在线行动检测旨在基于长期的历史观察结果对当前框架进行准确的行动预测。同时,它需要对在线流视频进行实时推断。在本文中,我们主张一个新颖有效的在线行动检测原则。它仅在一个窗口中更新最新,最古老的历史表示,但重复了已经计算的中间图表。基于这一原则,我们引入了一个基于窗口的级联变压器,带有圆形历史队列,在每个窗口上都进行了多阶段的注意力和级联精炼。我们还探讨了在线操作检测与其脱机行动分段作为辅助任务之间的关联。我们发现,这种额外的监督有助于判别历史的聚类,并充当功能增强,以更好地培训分类器和级联改善。我们提出的方法在三个具有挑战性的数据集Thumos'14,TVSeries和HDD上实现了最新的表演。接受后将可用。
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在视频的每一帧中,流式传输视频识别原因及其动作。良好的流识别模型捕获了长期动态和视频的短期变化。不幸的是,在大多数现有方法中,计算复杂性随所考虑的动力学的长度线性或二次增长。此问题在基于变压器的体系结构中特别明显。为了解决这个问题,我们通过内核镜头重新制定了视频变压器中的跨注意事项,并应用了两种暂时的平滑核:盒子内核或拉普拉斯内核。最终的流动注意力可以从框架到框架重新重新计算,并且仅需要恒定的时间更新每个帧。基于这个想法,我们构建了一种时间平滑变压器Testra,它具有恒定的缓存和计算开销的任意输入。具体而言,它的运行$ 6 \ times $ $ $比基于滑动窗口的同等滑动变压器的运行速度快,在流设置中具有2,048帧。此外,由于时间跨度的增加,Testra在Thumos'14和Epic-Kitchen-100上取得了最新的结果,这是两个标准的在线操作检测和动作预期数据集。 Testra的实时版本优于Thumos'14数据集上的所有事先方法。
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Detection Transformer (DETR) and Deformable DETR have been proposed to eliminate the need for many hand-designed components in object detection while demonstrating good performance as previous complex hand-crafted detectors. However, their performance on Video Object Detection (VOD) has not been well explored. In this paper, we present TransVOD, the first end-to-end video object detection system based on spatial-temporal Transformer architectures. The first goal of this paper is to streamline the pipeline of VOD, effectively removing the need for many hand-crafted components for feature aggregation, e.g., optical flow model, relation networks. Besides, benefited from the object query design in DETR, our method does not need complicated post-processing methods such as Seq-NMS. In particular, we present a temporal Transformer to aggregate both the spatial object queries and the feature memories of each frame. Our temporal transformer consists of two components: Temporal Query Encoder (TQE) to fuse object queries, and Temporal Deformable Transformer Decoder (TDTD) to obtain current frame detection results. These designs boost the strong baseline deformable DETR by a significant margin (2 %-4 % mAP) on the ImageNet VID dataset. TransVOD yields comparable performances on the benchmark of ImageNet VID. Then, we present two improved versions of TransVOD including TransVOD++ and TransVOD Lite. The former fuses object-level information into object query via dynamic convolution while the latter models the entire video clips as the output to speed up the inference time. We give detailed analysis of all three models in the experiment part. In particular, our proposed TransVOD++ sets a new state-of-the-art record in terms of accuracy on ImageNet VID with 90.0 % mAP. Our proposed TransVOD Lite also achieves the best speed and accuracy trade-off with 83.7 % mAP while running at around 30 FPS on a single V100 GPU device. Code and models will be available for further research.
