Human behavior understanding requires looking at minute details in the large context of a scene containing multiple input modalities. It is necessary as it allows the design of more human-like machines. While transformer approaches have shown great improvements, they face multiple challenges such as lack of data or background noise. To tackle these, we introduce the Forced Attention (FAt) Transformer which utilize forced attention with a modified backbone for input encoding and a use of additional inputs. In addition to improving the performance on different tasks and inputs, the modification requires less time and memory resources. We provide a model for a generalised feature extraction for tasks concerning social signals and behavior analysis. Our focus is on understanding behavior in videos where people are interacting with each other or talking into the camera which simulates the first person point of view in social interaction. FAt Transformers are applied to two downstream tasks: personality recognition and body language recognition. We achieve state-of-the-art results for Udiva v0.5, First Impressions v2 and MPII Group Interaction datasets. We further provide an extensive ablation study of the proposed architecture.

人格计算和情感计算最近在许多研究领域获得了兴趣。任务的数据集通常具有视频，音频，语言和生物信号等多种方式。在本文中，我们提出了一种灵活的型号，用于利用所有可用数据的任务。该任务涉及复杂的关系，并避免使用大型模型进行视频处理，我们提出了使用行为编码，该行为编码具有对模型的最小变化的性能提升性能。近期使用变压器的横向感到流行，并且用于融合不同的方式。由于可能存在长期关系，因此不希望将输入破坏到块中，因此所提出的模型将整个输入处理在一起。我们的实验表明了上述每个贡献的重要性

视觉变压器正在成为解决计算机视觉问题的强大工具。最近的技术还证明了超出图像域之外的变压器来解决许多与视频相关的任务的功效。其中，由于其广泛的应用，人类的行动识别是从研究界受到特别关注。本文提供了对动作识别的视觉变压器技术的首次全面调查。我们朝着这个方向分析并总结了现有文献和新兴文献，同时突出了适应变形金刚以进行动作识别的流行趋势。由于其专业应用，我们将这些方法统称为``动作变压器''。我们的文献综述根据其架构，方式和预期目标为动作变压器提供了适当的分类法。在动作变压器的背景下，我们探讨了编码时空数据，降低维度降低，框架贴片和时空立方体构造以及各种表示方法的技术。我们还研究了变压器层中时空注意的优化，以处理更长的序列，通常通过减少单个注意操作中的令牌数量。此外，我们还研究了不同的网络学习策略，例如自我监督和零局学习，以及它们对基于变压器的行动识别的相关损失。这项调查还总结了在具有动作变压器重要基准的评估度量评分方面取得的进步。最后，它提供了有关该研究方向的挑战，前景和未来途径的讨论。

Biological systems perceive the world by simultaneously processing high-dimensional inputs from modalities as diverse as vision, audition, touch, proprioception, etc. The perception models used in deep learning on the other hand are designed for individual modalities, often relying on domainspecific assumptions such as the local grid structures exploited by virtually all existing vision models. These priors introduce helpful inductive biases, but also lock models to individual modalities. In this paper we introduce the Perceiver -a model that builds upon Transformers and hence makes few architectural assumptions about the relationship between its inputs, but that also scales to hundreds of thousands of inputs, like ConvNets. The model leverages an asymmetric attention mechanism to iteratively distill inputs into a tight latent bottleneck, allowing it to scale to handle very large inputs. We show that this architecture is competitive with or outperforms strong, specialized models on classification tasks across various modalities: images, point clouds, audio, video, and video+audio. The Perceiver obtains performance comparable to ResNet-50 and ViT on ImageNet without 2D convolutions by directly attending to 50,000 pixels. It is also competitive in all modalities in AudioSet.

与卷积神经网络（CNN）相比，视觉变压器（VIT）正在变得越来越流行和主导技术。作为计算机视觉中苛刻的技术，VIT已成功解决了各种视觉问题，同时着眼于远程关系。在本文中，我们首先介绍自我注意机制的基本概念和背景。接下来，我们提供了最新表现最好的VIT方法的全面概述，该方法在强度和弱点，计算成本以及培训和测试数据集方面描述。我们彻底比较了流行基准数据集上各种VIT算法和大多数代表性CNN方法的性能。最后，我们通过有见地的观察来探索一些局限性，并提供进一步的研究方向。项目页面以及论文集可通过https://github.com/khawar512/vit-survey获得

