Adversarial training is an effective approach to make deep neural networks robust against adversarial attacks. Recently, different adversarial training defenses are proposed that not only maintain a high clean accuracy but also show significant robustness against popular and well studied adversarial attacks such as PGD. High adversarial robustness can also arise if an attack fails to find adversarial gradient directions, a phenomenon known as `gradient masking'. In this work, we analyse the effect of label smoothing on adversarial training as one of the potential causes of gradient masking. We then develop a guided mechanism to avoid local minima during attack optimization, leading to a novel attack dubbed Guided Projected Gradient Attack (G-PGA). Our attack approach is based on a `match and deceive' loss that finds optimal adversarial directions through guidance from a surrogate model. Our modified attack does not require random restarts, large number of attack iterations or search for an optimal step-size. Furthermore, our proposed G-PGA is generic, thus it can be combined with an ensemble attack strategy as we demonstrate for the case of Auto-Attack, leading to efficiency and convergence speed improvements. More than an effective attack, G-PGA can be used as a diagnostic tool to reveal elusive robustness due to gradient masking in adversarial defenses.

Owing to the success of transformer models, recent works study their applicability in 3D medical segmentation tasks. Within the transformer models, the self-attention mechanism is one of the main building blocks that strives to capture long-range dependencies, compared to the local convolutional-based design. However, the self-attention operation has quadratic complexity which proves to be a computational bottleneck, especially in volumetric medical imaging, where the inputs are 3D with numerous slices. In this paper, we propose a 3D medical image segmentation approach, named UNETR++, that offers both high-quality segmentation masks as well as efficiency in terms of parameters and compute cost. The core of our design is the introduction of a novel efficient paired attention (EPA) block that efficiently learns spatial and channel-wise discriminative features using a pair of inter-dependent branches based on spatial and channel attention. Our spatial attention formulation is efficient having linear complexity with respect to the input sequence length. To enable communication between spatial and channel-focused branches, we share the weights of query and key mapping functions that provide a complimentary benefit (paired attention), while also reducing the overall network parameters. Our extensive evaluations on three benchmarks, Synapse, BTCV and ACDC, reveal the effectiveness of the proposed contributions in terms of both efficiency and accuracy. On Synapse dataset, our UNETR++ sets a new state-of-the-art with a Dice Similarity Score of 87.2%, while being significantly efficient with a reduction of over 71% in terms of both parameters and FLOPs, compared to the best existing method in the literature. Code: https://github.com/Amshaker/unetr_plus_plus.

Large-scale multi-modal training with image-text pairs imparts strong generalization to CLIP model. Since training on a similar scale for videos is infeasible, recent approaches focus on the effective transfer of image-based CLIP to the video domain. In this pursuit, new parametric modules are added to learn temporal information and inter-frame relationships which require meticulous design efforts. Furthermore, when the resulting models are learned on videos, they tend to overfit on the given task distribution and lack in generalization aspect. This begs the following question: How to effectively transfer image-level CLIP representations to videos? In this work, we show that a simple Video Fine-tuned CLIP (ViFi-CLIP) baseline is generally sufficient to bridge the domain gap from images to videos. Our qualitative analysis illustrates that the frame-level processing from CLIP image-encoder followed by feature pooling and similarity matching with corresponding text embeddings helps in implicitly modeling the temporal cues within ViFi-CLIP. Such fine-tuning helps the model to focus on scene dynamics, moving objects and inter-object relationships. For low-data regimes where full fine-tuning is not viable, we propose a `bridge and prompt' approach that first uses fine-tuning to bridge the domain gap and then learns prompts on language and vision side to adapt CLIP representations. We extensively evaluate this simple yet strong baseline on zero-shot, base-to-novel generalization, few-shot and fully supervised settings across five video benchmarks. Our code is available at https://github.com/muzairkhattak/ViFi-CLIP.

We propose a very fast frame-level model for anomaly detection in video, which learns to detect anomalies by distilling knowledge from multiple highly accurate object-level teacher models. To improve the fidelity of our student, we distill the low-resolution anomaly maps of the teachers by jointly applying standard and adversarial distillation, introducing an adversarial discriminator for each teacher to distinguish between target and generated anomaly maps. We conduct experiments on three benchmarks (Avenue, ShanghaiTech, UCSD Ped2), showing that our method is over 7 times faster than the fastest competing method, and between 28 and 62 times faster than object-centric models, while obtaining comparable results to recent methods. Our evaluation also indicates that our model achieves the best trade-off between speed and accuracy, due to its previously unheard-of speed of 1480 FPS. In addition, we carry out a comprehensive ablation study to justify our architectural design choices.

