视觉变压器（VIV）架构最近在各种计算机视觉任务中实现了竞争性能。与卷积神经网络（CNNS）相比，VITS背后的动机之一是较弱的感应偏差。然而，这也使VIT更难以训练。它们需要非常大的培训数据集，重型正常化和强大的数据增强。尽管两种架构之间存在显着差异，但用于培训VITS的数据增强策略主要是从CNN培训继承的。在这项工作中，我们经验性评估了如何在CNN（例如，Reset）对图像分类的VIT架构上进行的不同数据增强策略。我们介绍了一种风格的转移数据增强，称为STYLEAUM，这适合培训VITS，而RANDAURMMENT和AUGMIX通常最适合培训CNNS。我们还发现，除了分类损失之外，在培训VITS时，使用同一图像的多个增强之间的一致性损耗尤为有用。

Modern deep neural networks can achieve high accuracy when the training distribution and test distribution are identically distributed, but this assumption is frequently violated in practice. When the train and test distributions are mismatched, accuracy can plummet. Currently there are few techniques that improve robustness to unforeseen data shifts encountered during deployment. In this work, we propose a technique to improve the robustness and uncertainty estimates of image classifiers. We propose AUGMIX, a data processing technique that is simple to implement, adds limited computational overhead, and helps models withstand unforeseen corruptions. AUGMIX significantly improves robustness and uncertainty measures on challenging image classification benchmarks, closing the gap between previous methods and the best possible performance in some cases by more than half.

视觉变压器（VIV）被涌现为图像识别的最先进的架构。虽然最近的研究表明，VITS比卷积对应物更强大，但我们的实验发现，VITS过度依赖于局部特征（例如，滋扰和质地），并且不能充分使用全局背景（例如，形状和结构）。因此，VIT不能概括到分销，现实世界数据。为了解决这一缺陷，我们通过添加由矢量量化编码器产生的离散令牌来向Vit的输入层提出简单有效的架构修改。与标准的连续像素令牌不同，离散令牌在小扰动下不变，并且单独包含较少的信息，这促进了VITS学习不变的全局信息。实验结果表明，在七种想象中的鲁棒性基准中增加了四个架构变体上的离散表示，在七个想象中心坚固的基准中加强了高达12％的鲁棒性，同时保持了在想象成上的性能。

尽管最近通过剩余网络的代表学习中的自我监督方法取得了进展，但它们仍然对ImageNet分类基准进行了高度的监督学习，限制了它们在性能关键设置中的适用性。在MITROVIC等人的现有理论上洞察中建立2021年，我们提出了RELICV2，其结合了明确的不变性损失，在各种适当构造的数据视图上具有对比的目标。 Relicv2在ImageNet上实现了77.1％的前1个分类准确性，使用线性评估使用Reset50架构和80.6％，具有较大的Reset型号，优于宽边缘以前的最先进的自我监督方法。最值得注意的是，RelicV2是使用一系列标准Reset架构始终如一地始终优先于类似的对比较中的监督基线的第一个表示学习方法。最后，我们表明，尽管使用Reset编码器，Relicv2可与最先进的自我监控视觉变压器相媲美。

积极的数据增强是视觉变压器（VIT）的强大泛化能力的关键组成部分。一种这样的数据增强技术是对抗性培训;然而，许多先前的作品表明，这通常会导致清洁的准确性差。在这项工作中，我们展示了金字塔对抗训练，这是一种简单有效的技术来提高韦维尔的整体性能。我们将其与“匹配”辍学和随机深度正则化配对，这采用了干净和对抗样品的相同辍学和随机深度配置。类似于Advprop的CNNS的改进（不直接适用于VIT），我们的金字塔对抗性训练会破坏分销准确性和vit和相关架构的分配鲁棒性之间的权衡。当Imagenet-1K数据训练时，它导致ImageNet清洁准确性的182美元的vit-B模型的精确度，同时由7美元的稳健性指标同时提高性能，从$ 1.76 \％$至11.45 \％$。我们为Imagenet-C（41.4 MCE），Imagenet-R（$ 53.92 \％$），以及Imagenet-Sketch（41.04美元\％$）的新的最先进，只使用vit-b / 16骨干和我们的金字塔对抗训练。我们的代码将在接受时公开提供。