最近，视力变压器已被证明在多个视力任务中广泛使用基于卷积的方法（CNN）具有竞争力。与CNN相比，变压器的限制性偏差较小。但是，在图像分类设置中，这种灵活性在样本效率方面取决于变压器需要成像尺度训练。这个概念已转移到视频中，其中尚未在低标记或半监视设置中探索用于视频分类的变压器。我们的工作从经验上探讨了视频分类的低数据制度，发现与CNN相比，变形金刚在低标记的视频设置中表现出色。我们专门评估了两个对比的视频数据集（Kinetics-400和Somethingsomething-v2）的视频视觉变压器，并进行彻底的分析和消融研究，以使用视频变压器体系结构的主要特征来解释这一观察结果。我们甚至表明，仅使用标记的数据，变形金刚显着优于复杂的半监督CNN方法，这些方法也利用了大规模未标记的数据。我们的实验告知我们的建议，即半监督的学习视频工作应该考虑将来使用视频变压器。

Astounding results from Transformer models on natural language tasks have intrigued the vision community to study their application to computer vision problems. Among their salient benefits, Transformers enable modeling long dependencies between input sequence elements and support parallel processing of sequence as compared to recurrent networks e.g., Long short-term memory (LSTM). Different from convolutional networks, Transformers require minimal inductive biases for their design and are naturally suited as set-functions. Furthermore, the straightforward design of Transformers allows processing multiple modalities (e.g., images, videos, text and speech) using similar processing blocks and demonstrates excellent scalability to very large capacity networks and huge datasets. These strengths have led to exciting progress on a number of vision tasks using Transformer networks. This survey aims to provide a comprehensive overview of the Transformer models in the computer vision discipline. We start with an introduction to fundamental concepts behind the success of Transformers i.e., self-attention, large-scale pre-training, and bidirectional feature encoding. We then cover extensive applications of transformers in vision including popular recognition tasks (e.g., image classification, object detection, action recognition, and segmentation), generative modeling, multi-modal tasks (e.g., visual-question answering, visual reasoning, and visual grounding), video processing (e.g., activity recognition, video forecasting), low-level vision (e.g., image super-resolution, image enhancement, and colorization) and 3D analysis (e.g., point cloud classification and segmentation). We compare the respective advantages and limitations of popular techniques both in terms of architectural design and their experimental value. Finally, we provide an analysis on open research directions and possible future works. We hope this effort will ignite further interest in the community to solve current challenges towards the application of transformer models in computer vision.

肢体语言是一种引人注目的社交信号，其自动分析可以大大提高人工智能系统，以理解和积极参与社交互动。尽管计算机视觉在诸如头部和身体姿势估计之类的低级任务中取得了令人印象深刻的进步，但探索诸如示意，修饰或摸索之类的更微妙行为的发现尚未得到很好的探索。在本文中，我们介绍了BBSI，这是复杂的身体行为的第一组注释，嵌入了小组环境中的连续社交互动中。根据心理学的先前工作，我们在MpiigroupContraction数据集中手动注释了26个小时的自发人类行为，并具有15种不同的肢体语言类别。我们介绍了所得数据集的全面描述性统计数据以及注释质量评估的结果。为了自动检测这些行为，我们适应了金字塔扩张的注意网络（PDAN），这是一种最新的人类动作检测方法。我们使用四个空间特征的四种变体作为PDAN的输入进行实验：两流膨胀的3D CNN，颞段网络，时间移位模块和SWIN变压器。结果是有希望的，这表明了这项艰巨的任务改进的好空间。 BBSI代表了自动理解社会行为的难题中的关键作品，研究界完全可以使用。

Transformer models have shown great success handling long-range interactions, making them a promising tool for modeling video. However they lack inductive biases and scale quadratically with input length. These limitations are further exacerbated when dealing with the high dimensionality introduced with the temporal dimension. While there are surveys analyzing the advances of Transformers for vision, none focus on an in-depth analysis of video-specific designs. In this survey we analyze main contributions and trends of works leveraging Transformers to model video. Specifically, we delve into how videos are handled as input-level first. Then, we study the architectural changes made to deal with video more efficiently, reduce redundancy, re-introduce useful inductive biases, and capture long-term temporal dynamics. In addition we provide an overview of different training regimes and explore effective self-supervised learning strategies for video. Finally, we conduct a performance comparison on the most common benchmark for Video Transformers (i.e., action classification), finding them to outperform 3D ConvNets even with less computational complexity.