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在线操作检测是一旦在流视频中进行的操作,就可以预测该动作。一个主要的挑战是,该模型无法访问未来,并且必须仅依靠历史,即到目前为止观察到的框架来做出预测。因此,重要的是要强调历史的一部分,这些部分对当前框架的预测更有意义。我们提出了带有背景抑制的封闭历史单元的Gatehub,其中包括一种新颖的位置引导的封闭式跨注意机制,以增强或抑制历史的一部分,因为它们在当前框架预测方面的信息程度。 GateHub进一步建议未来的历史记录(FAH),通过使用后来观察到的框架,使历史特征更具信息性。在一个统一的框架中,GateHub集成了变压器的远程时间建模的能力以及经常性模型选择性编码相关信息的能力。 GateHub还引入了一个背景抑制目标,以进一步减轻与动作框架非常相似的误报背景框架。对三个基准数据集(Thumos,TVSeries和HDD)进行了广泛的验证,这表明GateHub显着胜过所有现有方法,并且比现有最佳工作更有效。此外,与所有需要RGB和光流信息进行预测的现有方法相比,GateHub的无流版本能够以2.8倍的帧速率获得更高或密切的精度。
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时间动作本地化在视频分析中起着重要作用,该视频分析旨在将动作定位和分类在未修剪视频中。先前的方法通常可以预测单个时间尺度的特征空间上的动作。但是,低级量表的时间特征缺乏足够的语义来进行动作分类,而高级尺度则无法提供动作边界的丰富细节。为了解决这个问题,我们建议预测多个颞尺度特征空间的动作。具体而言,我们使用不同尺度的精致特征金字塔将语义从高级尺度传递到低级尺度。此外,为了建立整个视频的长时间尺度,我们使用时空变压器编码器来捕获视频帧的远程依赖性。然后,具有远距离依赖性的精制特征被送入分类器以进行粗糙的动作预测。最后,为了进一步提高预测准确性,我们建议使用框架级别的自我注意模块来完善每个动作实例的分类和边界。广泛的实验表明,所提出的方法可以超越Thumos14数据集上的最先进方法,并在ActivityNet1.3数据集上实现可比性的性能。与A2NET(tip20,avg \ {0.3:0.7 \}),sub-action(csvt2022,avg \ {0.1:0.5 \})和afsd(cvpr21,avg \ {0.3:0.7 \}) ,提出的方法分别可以提高12.6 \%,17.4 \%和2.2 \%
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变压器是一种基于关注的编码器解码器架构,彻底改变了自然语言处理领域。灵感来自这一重大成就,最近在将变形式架构调整到计算机视觉(CV)领域的一些开创性作品,这已经证明了他们对各种简历任务的有效性。依靠竞争力的建模能力,与现代卷积神经网络相比在本文中,我们已经为三百不同的视觉变压器进行了全面的审查,用于三个基本的CV任务(分类,检测和分割),提出了根据其动机,结构和使用情况组织这些方法的分类。 。由于培训设置和面向任务的差异,我们还在不同的配置上进行了评估了这些方法,以便于易于和直观的比较而不是各种基准。此外,我们已经揭示了一系列必不可少的,但可能使变压器能够从众多架构中脱颖而出,例如松弛的高级语义嵌入,以弥合视觉和顺序变压器之间的差距。最后,提出了三个未来的未来研究方向进行进一步投资。
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Temporal action detection (TAD) is extensively studied in the video understanding community by generally following the object detection pipeline in images. However, complex designs are not uncommon in TAD, such as two-stream feature extraction, multi-stage training, complex temporal modeling, and global context fusion. In this paper, we do not aim to introduce any novel technique for TAD. Instead, we study a simple, straightforward, yet must-known baseline given the current status of complex design and low detection efficiency in TAD. In our simple baseline (termed BasicTAD), we decompose the TAD pipeline into several essential components: data sampling, backbone design, neck construction, and detection head. We extensively investigate the existing techniques in each component for this baseline, and more importantly, perform end-to-end training over the entire pipeline thanks to the simplicity of design. As a result, this simple BasicTAD yields an astounding and real-time RGB-Only baseline very close to the state-of-the-art methods with two-stream inputs. In addition, we further improve the BasicTAD by preserving more temporal and spatial information in network representation (termed as PlusTAD). Empirical results demonstrate that our PlusTAD is very efficient and significantly outperforms the previous methods on the datasets of THUMOS14 and FineAction. Meanwhile, we also perform in-depth visualization and error analysis on our proposed method and try to provide more insights on the TAD problem. Our approach can serve as a strong baseline for future TAD research. The code and model will be released at https://github.com/MCG-NJU/BasicTAD.
