在这项工作中，我们提出了一种超大形态器，一种基于变压器的模型，用于几次学习，直接从支持样品产生卷积神经网络（CNN）的权重。由于小生成的CNN模型对特定任务的依赖性由高容量变压器模型编码，因此我们有效地将大型任务空间的复杂性与各个任务的复杂性分离。我们的方法对于小目标CNN架构特别有效，其中学习固定的通用任务无关的嵌入不是最佳的，并且在关于任务的信息可以调制所有模型参数时实现更好的性能。对于较大的模型，我们发现单独生成最后一层允许我们产生比使用最先进的方法获得的竞争或更好的结果，同时端到端可分辨率。最后，我们将我们的方法扩展到一个半监督的政权，利用支持集中的未标记样本，进一步提高少量射击性能。

在新课程训练时，几乎没有射击学习（FSL）方法通常假设具有准确标记的样品的清洁支持集。这个假设通常可能是不现实的：支持集，无论多么小，仍然可能包括标签错误的样本。因此，对标签噪声的鲁棒性对于FSL方法是实用的，但是这个问题令人惊讶地在很大程度上没有探索。为了解决FSL设置中标签错误的样品，我们做出了一些技术贡献。 （1）我们提供了简单而有效的特征聚合方法，改善了流行的FSL技术Protonet使用的原型。 （2）我们描述了一种嘈杂的噪声学习的新型变压器模型（TRANFS）。 TRANFS利用变压器的注意机制称重标记为错误的样品。 （3）最后，我们对迷你胶原和tieredimagenet的嘈杂版本进行了广泛的测试。我们的结果表明，TRANFS与清洁支持集的领先FSL方法相对应，但到目前为止，在存在标签噪声的情况下，它们的表现优于它们。

很少有图像分类是一个具有挑战性的问题，旨在仅基于少量培训图像来达到人类的识别水平。少数图像分类的一种主要解决方案是深度度量学习。这些方法是，通过将看不见的样本根据距离的距离进行分类，可在强大的深神经网络中学到的嵌入空间中看到的样品，可以避免以少数图像分类的少数训练图像过度拟合，并实现了最新的图像表现。在本文中，我们提供了对深度度量学习方法的最新审查，以进行2018年至2022年的少量图像分类，并根据度量学习的三个阶段将它们分为三组，即学习功能嵌入，学习课堂表示和学习距离措施。通过这种分类法，我们确定了他们面临的不同方法和问题的新颖性。我们通过讨论当前的挑战和未来趋势进行了少量图像分类的讨论。

Few-shot classification aims to recognize unlabeled samples from unseen classes given only few labeled samples. The unseen classes and low-data problem make few-shot classification very challenging. Many existing approaches extracted features from labeled and unlabeled samples independently, as a result, the features are not discriminative enough. In this work, we propose a novel Cross Attention Network to address the challenging problems in few-shot classification. Firstly, Cross Attention Module is introduced to deal with the problem of unseen classes. The module generates cross attention maps for each pair of class feature and query sample feature so as to highlight the target object regions, making the extracted feature more discriminative. Secondly, a transductive inference algorithm is proposed to alleviate the low-data problem, which iteratively utilizes the unlabeled query set to augment the support set, thereby making the class features more representative. Extensive experiments on two benchmarks show our method is a simple, effective and computationally efficient framework and outperforms the state-of-the-arts.

Few-shot learning has become essential for producing models that generalize from few examples. In this work, we identify that metric scaling and metric task conditioning are important to improve the performance of few-shot algorithms. Our analysis reveals that simple metric scaling completely changes the nature of few-shot algorithm parameter updates. Metric scaling provides improvements up to 14% in accuracy for certain metrics on the mini-Imagenet 5-way 5-shot classification task. We further propose a simple and effective way of conditioning a learner on the task sample set, resulting in learning a task-dependent metric space. Moreover, we propose and empirically test a practical end-to-end optimization procedure based on auxiliary task co-training to learn a task-dependent metric space. The resulting few-shot learning model based on the task-dependent scaled metric achieves state of the art on mini-Imagenet. We confirm these results on another few-shot dataset that we introduce in this paper based on CIFAR100. Our code is publicly available at https://github.com/ElementAI/TADAM.

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.

