蒙面图像建模(MIM)在各种视觉任务上取得了令人鼓舞的结果。但是,学到的表示形式的有限可区分性表现出来,使一个更强大的视力学习者还有很多值得一试。为了实现这一目标,我们提出了对比度蒙面的自动编码器(CMAE),这是一种新的自我监督的预训练方法,用于学习更全面和有能力的视觉表示。通过详细统一的对比度学习(CL)和掩盖图像模型(MIM),CMAE利用了它们各自的优势,并以强大的实例可辨别性和局部的可感知来学习表示形式。具体而言,CMAE由两个分支组成,其中在线分支是不对称的编码器编码器,而目标分支是动量更新的编码器。在培训期间,在线编码器从蒙面图像的潜在表示中重建了原始图像,以学习整体特征。馈送完整图像的目标编码器通过其在线学习通过对比度学习增强了功能可区分性。为了使CL与MIM兼容,CMAE引入了两个新组件,即用于生成合理的正视图和特征解码器的像素移位,以补充对比度对的特征。多亏了这些新颖的设计,CMAE可以有效地提高了MIM对应物的表示质量和转移性能。 CMAE在图像分类,语义分割和对象检测的高度竞争基准上实现了最先进的性能。值得注意的是,CMAE-BASE在Imagenet上获得了$ 85.3 \%$ $ TOP-1的准确性和$ 52.5 \%$ MIOU的ADE20K,分别超过了$ 0.7 \%\%$ $和$ 1.8 \%$ $。代码将公开可用。
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最近的研究表明,风格老年提供了对图像合成和编辑的下游任务的有希望的现有模型。然而,由于样式盖的潜在代码被设计为控制全球样式,因此很难实现对合成图像的细粒度控制。我们提出了SemanticStylegan,其中发电机训练以分别培训局部语义部件,并以组成方式合成图像。不同局部部件的结构和纹理由相应的潜在码控制。实验结果表明,我们的模型在不同空间区域之间提供了强烈的解剖。当与为样式器设计的编辑方法结合使用时,它可以实现更细粒度的控制,以编辑合成或真实图像。该模型也可以通过传输学习扩展到其他域。因此,作为具有内置解剖学的通用先前模型,它可以促进基于GaN的应用的发展并实现更多潜在的下游任务。
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视频突出对象检测旨在在视频中找到最具视觉上的对象。为了探索时间依赖性,现有方法通常是恢复性的神经网络或光学流量。然而,这些方法需要高计算成本,并且往往会随着时间的推移积累不准确性。在本文中,我们提出了一种带有注意模块的网络,以学习视频突出物体检测的对比特征,而没有高计算时间建模技术。我们开发了非本地自我关注方案,以捕获视频帧中的全局信息。共注意配方用于结合低级和高级功能。我们进一步应用了对比学学习以改善来自相同视频的前景区域对的特征表示,并将前景 - 背景区域对被推除在潜在的空间中。帧内对比损失有助于将前景和背景特征分开,并且帧间的对比损失提高了时间的稠度。我们对多个基准数据集进行广泛的实验,用于视频突出对象检测和无监督的视频对象分割,并表明所提出的方法需要较少的计算,并且对最先进的方法进行有利地执行。
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在本文中,我们探索了开放式剪影到照片转换,旨在将备用素描与其类标签中的徒手素描合成,即使培训数据中缺少该类的草图。由于缺乏训练监督和写法草图和照片域之间的大几何扭曲,这是挑战性的。要从照片中综合缺少的手绘草图,我们提出了一个框架,共同学习素描到照片和照片到素描生成。然而,由于合成草图和真实的域间隙,从假草图训练的发电机可能导致缺失类的草图时导致不满意的结果。为了缓解这个问题,我们进一步提出了一种简单但有效的开放式采样和优化策略,以“愚弄”将发电机视为真实的草图。我们的方法利用了域名数据的学习素描到照片和照片到草图映射,并将其概括为开放式域类。我们在涂鸦和Sketchycoco数据集上验证我们的方法。与最近的竞争方法相比,我们的方法显示令人印象深刻的成果,在综合逼真的颜色,纹理和维护各类开放式域草图的几何组合物方面。我们的代码可在https://github.com/mukosame/aoda获得
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Deep learning-based methods have achieved remarkable success in image restoration and enhancement, but are they still competitive when there is a lack of paired training data? As one such example, this paper explores the low-light image enhancement problem, where in practice it is extremely challenging to simultaneously take a low-light and a normal-light photo of the same visual scene. We propose a highly effective unsupervised generative adversarial network, dubbed Enlight-enGAN, that can be trained without low/normal-light image pairs, yet proves to generalize very well on various real-world test images. Instead of supervising the learning using ground truth data, we propose to regularize the unpaired training using the information extracted from the input itself, and benchmark a series of innovations for the low-light image enhancement problem, including a global-local discriminator structure, a selfregularized perceptual loss fusion, and the attention mechanism. Through extensive experiments, our proposed approach outperforms recent methods under a variety of metrics in terms of visual quality and subjective user study. Thanks to the great flexibility brought by unpaired training, EnlightenGAN is demonstrated to be easily adaptable to enhancing real-world images from various domains. Our codes and pre-trained models are available at: https://github.com/VITA-Group/EnlightenGAN.
