We propose a new neural network design paradigm Reversible Column Network (RevCol). The main body of RevCol is composed of multiple copies of subnetworks, named columns respectively, between which multi-level reversible connections are employed. Such architectural scheme attributes RevCol very different behavior from conventional networks: during forward propagation, features in RevCol are learned to be gradually disentangled when passing through each column, whose total information is maintained rather than compressed or discarded as other network does. Our experiments suggest that CNN-style RevCol models can achieve very competitive performances on multiple computer vision tasks such as image classification, object detection and semantic segmentation, especially with large parameter budget and large dataset. For example, after ImageNet-22K pre-training, RevCol-XL obtains 88.2% ImageNet-1K accuracy. Given more pre-training data, our largest model RevCol-H reaches 90.0% on ImageNet-1K, 63.8% APbox on COCO detection minival set, 61.0% mIoU on ADE20k segmentation. To our knowledge, it is the best COCO detection and ADE20k segmentation result among pure (static) CNN models. Moreover, as a general macro architecture fashion, RevCol can also be introduced into transformers or other neural networks, which is demonstrated to improve the performances in both computer vision and NLP tasks. We release code and models at https://github.com/megvii-research/RevCol
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与大脑变化相关的阿尔茨海默氏病(AD)和轻度认知障碍(MCI)的评估仍然是一项艰巨的任务。最近的研究表明,多模式成像技术的组合可以更好地反映病理特征,并有助于更准确地诊断AD和MCI。在本文中,我们提出了一种新型的基于张量的多模式特征选择和回归方法,用于诊断和生物标志物对正常对照组的AD和MCI鉴定。具体而言,我们利用张量结构来利用多模式数据中固有的高级相关信息,并研究多线性回归模型中的张量级稀疏性。我们使用三种成像方式(VBM- MRI,FDG-PET和AV45-PET)具有疾病严重程度和认知评分的临床参数来分析ADNI数据的方法的实际优势。实验结果表明,我们提出的方法与疾病诊断的最新方法的优越性能以及疾病特异性区域和与模态相关的差异的鉴定。这项工作的代码可在https://github.com/junfish/bios22上公开获得。
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深度学习通常是饥饿的,并且开发了无监督的域适应性(UDA),以将标记的源域中的知识引入未标记的目标域中。最近,深度自我训练为UDA提供了一种强大的手段,涉及一个预测目标域,然后将自信的预测作为硬伪标记的迭代过程。但是,伪标签通常是不可靠的,因此很容易导致带有传播误差的偏差解决方案。在本文中,我们采用基于能量的模型,并以能量函数最小化目标来限制未标记的目标样品的训练。可以通过简单的附加正规化或基于能量的损失来实现。该框架使我们能够获得基于能量的模型的好处,同时在插件时保持强劲的判别性能。研究了收敛属性及其与分类期望最小化的联系。我们对图像分类的最流行和大规模UDA基准以及语义分割进行了广泛的实验,以证明其通用性和有效性。
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图像DeBlurring旨在恢复模糊图像中的详细纹理信息或结构,这已成为许多计算机视觉任务中必不可少的一步。尽管已经提出了各种方法来处理图像去除问题,但大多数方法将模糊图像视为一个整体,并忽略了不同图像频率的特征。在本文中,我们提出了一种新方法,称为图像脱毛的多尺度频率分离网络(MSFS-NET)。 MSFS-NET将频率分离模块(FSM)引入编码器 - 模块网络体系结构中,以在多个尺度上捕获图像的低频和高频信息。然后,分别设计了一个循环一致性策略和对比度学习模块(CLM),以保留低频信息,并在Deblurring期间恢复高频信息。最后,不同量表的特征是通过跨尺度特征融合模块(CSFFM)融合的。基准数据集的广泛实验表明,所提出的网络可实现最先进的性能。
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本文介绍了一种基于图形的Concionome分析的基于图形的内核学习方法。具体地,我们演示了如何利用图表表示内的自然可用结构来编码内核中的先验知识。我们首先提出了一种矩阵分解,以直接从连接数据的自然对称图表表示中提取结构特征。然后,我们使用它们来导出一个结构悬停的图形内核将被馈送到支持向量机中。拟议的方法具有临床思考的优势。对挑战性HIV疾病分类的定量评估(DTI和FMRI衍生的连接数据)和情感识别(EEG导出的连接数据)任务证明了我们提出的方法对现有技术的卓越性能。结果表明,在情感监管任务期间,相关的EEG结合信息主要在Alpha带中编码。
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Weakly-supervised object localization aims to indicate the category as well as the scope of an object in an image given only the image-level labels. Most of the existing works are based on Class Activation Mapping (CAM) and endeavor to enlarge the discriminative area inside the activation map to perceive the whole object, yet ignore the co-occurrence confounder of the object and context (e.g., fish and water), which makes the model inspection hard to distinguish object boundaries. Besides, the use of CAM also brings a dilemma problem that the classification and localization always suffer from a performance gap and can not reach their highest accuracy simultaneously. In this paper, we propose a casual knowledge distillation method, dubbed KD-CI-CAM, to address these two under-explored issues in one go. More specifically, we tackle the co-occurrence context confounder problem via causal intervention (CI), which explores the causalities among image features, contexts, and categories to eliminate the biased object-context entanglement in the class activation maps. Based on the de-biased object feature, we additionally propose a multi-teacher causal distillation framework to balance the absorption of classification knowledge and localization knowledge during model training. Extensive experiments on several benchmarks demonstrate the effectiveness of KD-CI-CAM in learning clear object boundaries from confounding contexts and addressing the dilemma problem between classification and localization performance.
