Medical image segmentation methods typically rely on numerous dense annotated images for model training, which are notoriously expensive and time-consuming to collect. To alleviate this burden, weakly supervised techniques have been exploited to train segmentation models with less expensive annotations. In this paper, we propose a novel point-supervised contrastive variance method (PSCV) for medical image semantic segmentation, which only requires one pixel-point from each organ category to be annotated. The proposed method trains the base segmentation network by using a novel contrastive variance (CV) loss to exploit the unlabeled pixels and a partial cross-entropy loss on the labeled pixels. The CV loss function is designed to exploit the statistical spatial distribution properties of organs in medical images and their variance distribution map representations to enforce discriminative predictions over the unlabeled pixels. Experimental results on two standard medical image datasets demonstrate that the proposed method outperforms the state-of-the-art weakly supervised methods on point-supervised medical image semantic segmentation tasks.
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For saving cost, many deep neural networks (DNNs) are trained on third-party datasets downloaded from internet, which enables attacker to implant backdoor into DNNs. In 2D domain, inherent structures of different image formats are similar. Hence, backdoor attack designed for one image format will suite for others. However, when it comes to 3D world, there is a huge disparity among different 3D data structures. As a result, backdoor pattern designed for one certain 3D data structure will be disable for other data structures of the same 3D scene. Therefore, this paper designs a uniform backdoor pattern: NRBdoor (Noisy Rotation Backdoor) which is able to adapt for heterogeneous 3D data structures. Specifically, we start from the unit rotation and then search for the optimal pattern by noise generation and selection process. The proposed NRBdoor is natural and imperceptible, since rotation is a common operation which usually contains noise due to both the miss match between a pair of points and the sensor calibration error for real-world 3D scene. Extensive experiments on 3D mesh and point cloud show that the proposed NRBdoor achieves state-of-the-art performance, with negligible shape variation.
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Change detection (CD) is to decouple object changes (i.e., object missing or appearing) from background changes (i.e., environment variations) like light and season variations in two images captured in the same scene over a long time span, presenting critical applications in disaster management, urban development, etc. In particular, the endless patterns of background changes require detectors to have a high generalization against unseen environment variations, making this task significantly challenging. Recent deep learning-based methods develop novel network architectures or optimization strategies with paired-training examples, which do not handle the generalization issue explicitly and require huge manual pixel-level annotation efforts. In this work, for the first attempt in the CD community, we study the generalization issue of CD from the perspective of data augmentation and develop a novel weakly supervised training algorithm that only needs image-level labels. Different from general augmentation techniques for classification, we propose the background-mixed augmentation that is specifically designed for change detection by augmenting examples under the guidance of a set of background-changing images and letting deep CD models see diverse environment variations. Moreover, we propose the augmented & real data consistency loss that encourages the generalization increase significantly. Our method as a general framework can enhance a wide range of existing deep learning-based detectors. We conduct extensive experiments in two public datasets and enhance four state-of-the-art methods, demonstrating the advantages of our method. We release the code at https://github.com/tsingqguo/bgmix.
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The processing and recognition of geoscience images have wide applications. Most of existing researches focus on understanding the high-quality geoscience images by assuming that all the images are clear. However, in many real-world cases, the geoscience images might contain occlusions during the image acquisition. This problem actually implies the image inpainting problem in computer vision and multimedia. To the best of our knowledge, all the existing image inpainting algorithms learn to repair the occluded regions for a better visualization quality, they are excellent for natural images but not good enough for geoscience images by ignoring the geoscience related tasks. This paper aims to repair the occluded regions for a better geoscience task performance with the advanced visualization quality simultaneously, without changing the current deployed deep learning based geoscience models. Because of the complex context of geoscience images, we propose a coarse-to-fine encoder-decoder network with coarse-to-fine adversarial context discriminators to reconstruct the occluded image regions. Due to the limited data of geoscience images, we use a MaskMix based data augmentation method to exploit more information from limited geoscience image data. The experimental results on three public geoscience datasets for remote sensing scene recognition, cross-view geolocation and semantic segmentation tasks respectively show the effectiveness and accuracy of the proposed method.