Correctly recognizing the behaviors of children with Autism Spectrum Disorder (ASD) is of vital importance for the diagnosis of Autism and timely early intervention. However, the observation and recording during the treatment from the parents of autistic children may not be accurate and objective. In such cases, automatic recognition systems based on computer vision and machine learning (in particular deep learning) technology can alleviate this issue to a large extent. Existing human action recognition models can now achieve persuasive performance on challenging activity datasets, e.g. daily activity, and sports activity. However, problem behaviors in children with ASD are very different from these general activities, and recognizing these problem behaviors via computer vision is less studied. In this paper, we first evaluate a strong baseline for action recognition, i.e. Video Swin Transformer, on two autism behaviors datasets (SSBD and ESBD) and show that it can achieve high accuracy and outperform the previous methods by a large margin, demonstrating the feasibility of vision-based problem behaviors recognition. Moreover, we propose language-assisted training to further enhance the action recognition performance. Specifically, we develop a two-branch multimodal deep learning framework by incorporating the "freely available" language description for each type of problem behavior. Experimental results demonstrate that incorporating additional language supervision can bring an obvious performance boost for the autism problem behaviors recognition task as compared to using the video information only (i.e. 3.49% improvement on ESBD and 1.46% on SSBD).

在本文中，我们提出了第一个基于变压器的模型，该模型解决了以自我为中心凝视估计的具有挑战性的问题。我们观察到，全局场景上下文和本地视觉信息之间的连接对于从以自我为中心的视频帧进行凝视固定至关重要。为此，我们设计了变压器编码器将全局上下文嵌入为一个附加的视觉令牌，并进一步提出了一种新型的全球 - 本地相关（GLC）模块，以明确模拟全局令牌和每个本地令牌的相关性。我们在两个以自我为中心的视频数据集中验证了我们的模型-EGTEA凝视+和EGO4D。我们的详细消融研究证明了我们方法的好处。此外，我们的方法超过了先前的最新空间。我们还提供了其他可视化，以支持我们的主张，即全球 - 本地相关性是预测以自我为中心视频的凝视固定的关键表示。更多详细信息可以在我们的网站（https://bolinlai.github.io/glc-egogazeest）中找到。

变压器在自然语言处理中的成功最近引起了计算机视觉领域的关注。由于能够学习长期依赖性，变压器已被用作广泛使用的卷积运算符的替代品。事实证明，这种替代者在许多任务中都取得了成功，其中几种最先进的方法依靠变压器来更好地学习。在计算机视觉中，3D字段还见证了使用变压器来增加3D卷积神经网络和多层感知器网络的增加。尽管许多调查都集中在视力中的变压器上，但由于与2D视觉相比，由于数据表示和处理的差异，3D视觉需要特别注意。在这项工作中，我们介绍了针对不同3D视觉任务的100多种变压器方法的系统和彻底审查，包括分类，细分，检测，完成，姿势估计等。我们在3D Vision中讨论了变形金刚的设计，该设计使其可以使用各种3D表示形式处理数据。对于每个应用程序，我们强调了基于变压器的方法的关键属性和贡献。为了评估这些方法的竞争力，我们将它们的性能与12个3D基准测试的常见非转化方法进行了比较。我们通过讨论3D视觉中变压器的不同开放方向和挑战来结束调查。除了提出的论文外，我们的目标是频繁更新最新的相关论文及其相应的实现：https：//github.com/lahoud/3d-vision-transformers。

Group affect refers to the subjective emotion that is evoked by an external stimulus in a group, which is an important factor that shapes group behavior and outcomes. Recognizing group affect involves identifying important individuals and salient objects among a crowd that can evoke emotions. Most of the existing methods are proposed to detect faces and objects using pre-trained detectors and summarize the results into group emotions by specific rules. However, such affective region selection mechanisms are heuristic and susceptible to imperfect faces and objects from the pre-trained detectors. Moreover, faces and objects on group-level images are often contextually relevant. There is still an open question about how important faces and objects can be interacted with. In this work, we incorporate the psychological concept called Most Important Person (MIP). It represents the most noteworthy face in the crowd and has an affective semantic meaning. We propose the Dual-branch Cross-Patch Attention Transformer (DCAT) which uses global image and MIP together as inputs. Specifically, we first learn the informative facial regions produced by the MIP and the global context separately. Then, the Cross-Patch Attention module is proposed to fuse the features of MIP and global context together to complement each other. With parameters less than 10x, the proposed DCAT outperforms state-of-the-art methods on two datasets of group valence prediction, GAF 3.0 and GroupEmoW datasets. Moreover, our proposed model can be transferred to another group affect task, group cohesion, and shows comparable results.