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动作检测的任务旨在在每个动作实例中同时推论动作类别和终点的本地化。尽管Vision Transformers推动了视频理解的最新进展,但由于在长时间的视频剪辑中,设计有效的架构以进行动作检测是不平凡的。为此,我们提出了一个有效的层次时空时空金字塔变压器(STPT)进行动作检测,这是基于以下事实:变压器中早期的自我注意力层仍然集中在局部模式上。具体而言,我们建议在早期阶段使用本地窗口注意来编码丰富的局部时空时空表示,同时应用全局注意模块以捕获后期的长期时空依赖性。通过这种方式,我们的STPT可以用冗余的大大减少来编码区域和依赖性,从而在准确性和效率之间进行有希望的权衡。例如,仅使用RGB输入,提议的STPT在Thumos14上获得了53.6%的地图,超过10%的I3D+AFSD RGB模型超过10%,并且对使用其他流量的额外流动功能的表现较少,该流量具有31%的GFLOPS ,它是一个有效,有效的端到端变压器框架,用于操作检测。
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用于深度卷积神经网络的视频插值的现有方法,因此遭受其内在限制,例如内部局限性核心权重和受限制的接收领域。为了解决这些问题,我们提出了一种基于变换器的视频插值框架,允许内容感知聚合权重,并考虑具有自我关注操作的远程依赖性。为避免全球自我关注的高计算成本,我们将当地注意的概念引入视频插值并将其扩展到空间域。此外,我们提出了一个节省时间的分离策略,以节省内存使用,这也提高了性能。此外,我们开发了一种多尺度帧合成方案,以充分实现变压器的潜力。广泛的实验证明了所提出的模型对最先进的方法来说,定量和定性地在各种基准数据集上进行定量和定性。
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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.
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基于自我注意力的变压器模型已显示出令人印象深刻的图像分类和对象检测结果,并且最近用于视频理解。受此成功的启发,我们研究了变压器网络在视频中的时间动作本地化的应用。为此,我们提出了ActionFormer,这是一个简单而强大的模型,可在不使用动作建议或依靠预定义的锚点窗口中识别其及时识别其类别并识别其类别。 ActionFormer将多尺度特征表示与局部自我发作相结合,并使用轻加权解码器对每个时刻进行分类并估算相应的动作边界。我们表明,这种精心策划的设计会在先前的工作中进行重大改进。如果没有铃铛和口哨声,ActionFormer在Thumos14上的TIOU = 0.5的地图达到了71.0%的地图,表现优于最佳先前模型的绝对百分比14.1。此外,ActionFormer在ActivityNet 1.3(平均地图36.6%)和Epic-Kitchens 100(+先前工作的平均地图+13.5%)上显示出很强的结果。我们的代码可从http://github.com/happyharrycn/actionformer_release获得。
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自动外科阶段识别在机器人辅助手术中起着重要作用。现有方法忽略了一个关键问题,即外科阶段应该通过学习段级语义来分类,而不是仅仅依赖于框架明智的信息。在本文中,我们提出了一种段 - 细分分层一致性网络(SAHC),用于来自视频的外科阶段识别。关键的想法是提取分层高级语义 - 一致的段,并使用它们来优化由暧昧帧引起的错误预测。为实现它,我们设计一个时间分层网络以生成分层高级段。然后,我们引入分层段帧注意力(SFA)模块,以捕获低级帧和高级段之间的关系。通过通过一致性损耗来规则地规范帧及其对应段的预测,网络可以生成语义 - 一致的段,然后纠正由模糊的低级帧引起的错误分类预测。我们在两个公共外科视频数据集上验证SAHC,即M2CAI16挑战数据集和CholeC80数据集。实验结果表明,我们的方法优于以前的最先进的余量,显着达到M2Cai16的4.1%。代码将在验收时在Github发布。
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时间动作检测(TAD)旨在确定未修剪视频中每个动作实例的语义标签和边界。先前的方法通过复杂的管道来解决此任务。在本文中,我们提出了一个具有简单集的预测管道的端到端时间动作检测变压器(TADTR)。给定一组名为“动作查询”的可学习嵌入,Tadtr可以从每个查询的视频中自适应提取时间上下文,并直接预测动作实例。为了适应TAD的变压器,我们提出了三个改进,以提高其所在地意识。核心是一个时间可变形的注意模块,在视频中有选择地参加一组稀疏的密钥片段。片段的完善机制和动作回归头旨在完善预测实例的边界和信心。 TADTR需要比以前的检测器更低的计算成本,同时保留了出色的性能。作为一个独立的检测器,它在Thumos14(56.7%地图)和HACS段(32.09%地图)上实现了最先进的性能。结合一个额外的动作分类器,它在ActivityNet-1.3上获得了36.75%的地图。我们的代码可在\ url {https://github.com/xlliu7/tadtr}上获得。
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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.