视觉变压器（VIT）已被证明可以在广泛的视觉应用中获得高度竞争性的性能，例如图像分类，对象检测和语义图像分割。与卷积神经网络相比，通常发现视觉变压器的较弱的电感偏差会在较小的培训数据集上培训时，会增加对模型正则化或数据增强的依赖（简称为“ AUGREG”）。我们进行了一项系统的实证研究，以便更好地了解培训数据，AUGREG，模型大小和计算预算之间的相互作用。作为这项研究的一个结果，我们发现增加的计算和AUGREG的组合可以产生与在数量级上训练的模型相同的训练数据的模型：我们在公共Imagenet-21K数据集中培训各种尺寸的VIT模型在较大的JFT-300M数据集上匹配或超越其对手的培训。

变压器模型在处理各种视觉任务方面表现出了有希望的有效性。但是，与训练卷积神经网络（CNN）模型相比，训练视觉变压器（VIT）模型更加困难，并且依赖于大规模训练集。为了解释这一观察结果，我们做出了一个假设，即\ textit {vit模型在捕获图像的高频组件方面的有效性较小，而不是CNN模型}，并通过频率分析对其进行验证。受这一发现的启发，我们首先研究了现有技术从新的频率角度改进VIT模型的影响，并发现某些技术（例如，randaugment）的成功可以归因于高频组件的更好使用。然后，为了补偿这种不足的VIT模型能力，我们提出了HAT，该HAT可以通过对抗训练直接增强图像的高频组成部分。我们表明，HAT可以始终如一地提高各种VIT模型的性能（例如VIT-B的 +1.2％，Swin-B的 +0.5％），尤其是提高了仅使用Imagenet-的高级模型Volo-D5至87.3％ 1K数据，并且优势也可以维持在分发数据的数据上，并转移到下游任务。该代码可在以下网址获得：https：//github.com/jiawangbai/hat。

Convolutional Neural Networks (CNNs) are commonly thought to recognise objects by learning increasingly complex representations of object shapes. Some recent studies suggest a more important role of image textures. We here put these conflicting hypotheses to a quantitative test by evaluating CNNs and human observers on images with a texture-shape cue conflict. We show that ImageNettrained CNNs are strongly biased towards recognising textures rather than shapes, which is in stark contrast to human behavioural evidence and reveals fundamentally different classification strategies. We then demonstrate that the same standard architecture (ResNet-50) that learns a texture-based representation on ImageNet is able to learn a shape-based representation instead when trained on 'Stylized-ImageNet', a stylized version of ImageNet. This provides a much better fit for human behavioural performance in our well-controlled psychophysical lab setting (nine experiments totalling 48,560 psychophysical trials across 97 observers) and comes with a number of unexpected emergent benefits such as improved object detection performance and previously unseen robustness towards a wide range of image distortions, highlighting advantages of a shape-based representation.

尽管对图像分类任务的表现令人印象深刻，但深网络仍然难以概括其数据的许多常见损坏。为解决此漏洞，事先作品主要专注于提高其培训管道的复杂性，以多样性的名义结合多种方法。然而，在这项工作中，我们逐步回来并遵循原则的方法来实现共同腐败的稳健性。我们提出了一个普遍的数据增强方案，包括最大熵图像变换的简单系列。我们展示了Prime优于现有技术的腐败鲁棒性，而其简单和即插即用性质使其能够与其他方法结合以进一步提升其稳健性。此外，我们分析了对综合腐败图像混合策略的重要性，并揭示了在共同腐败背景下产生的鲁棒性准确性权衡的重要性。最后，我们表明我们的方法的计算效率允许它在线和离线数据增强方案轻松使用。

Modern neural networks are over-parameterized and thus rely on strong regularization such as data augmentation and weight decay to reduce overfitting and improve generalization. The dominant form of data augmentation applies invariant transforms, where the learning target of a sample is invariant to the transform applied to that sample. We draw inspiration from human visual classification studies and propose generalizing augmentation with invariant transforms to soft augmentation where the learning target softens non-linearly as a function of the degree of the transform applied to the sample: e.g., more aggressive image crop augmentations produce less confident learning targets. We demonstrate that soft targets allow for more aggressive data augmentation, offer more robust performance boosts, work with other augmentation policies, and interestingly, produce better calibrated models (since they are trained to be less confident on aggressively cropped/occluded examples). Combined with existing aggressive augmentation strategies, soft target 1) doubles the top-1 accuracy boost across Cifar-10, Cifar-100, ImageNet-1K, and ImageNet-V2, 2) improves model occlusion performance by up to $4\times$, and 3) halves the expected calibration error (ECE). Finally, we show that soft augmentation generalizes to self-supervised classification tasks.