在计算机视觉领域，异常检测最近引起了越来越多的关注，这可能是由于其广泛的应用程序从工业生产线上的产品故障检测到视频监视中即将发生的事件检测到在医疗扫描中发现病变。不管域如何，通常将异常检测构架为一级分类任务，其中仅在正常示例上进行学习。整个成功的异常检测方法的家庭基于学习重建掩盖的正常输入（例如贴片，未来帧等），并将重建误差的幅度作为异常水平的指标。与其他基于重建的方法不同，我们提出了一种新颖的自我监督蒙面的卷积变压器块（SSMCTB），该卷积变压器块（SSMCTB）包括基于重建的功能在核心架构层面上。拟议的自我监督块非常灵活，可以在神经网络的任何层上掩盖信息，并与广泛的神经体系结构兼容。在这项工作中，我们扩展了以前的自我监督预测性卷积专注块（SSPCAB），并具有3D掩盖的卷积层，以及用于频道注意的变压器。此外，我们表明我们的块适用于更广泛的任务，在医学图像和热视频中添加异常检测到基于RGB图像和监视视频的先前考虑的任务。我们通过将SSMCTB的普遍性和灵活性整合到多个最先进的神经模型中，以进行异常检测，从而带来了经验结果，可以证实对五个基准的绩效改进：MVTEC AD，BRATS，BRATS，Avenue，Shanghaitech和Thermal和Thermal和Thermal罕见事件。我们在https://github.com/ristea/ssmctb上发布代码和数据作为开源。

现有的基于深度学习的3D对象检测器通常依赖于单个对象的外观，并且不明确注意场景的丰富上下文信息。在这项工作中，我们为3D对象检测（CMR3D）框架提出了上下文化的多阶段完善，该框架将3D场景作为输入，并努力在多个级别上明确整合场景的有用上下文信息，以预测一组对象界限盒以及它们相应的语义标签。为此，我们建议利用一个上下文增强网络，该网络在不同级别的粒度级别上捕获上下文信息，然后是多阶段修补模块，以逐步完善框位置和类预测。大规模ScannETV2基准测试的广泛实验揭示了我们提出的方法的好处，从而使基线的绝对提高了2.0％。除3D对象检测外，我们还研究了CMR3D框架在3D对象计数问题上的有效性。我们的源代码将公开发布。

在过去的十年中，基于深度学习的算法在遥感图像分析的不同领域中广泛流行。最近，最初在自然语言处理中引入的基于变形金刚的体系结构遍布计算机视觉领域，在该字段中，自我发挥的机制已被用作替代流行的卷积操作员来捕获长期依赖性。受到计算机视觉的最新进展的启发，遥感社区还见证了对各种任务的视觉变压器的探索。尽管许多调查都集中在计算机视觉中的变压器上，但据我们所知，我们是第一个对基于遥感中变压器的最新进展进行系统评价的人。我们的调查涵盖了60多种基于变形金刚的60多种方法，用于遥感子方面的不同遥感问题：非常高分辨率（VHR），高光谱（HSI）和合成孔径雷达（SAR）图像。我们通过讨论遥感中变压器的不同挑战和开放问题来结束调查。此外，我们打算在遥感论文中频繁更新和维护最新的变压器，及其各自的代码：https：//github.com/virobo-15/transformer-in-in-remote-sensing

最近在视觉跟踪中成功的关键因素之一是专用基准的可用性。尽管对跟踪研究有很大的受益，但现有的基准并没有与以前相同的难度，而最近的跟踪器的性能则主要是由于（i）引入了更复杂的基于变形金刚的方法，并且（ii）缺乏各种情况，因此缺乏各种情况。不良的可见性，例如恶劣的天气条件，伪装和成像效应。我们介绍了Avist，这是一个专门的基准，用于在具有不良可见性的不同情况下进行视觉跟踪。 Avist包括120个具有80k注释框架的具有挑战性的序列，涵盖了18种不同的方案，这些场景大致分为五个具有42个对象类别的属性。远景的主要贡献是涵盖恶劣天气条件的多样化和挑战性的情况，例如浓雾，大雨和沙尘暴；阻塞效应，包括火，阳光和溅水；不利成像效应，例如，低光；目标效应，包括小目标和干扰物对象以及伪装。我们进一步基准了17个关于Avist的流行和最新跟踪器，对它们跨属性的跟踪性能进行了详细分析，这表明了性能改善的巨大空间。我们认为，远景可以通过补充现有的基准，开发新的创意跟踪解决方案，以继续推动最先进的界限，从而极大地使跟踪社区受益。我们的数据集以及完整的跟踪性能评估可在以下网址提供：https：//github.com/visionml/pytracking

在过去的几年中，基于卷积的神经网络（CNN）的人群计数方法已取得了有希望的结果。但是，对于准确的计数估计，量表变化问题仍然是一个巨大的挑战。在本文中，我们提出了一个多尺度特征聚合网络（MSFANET），可以在某种程度上减轻此问题。具体而言，我们的方法由两个特征聚合模块组成：短聚合（Shortagg）和Skip Contregation（Skipagg）。 Shortagg模块聚集了相邻卷积块的特征。其目的是制作具有从网络底部逐渐融合的不同接收场的功能。 Skipagg模块将具有小型接受场的特征直接传播到具有更大接收场的特征。它的目的是促进特征与大小接收场的融合。尤其是，Skipagg模块引入了Swin Transformer块中的本地自我注意力特征，以结合丰富的空间信息。此外，我们通过考虑不均匀的人群分布来提出基于局部和全球的计数损失。在四个具有挑战性的数据集（Shanghaitech数据集，UCF_CC_50数据集，UCF-QNRF数据集，WorldExpo'10数据集）上进行了广泛的实验，这表明与先前的先前的尚未实行的方法相比，提出的易于实现的MSFANET可以实现有希望的结果。

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。