很少有视觉识别是指从一些标记实例中识别新颖的视觉概念。通过将查询表示形式与类表征进行比较以预测查询实例的类别，许多少数射击的视觉识别方法采用了基于公制的元学习范式。但是，当前基于度量的方法通常平等地对待所有实例，因此通常会获得有偏见的类表示，考虑到并非所有实例在总结了类级表示的实例级表示时都同样重要。例如，某些实例可能包含无代表性的信息，例如过多的背景和无关概念的信息，这使结果偏差。为了解决上述问题，我们提出了一个新型的基于公制的元学习框架，称为实例自适应类别表示网络（ICRL-net），以进行几次视觉识别。具体而言，我们开发了一个自适应实例重新平衡网络，具有在生成班级表示，通过学习和分配自适应权重的不同实例中的自适应权重时，根据其在相应类的支持集中的相对意义来解决偏见的表示问题。此外，我们设计了改进的双线性实例表示，并结合了两个新型的结构损失，即，阶层内实例聚类损失和阶层间表示区分损失，以进一步调节实例重估过程并完善类表示。我们对四个通常采用的几个基准测试：Miniimagenet，Tieredimagenet，Cifar-FS和FC100数据集进行了广泛的实验。与最先进的方法相比，实验结果证明了我们的ICRL-NET的优势。

几乎没有学习方法的目的是训练模型，这些模型可以根据少量数据轻松适应以前看不见的任务。最受欢迎，最优雅的少学习方法之一是模型敏捷的元学习（MAML）。这种方法背后的主要思想是学习元模型的一般权重，该权重进一步适应了少数梯度步骤中的特定问题。但是，该模型的主要限制在于以下事实：更新过程是通过基于梯度的优化实现的。因此，MAML不能总是在一个甚至几个梯度迭代中将权重修改为基本水平。另一方面，使用许多梯度步骤会导致一个复杂且耗时的优化程序，这很难在实践中训练，并且可能导致过度拟合。在本文中，我们提出了HyperMAML，这是MAML的新型概括，其中更新过程的训练也是模型的一部分。也就是说，在HyperMAML中，我们没有使用梯度下降来更新权重，而是为此目的使用可训练的超级净机。因此，在此框架中，该模型可以生成重大更新，其范围不限于固定数量的梯度步骤。实验表明，超型MAML始终胜过MAML，并且在许多标准的几次学习基准测试基准中与其他最先进的技术相当。

元学习方法旨在构建能够快速适应低数据制度的新任务的学习算法。这种算法的主要基准之一是几次学习问题。在本文中，我们调查了在培训期间采用多任务方法的标准元学习管道的修改。该提出的方法同时利用来自常见损​​失函数中的几个元训练任务的信息。每个任务在损耗功能中的影响由相应的重量控制。正确优化这些权重可能对整个模型的训练产生很大影响，并且可能会提高测试时间任务的质量。在这项工作中，我们提出并调查了使用同时扰动随机近似（SPSA）方法的方法的使用方法，用于元列车任务权重优化。我们还将提出的算法与基于梯度的方法进行了比较，发现随机近似表明了测试时间最大的质量增强。提出的多任务修改可以应用于使用元学习管道的几乎所有方法。在本文中，我们研究了这种修改对CiFar-FS，FC100，TieredimAgenet和MiniimAgenet几秒钟学习基准的原型网络和模型 - 不可知的元学习算法。在这些实验期间，多任务修改已经证明了对原始方法的改进。所提出的SPSA跟踪算法显示了对最先进的元学习方法具有竞争力的最大精度提升。我们的代码可在线获取。

最近，已经观察到，转移学习解决方案可能是我们解决许多少量学习基准的全部 - 因此提出了有关何时以及如何部署元学习算法的重要问题。在本文中，我们试图通过1.提出一个新颖的指标（多样性系数）来阐明这些问题，以测量几次学习基准和2.的任务多样性。 ）并在公平条件下进行学习（相同的体系结构，相同的优化器和所有经过培训的模型）。使用多样性系数，我们表明流行的迷你胶原和Cifar-fs几乎没有学习基准的多样性低。这种新颖的洞察力将转移学习解决方案比在公平比较的低多样性方面的元学习解决方案更好。具体而言，我们从经验上发现，低多样性系数与转移学习和MAML学习解决方案之间的高相似性在元测试时间和分类层相似性方面（使用基于特征的距离指标，例如SVCCA，PWCCA，CKA和OPD） ）。为了进一步支持我们的主张，我们发现这种元测试的准确性仍然存在，即使模型大小变化也是如此。因此，我们得出的结论是，在低多样性制度中，MAML和转移学习在公平比较时具有等效的元检验性能。我们也希望我们的工作激发了对元学习基准测试基准的更周到的结构和定量评估。