变压器最近展示了改进视觉跟踪算法的明显潜力。尽管如此，基于变压器的跟踪器主要使用变压器熔断并增强由卷积神经网络（CNNS）产生的功能。相比之下，在本文中，我们提出了一个完全基于注意力的变压器跟踪算法，Swin-Cranstormer Tracker（SwintRack）。 SwintRack使用变压器进行特征提取和特征融合，允许目标对象和搜索区域之间的完全交互进行跟踪。为了进一步提高性能，我们调查了全面的不同策略，用于特征融合，位置编码和培训损失。所有这些努力都使SwintRack成为一个简单但坚实的基线。在我们的彻底实验中，SwintRack在leasot上设置了一个新的记录，在4.6 \％的情况下超过4.6 \％，同时仍然以45 fps运行。此外，它达到了最先进的表演，0.483 Suc，0.832 Suc和0.694 Ao，其他具有挑战性的leasot _ {ext} $，trackingnet和got-10k。我们的实施和培训型号可在HTTPS://github.com/litinglin/swintrack获得。

多模式分析最近对情感计算的兴趣很大，因为它可以提高情感识别对孤立的单模态方法的整体准确性。多式联情绪识别最有效的技术有效地利用各种和互补的信息来源，例如面部，声带和生理方式，提供全面的特征表示。在本文中，我们专注于基于视频中提取的面部和声乐方式的融合的尺寸情感识别，其中可以捕获复杂的时空关系。大多数现有的融合技术依赖于经常性网络或传统的注意机制，这些机制没有有效地利用视听（A-V）方式的互补性质。我们介绍了一种跨关注融合方法来提取A-V模式的显着特征，允许准确地预测连续值的价值和唤醒。我们的新的跨关节A-V融合模型有效利用了模态关系。特别地，它计算跨关注权重，以专注于各个模态跨越更贡献的特征，从而组合贡献特征表示，然后将其馈送到完全连接的层以用于预测价和唤醒。所提出的方法的有效性在通过Recolat和疲劳（私人）数据集中的视频上进行了实验验证。结果表明，我们的跨关节A-V融合模型是一种经济高效的方法，优于最先进的融合方法。代码可用：\ url {https://github.com/praveena2j/cross-attentional-av-fusion}

卷积神经网络（CNN）已在许多计算机视觉任务中广泛使用。但是，CNN具有固定的接收场，并且缺乏远程感知的能力，这对于人类的姿势估计至关重要。由于其能够捕获像素之间的远程依赖性的能力，因此最近对计算机视觉应用程序采用了变压器体系结构，并被证明是一种高效的体系结构。我们有兴趣探索其在人类姿势估计中的能力，因此提出了一个基于变压器结构的新型模型，并通过特征金字塔融合结构增强了。更具体地说，我们使用预训练的Swin变压器作为主链，并从输入图像中提取特征，我们利用特征金字塔结构从不同阶段提取特征图。通过将功能融合在一起，我们的模型可以预测关键点热图。我们研究的实验结果表明，与最新的基于CNN的模型相比，提出的基于变压器的模型可以实现更好的性能。

我们使用无卷积的变压器架构提出了一种从未标记数据学习多式式表示的框架。具体而言，我们的视频音频文本变压器（Vatt）将原始信号作为输入提取，提取丰富的多式化表示，以使各种下游任务受益。我们使用多模式对比损失从头划线训练Vatt端到端，并通过视频动作识别，音频事件分类，图像分类和文本到视频检索的下游任务评估其性能。此外，我们通过共享三种方式之间的重量来研究模型 - 无话的单骨架变压器。我们表明，无卷积VATT优于下游任务中的最先进的Convnet架构。特别是，Vatt的视觉变压器在动力学-400上实现82.1％的高精度82.1％，在动力学-600，72.7％的动力学-700上的72.7％，以及时间的时间，新的记录，在避免受监督的预训练时，新的记录。通过从头划伤训练相同的变压器，转移到图像分类导致图像分类导致78.7％的ImageNet精度为64.7％，尽管视频和图像之间的域间差距，我们的模型概括了我们的模型。 Vatt的音雅音频变压器还通过在没有任何监督的预训练的情况下在Audioset上实现39.4％的地图来设置基于波形的音频事件识别的新记录。 Vatt的源代码是公开的。