Recently, neural networks purely based on attention were shown to address image understanding tasks such as image classification. These highperforming vision transformers are pre-trained with hundreds of millions of images using a large infrastructure, thereby limiting their adoption.In this work, we produce competitive convolutionfree transformers trained on ImageNet only using a single computer in less than 3 days. Our reference vision transformer (86M parameters) achieves top-1 accuracy of 83.1% (single-crop) on ImageNet with no external data.We also introduce a teacher-student strategy specific to transformers. It relies on a distillation token ensuring that the student learns from the teacher through attention, typically from a convnet teacher. The learned transformers are competitive (85.2% top-1 acc.) with the state of the art on ImageNet, and similarly when transferred to other tasks. We will share our code and models.

While the Transformer architecture has become the de-facto standard for natural language processing tasks, its applications to computer vision remain limited. In vision, attention is either applied in conjunction with convolutional networks, or used to replace certain components of convolutional networks while keeping their overall structure in place. We show that this reliance on CNNs is not necessary and a pure transformer applied directly to sequences of image patches can perform very well on image classification tasks. When pre-trained on large amounts of data and transferred to multiple mid-sized or small image recognition benchmarks (ImageNet, CIFAR-100, VTAB, etc.), Vision Transformer (ViT) attains excellent results compared to state-of-the-art convolutional networks while requiring substantially fewer computational resources to train. 1

Recently, neural networks purely based on attention were shown to address image understanding tasks such as image classification. These highperforming vision transformers are pre-trained with hundreds of millions of images using a large infrastructure, thereby limiting their adoption.In this work, we produce competitive convolution-free transformers by training on Imagenet only. We train them on a single computer in less than 3 days. Our reference vision transformer (86M parameters) achieves top-1 accuracy of 83.1% (single-crop) on ImageNet with no external data.More importantly, we introduce a teacher-student strategy specific to transformers. It relies on a distillation token ensuring that the student learns from the teacher through attention. We show the interest of this token-based distillation, especially when using a convnet as a teacher. This leads us to report results competitive with convnets for both Imagenet (where we obtain up to 85.2% accuracy) and when transferring to other tasks. We share our code and models.

We introduce four new real-world distribution shift datasets consisting of changes in image style, image blurriness, geographic location, camera operation, and more. With our new datasets, we take stock of previously proposed methods for improving out-of-distribution robustness and put them to the test. We find that using larger models and artificial data augmentations can improve robustness on realworld distribution shifts, contrary to claims in prior work. We find improvements in artificial robustness benchmarks can transfer to real-world distribution shifts, contrary to claims in prior work. Motivated by our observation that data augmentations can help with real-world distribution shifts, we also introduce a new data augmentation method which advances the state-of-the-art and outperforms models pretrained with 1000× more labeled data. Overall we find that some methods consistently help with distribution shifts in texture and local image statistics, but these methods do not help with some other distribution shifts like geographic changes. Our results show that future research must study multiple distribution shifts simultaneously, as we demonstrate that no evaluated method consistently improves robustness.

我们提出了一项新的自我监督的预测变压器预测，以进行密集的预测任务。它基于将像素级表示与全局图像表示形式进行比较的对比损失。该策略可产生更好的本地功能，适用于密集的预测任务，而不是基于全球图像表示的对比预训练。此外，我们的方法不会遭受批次大小的减小，因为对比度损失所需的负面示例数量是局部特征数量的顺序。我们证明了训练策略对两个密集预测任务的有效性：语义分割和单眼深度估计。