Modern machine learning requires system designers to specify aspects of the learning pipeline, such as losses, architectures, and optimizers. Meta-learning, or learning-to-learn, instead aims to learn those aspects, and promises to unlock greater capabilities with less manual effort. One particularly ambitious goal of meta-learning is to train general-purpose in-context learning algorithms from scratch, using only black-box models with minimal inductive bias. Such a model takes in training data, and produces test-set predictions across a wide range of problems, without any explicit definition of an inference model, training loss, or optimization algorithm. In this paper we show that Transformers and other black-box models can be meta-trained to act as general-purpose in-context learners. We characterize phase transitions between algorithms that generalize, algorithms that memorize, and algorithms that fail to meta-train at all, induced by changes in model size, number of tasks, and meta-optimization. We further show that the capabilities of meta-trained algorithms are bottlenecked by the accessible state size (memory) determining the next prediction, unlike standard models which are thought to be bottlenecked by parameter count. Finally, we propose practical interventions such as biasing the training distribution that improve the meta-training and meta-generalization of general-purpose learning algorithms.

epiSodic学习是对几枪学习感兴趣的研究人员和从业者的流行练习。它包括在一系列学习问题（或剧集）中组织培训，每个人分为小型训练和验证子集，以模仿评估期间遇到的情况。但这总是必要吗？在本文中，我们调查了在集发作的级别使用非参数方法，例如最近邻居等方法的焦点学习的有用性。对于这些方法，我们不仅展示了广州学习的限制是如何不必要的，而是他们实际上导致利用培训批次的数据低效方式。我们通过匹配和原型网络进行广泛的消融实验，其中两个最流行的方法在集中的级别使用非参数方法。他们的“非焦化”对应物具有很大的更简单，具有较少的近似参数，并在多个镜头分类数据集中提高它们的性能。

元学习已成为几乎没有图像分类的实用方法，在该方法中，“学习分类器的策略”是在标记的基础类别上进行元学习的，并且可以应用于具有新颖类的任务。我们删除了基类标签的要求，并通过无监督的元学习（UML）学习可通用的嵌入。具体而言，任务发作是在元训练过程中使用未标记的基本类别的数据增强构建的，并且我们将基于嵌入式的分类器应用于新的任务，并在元测试期间使用标记的少量示例。我们观察到两个元素在UML中扮演着重要角色，即进行样本任务和衡量实例之间的相似性的方法。因此，我们获得了具有两个简单修改的​​强基线 - 一个足够的采样策略，每情节有效地构建多个任务以及半分解的相似性。然后，我们利用来自两个方向的任务特征以获得进一步的改进。首先，合成的混淆实例被合并以帮助提取更多的判别嵌入。其次，我们利用额外的特定任务嵌入转换作为元训练期间的辅助组件，以促进预先适应的嵌入式的概括能力。几乎没有学习基准的实验证明，我们的方法比以前的UML方法优于先前的UML方法，并且比其监督变体获得了可比甚至更好的性能。

随着深度学习技术的快速发展和计算能力的提高，深度学习已广泛应用于高光谱图像（HSI）分类领域。通常，深度学习模型通常包含许多可训练参数，并且需要大量标记的样品来实现最佳性能。然而，关于HSI分类，由于手动标记的难度和耗时的性质，大量标记的样本通常难以获取。因此，许多研究工作侧重于建立一个少数标记样本的HSI分类的深层学习模型。在本文中，我们专注于这一主题，并对相关文献提供系统审查。具体而言，本文的贡献是双重的。首先，相关方法的研究进展根据学习范式分类，包括转移学习，积极学习和少量学习。其次，已经进行了许多具有各种最先进的方法的实验，总结了结果以揭示潜在的研究方向。更重要的是，虽然深度学习模型（通常需要足够的标记样本）和具有少量标记样本的HSI场景之间存在巨大差距，但是通过深度学习融合，可以很好地表征小样本集的问题方法和相关技术，如转移学习和轻量级模型。为了再现性，可以在HTTPS://github.com/shuguoj/hsi-classification中找到纸张中评估的方法的源代码.git。

