五次，例如五次。在具有8,000个身份的大型数据集中培训12.2小时至2.3小时。代码可在https://github.com/shengcailiao/qaconv获得。

Recent years witnessed the breakthrough of face recognition with deep convolutional neural networks. Dozens of papers in the field of FR are published every year. Some of them were applied in the industrial community and played an important role in human life such as device unlock, mobile payment, and so on. This paper provides an introduction to face recognition, including its history, pipeline, algorithms based on conventional manually designed features or deep learning, mainstream training, evaluation datasets, and related applications. We have analyzed and compared state-of-the-art works as many as possible, and also carefully designed a set of experiments to find the effect of backbone size and data distribution. This survey is a material of the tutorial named The Practical Face Recognition Technology in the Industrial World in the FG2023.

横梁面部识别（CFR）旨在识别个体，其中比较面部图像源自不同的感测模式，例如红外与可见的。虽然CFR由于与模态差距相关的面部外观的显着变化，但CFR具有比经典的面部识别更具挑战性，但它在具有有限或挑战的照明的场景中，以及在呈现攻击的情况下，它是优越的。与卷积神经网络（CNNS）相关的人工智能最近的进展使CFR的显着性能提高了。由此激励，这项调查的贡献是三倍。我们提供CFR的概述，目标是通过首先正式化CFR然后呈现具体相关的应用来比较不同光谱中捕获的面部图像。其次，我们探索合适的谱带进行识别和讨论最近的CFR方法，重点放在神经网络上。特别是，我们提出了提取和比较异构特征以及数据集的重新访问技术。我们枚举不同光谱和相关算法的优势和局限性。最后，我们讨论了研究挑战和未来的研究线。

Occluded person re-identification (ReID) is a person retrieval task which aims at matching occluded person images with holistic ones. For addressing occluded ReID, part-based methods have been shown beneficial as they offer fine-grained information and are well suited to represent partially visible human bodies. However, training a part-based model is a challenging task for two reasons. Firstly, individual body part appearance is not as discriminative as global appearance (two distinct IDs might have the same local appearance), this means standard ReID training objectives using identity labels are not adapted to local feature learning. Secondly, ReID datasets are not provided with human topographical annotations. In this work, we propose BPBreID, a body part-based ReID model for solving the above issues. We first design two modules for predicting body part attention maps and producing body part-based features of the ReID target. We then propose GiLt, a novel training scheme for learning part-based representations that is robust to occlusions and non-discriminative local appearance. Extensive experiments on popular holistic and occluded datasets show the effectiveness of our proposed method, which outperforms state-of-the-art methods by 0.7% mAP and 5.6% rank-1 accuracy on the challenging Occluded-Duke dataset. Our code is available at https://github.com/VlSomers/bpbreid.

NIR到VIS的面部识别是通过提取域不变特征来识别两个不同域的面。但是，由于两个不同的领域特征以及缺乏NIR FACE数据集，这是一个具有挑战性的问题。为了在使用现有面部识别模型时减少域差异，我们提出了一个“关系模块”，它可以简单地添加到任何面部识别模型中。从面部图像中提取的本地功能包含面部每个组件的信息。基于两个不同的域特征，使用本地特征之间的关系比以原样的方式使用它更具域名。除了这些关系外，位置信息，例如从嘴唇到下巴到眼睛到眼睛到眼睛的距离，还提供域不变的信息。在我们的关系模块中，关系层隐含地捕获关系，并协调层对位置信息进行建模。此外，我们提出的三重态损失和有条件的边缘损失减少了训练中类内部的变化，并导致了进一步的改进。与一般面部识别模型不同，我们的附加模块无需使用大型数据集进行预训练。所提出的模块仅使用CASIA NIR-VIS 2.0数据库进行微调。使用拟议的模块，我们达到了14.81％的排名1精度和15.47％的验证率，为0.1％的验证率与两个基线模型相比。

图像分辨率或一般图像质量在当今面部识别系统的性能中起着至关重要的作用。为了解决这个问题，我们提出了一种流行的三胞胎损失的新型组合，以通过微调现有面部识别模型来提高与图像分辨率的鲁棒性。随着八度损失，我们利用高分辨率图像及其合成下采样变体之间的关系与其身份标签共同采样。通过我们的方法对几种最先进的方法进行微调证明，我们可以在各种数据集上显着提高跨分辨率（高低分辨率）面部验证的性能，而不会有意义地加剧高高度的性能分辨率图像。我们的方法应用于FaceTransFormer网络，在挑战性的XQLFW数据集上达到95.12％的面对验证精度，同时在LFW数据库上达到99.73％。此外，低到低面验证精度从我们的方法中受益。我们发布我们的代码，以允许将OCTUPLET损失的无缝集成到现有框架中。

学习歧视性面部特征在建立高性能面部识别模型方面发挥着重要作用。最近的最先进的面部识别解决方案，提出了一种在常用的分类损失函数，Softmax损失中纳入固定的惩罚率，通过最大限度地减少级别的变化来增加面部识别模型的辨别力并最大化级别的帧间变化。边缘惩罚Softmax损失，如arcFace和Cosface，假设可以使用固定的惩罚余量同样地学习不同身份之间的测地距。然而，这种学习目标对于具有不一致的间帧内变化的真实数据并不是现实的，这可能限制了面部识别模型的判别和概括性。在本文中，我们通过提出弹性罚款损失（弹性面）来放松固定的罚款边缘约束，这允许在推动阶级可分离性中灵活性。主要思想是利用从每个训练迭代中的正常分布中汲取的随机保证金值。这旨在提供决策边界机会，以提取和缩回，以允许灵活的类别可分离学习的空间。我们展示了在大量主流基准上使用相同的几何变换，展示了我们的弹性面损失和COSFace损失的优势。从更广泛的角度来看，我们的弹性面在九个主流基准中提出了最先进的面部识别性能。