视觉变压器（VIT）在各种机器视觉问题上表现出令人印象深刻的性能。这些模型基于多头自我关注机制，可以灵活地参加一系列图像修补程序以编码上下文提示。一个重要问题是在给定贴片上参加图像范围内的上下文的这种灵活性是如何促进在自然图像中处理滋扰，例如，严重的闭塞，域移位，空间置换，对抗和天然扰动。我们通过广泛的一组实验来系统地研究了这个问题，包括三个vit家族和具有高性能卷积神经网络（CNN）的比较。我们展示和分析了vit的以下迷恋性质：（a）变压器对严重闭塞，扰动和域移位高度稳健，例如，即使在随机堵塞80％的图像之后，也可以在想象中保持高达60％的前1个精度。内容。 （b）与局部纹理的偏置有抗闭锁的强大性能，与CNN相比，VITS对纹理的偏置显着偏差。当受到适当训练以编码基于形状的特征时，VITS展示与人类视觉系统相当的形状识别能力，以前在文献中无与伦比。 （c）使用VIT来编码形状表示导致准确的语义分割而没有像素级监控的有趣后果。 （d）可以组合从单VIT模型的现成功能，以创建一个功能集合，导致传统和几枪学习范例的一系列分类数据集中的高精度率。我们显示VIT的有效特征是由于自我关注机制可以实现灵活和动态的接受领域。

变压器出现为可视识别的强大工具。除了在广泛的视觉基准上展示竞争性能外，最近的作品还争辩说，变形金刚比卷曲神经网络（CNNS）更强大。令人惊讶的是，我们发现这些结论是从不公平的实验设置中得出的，其中变压器和CNN在不同的尺度上比较，并用不同的训练框架应用。在本文中，我们的目标是在变压器和CNN之间提供第一个公平和深入的比较，重点是鲁棒性评估。通过我们的统一培训设置，我们首先挑战以前的信念，使得在衡量对抗性鲁棒性时越来越多的CNN。更令人惊讶的是，如果他们合理地采用变形金刚的培训食谱，我们发现CNNS可以很容易地作为捍卫对抗性攻击的变形金刚。在关于推广样本的泛化的同时，我们显示了对（外部）大规模数据集的预训练不是对实现变压器来实现比CNN更好的性能的根本请求。此外，我们的消融表明，这种更强大的概括主要受到变压器的自我关注架构本身的影响，而不是通过其他培训设置。我们希望这项工作可以帮助社区更好地理解和基准变压器和CNN的鲁棒性。代码和模型在https://github.com/ytongbai/vits-vs-cnns上公开使用。

在真实世界的机器学习应用中，可靠和安全的系统必须考虑超出标准测试设置精度的性能测量。这些其他目标包括分销（OOD）鲁棒性，预测一致性，对敌人的抵御能力，校准的不确定性估计，以及检测异常投入的能力。然而，提高这些目标的绩效通常是一种平衡行为，即今天的方法无法在不牺牲其他安全轴上的性能的情况下实现。例如，对抗性培训改善了对抗性鲁棒性，但急剧降低了其他分类器性能度量。同样，强大的数据增强和正则化技术往往提高鲁棒性，但损害异常检测，提出了对所有现有安全措施的帕累托改进是可能的。为满足这一挑战，我们设计了利用诸如分数形的图片的自然结构复杂性设计新的数据增强策略，这优于众多基线，靠近帕累托 - 最佳，并圆形提高安全措施。

This paper presents SimCLR: a simple framework for contrastive learning of visual representations. We simplify recently proposed contrastive selfsupervised learning algorithms without requiring specialized architectures or a memory bank. In order to understand what enables the contrastive prediction tasks to learn useful representations, we systematically study the major components of our framework. We show that (1) composition of data augmentations plays a critical role in defining effective predictive tasks, (2) introducing a learnable nonlinear transformation between the representation and the contrastive loss substantially improves the quality of the learned representations, and (3) contrastive learning benefits from larger batch sizes and more training steps compared to supervised learning. By combining these findings, we are able to considerably outperform previous methods for self-supervised and semi-supervised learning on ImageNet. A linear classifier trained on self-supervised representations learned by Sim-CLR achieves 76.5% top-1 accuracy, which is a 7% relative improvement over previous state-ofthe-art, matching the performance of a supervised ResNet-50. When fine-tuned on only 1% of the labels, we achieve 85.8% top-5 accuracy, outperforming AlexNet with 100× fewer labels. 1