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我们提出了块茎:一种简单的时空视频动作检测解决方案。与依赖于离线演员检测器或手工设计的演员位置假设的现有方法不同,我们建议通过同时执行动作定位和识别从单个表示来直接检测视频中的动作微管。块茎学习一组管芯查询,并利用微调模块来模拟视频剪辑的动态时空性质,其有效地加强了与在时空空间中的演员位置假设相比的模型容量。对于包含过渡状态或场景变更的视频,我们提出了一种上下文意识的分类头来利用短期和长期上下文来加强行动分类,以及用于检测精确的时间动作程度的动作开关回归头。块茎直接产生具有可变长度的动作管,甚至对长视频剪辑保持良好的结果。块茎在常用的动作检测数据集AVA,UCF101-24和JHMDB51-21上优于先前的最先进。
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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。
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虽然变形金机对视频识别任务的巨大潜力具有较强的捕获远程依赖性的强大能力,但它们经常遭受通过对视频中大量3D令牌的自我关注操作引起的高计算成本。在本文中,我们提出了一种新的变压器架构,称为双重格式,可以有效且有效地对视频识别进行时空关注。具体而言,我们的Dualformer将完全时空注意力分层到双级级联级别,即首先在附近的3D令牌之间学习细粒度的本地时空交互,然后捕获查询令牌之间的粗粒度全局依赖关系。粗粒度全球金字塔背景。不同于在本地窗口内应用时空分解或限制关注计算以提高效率的现有方法,我们本地 - 全球分层策略可以很好地捕获短期和远程时空依赖项,同时大大减少了钥匙和值的数量在注意计算提高效率。实验结果表明,对抗现有方法的五个视频基准的经济优势。特别是,Dualformer在动态-400/600上设置了新的最先进的82.9%/ 85.2%,大约1000g推理拖鞋,比具有相似性能的现有方法至少3.2倍。
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时间动作本地化旨在预测未修剪长视频中每个动作实例的边界和类别。基于锚或建议的大多数先前方法忽略了整个视频序列中的全局本地上下文相互作用。此外,他们的多阶段设计无法直接生成动作边界和类别。为了解决上述问题,本文提出了一种新颖的端到端模型,称为自适应感知变压器(简称apperformer)。具体而言,Adaperformer探索了双支球多头的自我发项机制。一个分支会照顾全球感知的关注,该注意力可以模拟整个视频序列并汇总全球相关环境。而其他分支集中于局部卷积转移,以通过我们的双向移动操作来汇总框架内和框架间信息。端到端性质在没有额外步骤的情况下产生视频动作的边界和类别。提供了广泛的实验以及消融研究,以揭示我们设计的有效性。我们的方法在Thumos14数据集上实现了最先进的准确性(根据map@0.5、42.6 \%map@0.7和62.7 \%map@avg),并在活动网络上获得竞争性能, -1.3数据集,平均地图为36.1 \%。代码和型号可在https://github.com/soupero/adaperformer上找到。
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Passive millimeter-wave (PMMW) is a significant potential technique for human security screening. Several popular object detection networks have been used for PMMW images. However, restricted by the low resolution and high noise of PMMW images, PMMW hidden object detection based on deep learning usually suffers from low accuracy and low classification confidence. To tackle the above problems, this paper proposes a Task-Aligned Detection Transformer network, named PMMW-DETR. In the first stage, a Denoising Coarse-to-Fine Transformer (DCFT) backbone is designed to extract long- and short-range features in the different scales. In the second stage, we propose the Query Selection module to introduce learned spatial features into the network as prior knowledge, which enhances the semantic perception capability of the network. In the third stage, aiming to improve the classification performance, we perform a Task-Aligned Dual-Head block to decouple the classification and regression tasks. Based on our self-developed PMMW security screening dataset, experimental results including comparison with State-Of-The-Art (SOTA) methods and ablation study demonstrate that the PMMW-DETR obtains higher accuracy and classification confidence than previous works, and exhibits robustness to the PMMW images of low quality.
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动作检测是一个必不可少的和具有挑战性的任务,特别是对于未经监测视频的密集标记数据集。在这些数据集中,时间关系是复杂的,包括综合动作等挑战和共同发生的动作。为了检测这些复杂视频中的动作,有效地捕获视频中的短期和长期时间信息是至关重要的。为此,我们提出了一种用于动作检测的新型Converransformer网络。该网络包括三个主要组件:(1)时间编码器模块广泛探讨多个时间分辨率的全局和局部时间关系。 (2)时间尺度混频器模块有效地熔化多尺度特征以具有统一的特征表示。 (3)分类模块用于学习实例中心相对位置并预测帧级分类分数。多个数据集的大量实验,包括Charades,TSU和Multithumos,确认了我们所提出的方法的有效性。我们的网络在所有三个数据集上占据了最先进的方法。
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