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Face Anti-spoofing (FAS) is essential to secure face recognition systems from various physical attacks. However, recent research generally focuses on short-distance applications (i.e., phone unlocking) while lacking consideration of long-distance scenes (i.e., surveillance security checks). In order to promote relevant research and fill this gap in the community, we collect a large-scale Surveillance High-Fidelity Mask (SuHiFiMask) dataset captured under 40 surveillance scenes, which has 101 subjects from different age groups with 232 3D attacks (high-fidelity masks), 200 2D attacks (posters, portraits, and screens), and 2 adversarial attacks. In this scene, low image resolution and noise interference are new challenges faced in surveillance FAS. Together with the SuHiFiMask dataset, we propose a Contrastive Quality-Invariance Learning (CQIL) network to alleviate the performance degradation caused by image quality from three aspects: (1) An Image Quality Variable module (IQV) is introduced to recover image information associated with discrimination by combining the super-resolution network. (2) Using generated sample pairs to simulate quality variance distributions to help contrastive learning strategies obtain robust feature representation under quality variation. (3) A Separate Quality Network (SQN) is designed to learn discriminative features independent of image quality. Finally, a large number of experiments verify the quality of the SuHiFiMask dataset and the superiority of the proposed CQIL.
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In recent years, arbitrary image style transfer has attracted more and more attention. Given a pair of content and style images, a stylized one is hoped that retains the content from the former while catching style patterns from the latter. However, it is difficult to simultaneously keep well the trade-off between the content details and the style features. To stylize the image with sufficient style patterns, the content details may be damaged and sometimes the objects of images can not be distinguished clearly. For this reason, we present a new transformer-based method named STT for image style transfer and an edge loss which can enhance the content details apparently to avoid generating blurred results for excessive rendering on style features. Qualitative and quantitative experiments demonstrate that STT achieves comparable performance to state-of-the-art image style transfer methods while alleviating the content leak problem.
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Domain adaptation methods reduce domain shift typically by learning domain-invariant features. Most existing methods are built on distribution matching, e.g., adversarial domain adaptation, which tends to corrupt feature discriminability. In this paper, we propose Discriminative Radial Domain Adaptation (DRDR) which bridges source and target domains via a shared radial structure. It's motivated by the observation that as the model is trained to be progressively discriminative, features of different categories expand outwards in different directions, forming a radial structure. We show that transferring such an inherently discriminative structure would enable to enhance feature transferability and discriminability simultaneously. Specifically, we represent each domain with a global anchor and each category a local anchor to form a radial structure and reduce domain shift via structure matching. It consists of two parts, namely isometric transformation to align the structure globally and local refinement to match each category. To enhance the discriminability of the structure, we further encourage samples to cluster close to the corresponding local anchors based on optimal-transport assignment. Extensively experimenting on multiple benchmarks, our method is shown to consistently outperforms state-of-the-art approaches on varied tasks, including the typical unsupervised domain adaptation, multi-source domain adaptation, domain-agnostic learning, and domain generalization.
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This paper proposes a novel self-supervised based Cut-and-Paste GAN to perform foreground object segmentation and generate realistic composite images without manual annotations. We accomplish this goal by a simple yet effective self-supervised approach coupled with the U-Net based discriminator. The proposed method extends the ability of the standard discriminators to learn not only the global data representations via classification (real/fake) but also learn semantic and structural information through pseudo labels created using the self-supervised task. The proposed method empowers the generator to create meaningful masks by forcing it to learn informative per-pixel as well as global image feedback from the discriminator. Our experiments demonstrate that our proposed method significantly outperforms the state-of-the-art methods on the standard benchmark datasets.
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