Learning with limited data is a key challenge for visual recognition. Many few-shot learning methods address this challenge by learning an instance embedding function from seen classes and apply the function to instances from unseen classes with limited labels. This style of transfer learning is task-agnostic: the embedding function is not learned optimally discriminative with respect to the unseen classes, where discerning among them leads to the target task. In this paper, we propose a novel approach to adapt the instance embeddings to the target classification task with a set-to-set function, yielding embeddings that are task-specific and are discriminative. We empirically investigated various instantiations of such set-to-set functions and observed the Transformer is most effective -as it naturally satisfies key properties of our desired model. We denote this model as FEAT (few-shot embedding adaptation w/ Transformer) and validate it on both the standard few-shot classification benchmark and four extended few-shot learning settings with essential use cases, i.e., cross-domain, transductive, generalized few-shot learning, and low-shot learning. It archived consistent improvements over baseline models as well as previous methods, and established the new stateof-the-art results on two benchmarks.

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.

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

Transformers have become the state-of-the-art neural network architecture across numerous domains of machine learning. This is partly due to their celebrated ability to transfer and to learn in-context based on few examples. Nevertheless, the mechanisms by which Transformers become in-context learners are not well understood and remain mostly an intuition. Here, we argue that training Transformers on auto-regressive tasks can be closely related to well-known gradient-based meta-learning formulations. We start by providing a simple weight construction that shows the equivalence of data transformations induced by 1) a single linear self-attention layer and by 2) gradient-descent (GD) on a regression loss. Motivated by that construction, we show empirically that when training self-attention-only Transformers on simple regression tasks either the models learned by GD and Transformers show great similarity or, remarkably, the weights found by optimization match the construction. Thus we show how trained Transformers implement gradient descent in their forward pass. This allows us, at least in the domain of regression problems, to mechanistically understand the inner workings of optimized Transformers that learn in-context. Furthermore, we identify how Transformers surpass plain gradient descent by an iterative curvature correction and learn linear models on deep data representations to solve non-linear regression tasks. Finally, we discuss intriguing parallels to a mechanism identified to be crucial for in-context learning termed induction-head (Olsson et al., 2022) and show how it could be understood as a specific case of in-context learning by gradient descent learning within Transformers.

标记数据通常昂贵且耗时，特别是对于诸如对象检测和实例分割之类的任务，这需要对图像的密集标签进行密集的标签。虽然几张拍摄对象检测是关于培训小说中的模型（看不见的）对象类具有很少的数据，但它仍然需要在许多标记的基础（见）类的课程上进行训练。另一方面，自我监督的方法旨在从未标记数据学习的学习表示，该数据转移到诸如物体检测的下游任务。结合几次射击和自我监督的物体检测是一个有前途的研究方向。在本调查中，我们审查并表征了几次射击和自我监督对象检测的最新方法。然后，我们给我们的主要外卖，并讨论未来的研究方向。https://gabrielhuang.github.io/fsod-survey/的项目页面

Continual Learning (CL) is a field dedicated to devise algorithms able to achieve lifelong learning. Overcoming the knowledge disruption of previously acquired concepts, a drawback affecting deep learning models and that goes by the name of catastrophic forgetting, is a hard challenge. Currently, deep learning methods can attain impressive results when the data modeled does not undergo a considerable distributional shift in subsequent learning sessions, but whenever we expose such systems to this incremental setting, performance drop very quickly. Overcoming this limitation is fundamental as it would allow us to build truly intelligent systems showing stability and plasticity. Secondly, it would allow us to overcome the onerous limitation of retraining these architectures from scratch with the new updated data. In this thesis, we tackle the problem from multiple directions. In a first study, we show that in rehearsal-based techniques (systems that use memory buffer), the quantity of data stored in the rehearsal buffer is a more important factor over the quality of the data. Secondly, we propose one of the early works of incremental learning on ViTs architectures, comparing functional, weight and attention regularization approaches and propose effective novel a novel asymmetric loss. At the end we conclude with a study on pretraining and how it affects the performance in Continual Learning, raising some questions about the effective progression of the field. We then conclude with some future directions and closing remarks.