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In this paper, we address referring expression comprehension: localizing an image region described by a natural language expression. While most recent work treats expressions as a single unit, we propose to decompose them into three modular components related to subject appearance, location, and relationship to other objects. This allows us to flexibly adapt to expressions containing different types of information in an end-to-end framework. In our model, which we call the Modular Attention Network (MAttNet), two types of attention are utilized: languagebased attention that learns the module weights as well as the word/phrase attention that each module should focus on; and visual attention that allows the subject and relationship modules to focus on relevant image components. Module weights combine scores from all three modules dynamically to output an overall score. Experiments show that MAttNet outperforms previous state-of-the-art methods by a large margin on both bounding-box-level and pixel-level comprehension tasks. Demo 1 and code 2 are provided.
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Figure 1: Example inpainting results of our method on images of natural scene, face and texture. Missing regions are shown in white. In each pair, the left is input image and right is the direct output of our trained generative neural networks without any post-processing.
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We aim to model the top-down attention of a Convolutional Neural Network (CNN) classifier for generating task-specific attention maps. Inspired by a top-down human visual attention model, we propose a new backpropagation scheme, called Excitation Backprop, to pass along top-down signals downwards in the network hierarchy via a probabilistic Winner-Take-All process. Furthermore, we introduce the concept of contrastive attention to make the top-down attention maps more discriminative. In experiments, we demonstrate the accuracy and generalizability of our method in weakly supervised localization tasks on the MS COCO, PASCAL VOC07 and ImageNet datasets. The usefulness of our method is further validated in the text-to-region association task. On the Flickr30k Entities dataset, we achieve promising performance in phrase localization by leveraging the top-down attention of a CNN model that has been trained on weakly labeled web images.
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Dataset distillation has emerged as a prominent technique to improve data efficiency when training machine learning models. It encapsulates the knowledge from a large dataset into a smaller synthetic dataset. A model trained on this smaller distilled dataset can attain comparable performance to a model trained on the original training dataset. However, the existing dataset distillation techniques mainly aim at achieving the best trade-off between resource usage efficiency and model utility. The security risks stemming from them have not been explored. This study performs the first backdoor attack against the models trained on the data distilled by dataset distillation models in the image domain. Concretely, we inject triggers into the synthetic data during the distillation procedure rather than during the model training stage, where all previous attacks are performed. We propose two types of backdoor attacks, namely NAIVEATTACK and DOORPING. NAIVEATTACK simply adds triggers to the raw data at the initial distillation phase, while DOORPING iteratively updates the triggers during the entire distillation procedure. We conduct extensive evaluations on multiple datasets, architectures, and dataset distillation techniques. Empirical evaluation shows that NAIVEATTACK achieves decent attack success rate (ASR) scores in some cases, while DOORPING reaches higher ASR scores (close to 1.0) in all cases. Furthermore, we conduct a comprehensive ablation study to analyze the factors that may affect the attack performance. Finally, we evaluate multiple defense mechanisms against our backdoor attacks and show that our attacks can practically circumvent these defense mechanisms.
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Few Shot Instance Segmentation (FSIS) requires models to detect and segment novel classes with limited several support examples. In this work, we explore a simple yet unified solution for FSIS as well as its incremental variants, and introduce a new framework named Reference Twice (RefT) to fully explore the relationship between support/query features based on a Transformer-like framework. Our key insights are two folds: Firstly, with the aid of support masks, we can generate dynamic class centers more appropriately to re-weight query features. Secondly, we find that support object queries have already encoded key factors after base training. In this way, the query features can be enhanced twice from two aspects, i.e., feature-level and instance-level. In particular, we firstly design a mask-based dynamic weighting module to enhance support features and then propose to link object queries for better calibration via cross-attention. After the above steps, the novel classes can be improved significantly over our strong baseline. Additionally, our new framework can be easily extended to incremental FSIS with minor modification. When benchmarking results on the COCO dataset for FSIS, gFSIS, and iFSIS settings, our method achieves a competitive performance compared to existing approaches across different shots, e.g., we boost nAP by noticeable +8.2/+9.4 over the current state-of-the-art FSIS method for 10/30-shot. We further demonstrate the superiority of our approach on Few Shot Object Detection. Code and model will be available.
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