自动情绪识别（ER）最近由于其在许多实际应用中的潜力而引起了很多兴趣。在这种情况下，已经证明多模式方法可以通过结合多样化和互补的信息来源，从而提高性能（超过单峰方法），从而为嘈杂和缺失的方式提供了一些鲁棒性。在本文中，我们根据从视频中提取的面部和声音方式融合的尺寸ER专注于尺寸，其中探索了互补的视听（A-V）关系，以预测个人在价值空间中的情绪状态。大多数最先进的融合技术都依赖于反复的网络或常规的注意机制，这些机制无法有效利用A-V模式的互补性。为了解决这个问题，我们引入了A-V融合的联合跨注意模型，该模型在A-V模态上提取显着特征，从而可以有效利用模式间关系，同时保留模式内关系。特别是，它根据联合特征表示与单个模式的相关性计算交叉意义权重。通过将联合A-V特征表示形式部署到交叉意见模块中，它有助于同时利用内模式和模态关系，从而显着改善系统的性能，而不是香草交叉意见模块。我们提出的方法的有效性是在Recola和AffWild2数据集的挑战性视频中通过实验验证的。结果表明，我们的跨注意A-V融合模型提供了一种具有成本效益的解决方案，即使模式是嘈杂或不存在的，也可以超越最先进的方法。

In vision and linguistics; the main input modalities are facial expressions, speech patterns, and the words uttered. The issue with analysis of any one mode of expression (Visual, Verbal or Vocal) is that lot of contextual information can get lost. This asks researchers to inspect multiple modalities to get a thorough understanding of the cross-modal dependencies and temporal context of the situation to analyze the expression. This work attempts at preserving the long-range dependencies within and across different modalities, which would be bottle-necked by the use of recurrent networks and adds the concept of delta-attention to focus on local differences per modality to capture the idiosyncrasy of different people. We explore a cross-attention fusion technique to get the global view of the emotion expressed through these delta-self-attended modalities, in order to fuse all the local nuances and global context together. The addition of attention is new to the multi-modal fusion field and currently being scrutinized for on what stage the attention mechanism should be used, this work achieves competitive accuracy for overall and per-class classification which is close to the current state-of-the-art with almost half number of parameters.

目的：在手术规划之前，CT图像中肝血管的分割是必不可少的，并引起了医学图像分析界的广泛兴趣。由于结构复杂，对比度背景下，自动肝脏血管分割仍然特别具有挑战性。大多数相关的研究采用FCN，U-Net和V-Net变体作为骨干。然而，这些方法主要集中在捕获多尺度局部特征，这可能导致由于卷积运营商有限的地区接收领域而产生错误分类的体素。方法：我们提出了一种强大的端到端血管分割网络，通过将SWIN变压器扩展到3D并采用卷积和自我关注的有效组合，提出了一种被称为电感偏置的多头注意船网（IBIMHAV-NET）的稳健端到端血管分割网络。在实践中，我们介绍了Voxel-Wise嵌入而不是修补程序嵌入，以定位精确的肝脏血管素，并采用多尺度卷积运营商来获得局部空间信息。另一方面，我们提出了感应偏置的多头自我关注，其学习从初始化的绝对位置嵌入的归纳偏置相对位置嵌入嵌入。基于此，我们可以获得更可靠的查询和键矩阵。为了验证我们模型的泛化，我们测试具有不同结构复杂性的样本。结果：我们对3Dircadb数据集进行了实验。四种测试病例的平均骰子和敏感性为74.8％和77.5％，超过现有深度学习方法的结果和改进的图形切割方法。结论：拟议模型IBIMHAV-Net提供一种具有交错架构的自动，精确的3D肝血管分割，可更好地利用CT卷中的全局和局部空间特征。它可以进一步扩展到其他临床数据。