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网络体系结构搜索(NAS),尤其是可区分的体系结构搜索(DARTS)方法,已经显示出在特定感兴趣的特定数据集中学习出色的模型体系结构的强大力量。与使用固定的数据集相反,在这项工作中,我们关注NAS的不同但重要的方案:如何完善部署的网络模型体系结构,以增强其鲁棒性,并通过一些收集和错误分类的示例的指导来增强其鲁棒性,这些示例被某些降低了现实世界中的未知损坏具有特定的模式(例如噪声,模糊等)。为此,我们首先进行了一项实证研究,以验证模型体系结构绝对与腐败模式有关。令人惊讶的是,通过仅添加一些损坏和错误分类的示例(例如,$ 10^3 $示例)到清洁培训数据集(例如$ 5.0 \ times 10^4 $示例)中,我们可以完善模型体系结构并显着增强鲁棒性。为了使其更加实用,应仔细研究关键问题,即如何为有效的NAS指导选择适当的失败示例。然后,我们提出了一个新颖的核心失效指导飞镖,该飞镖嵌入了K-Center-Greedy算法的飞镖,以选择合适的损坏故障示例以完善模型体系结构。我们使用我们的方法在清洁和15个腐败上使用飞镖精制的DNN,并在四个特定的现实世界腐败的指导下进行了指导。与最先进的NAS以及基于数据启发的增强方法相比,我们的最终方法可以在损坏的数据集和原始清洁数据集上获得更高的精度。在某些腐败模式上,我们可以达到超过45%的绝对准确性提高。
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Change detection (CD) aims to detect change regions within an image pair captured at different times, playing a significant role in diverse real-world applications. Nevertheless, most of the existing works focus on designing advanced network architectures to map the feature difference to the final change map while ignoring the influence of the quality of the feature difference. In this paper, we study the CD from a different perspective, i.e., how to optimize the feature difference to highlight changes and suppress unchanged regions, and propose a novel module denoted as iterative difference-enhanced transformers (IDET). IDET contains three transformers: two transformers for extracting the long-range information of the two images and one transformer for enhancing the feature difference. In contrast to the previous transformers, the third transformer takes the outputs of the first two transformers to guide the enhancement of the feature difference iteratively. To achieve more effective refinement, we further propose the multi-scale IDET-based change detection that uses multi-scale representations of the images for multiple feature difference refinements and proposes a coarse-to-fine fusion strategy to combine all refinements. Our final CD method outperforms seven state-of-the-art methods on six large-scale datasets under diverse application scenarios, which demonstrates the importance of feature difference enhancements and the effectiveness of IDET.
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预测中小型企业(SME)的破产风险(SME)是金融机构在做出贷款时的重要一步。但是,金融和AI研究领域的现有研究倾向于仅考虑企业内风险或传染性风险,而忽略了它们的相互作用和组合效应。这项研究首次考虑了在破产预测中的风险及其共同影响。具体而言,我们首先根据其风险内学习的统计学意义企业风险指标提出了企业内风险编码器。然后,我们根据企业关系信息从企业知识图中提出了一个企业传染风险编码器,以进行其传染风险嵌入。特别是,传染风险编码器既包括新提出的高图神经网络和异质图神经网络,这些神经网络可以在两个不同方面建模传播风险,即基于超系统的常见风险因素和直接扩散的风险。为了评估该模型,我们收集了SME上的现实世界多源数据数据,并构建了一个名为SMESD的新型基准数据集。我们提供对数据集的开放访问权限,该数据集有望进一步促进财务风险分析的研究。针对十二个最先进的基线的SMESD实验证明了拟议模型对破产预测的有效性。
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弱监督学习可以帮助本地特征方法来克服以密集标记的对应关系获取大规模数据集的障碍。然而,由于弱监管无法区分检测和描述步骤造成的损失,因此直接在联合描述 - 然后检测管道内进行弱监督的学习,其性能受到限制。在本文中,我们提出了一种针对弱监督当地特征学习量身定制的解耦描述的管道。在我们的管道内,检测步骤与描述步骤分离并推迟直到学习判别和鲁棒描述符。此外,我们介绍了一条线到窗口搜索策略,以明确地使用相机姿势信息以获得更好的描述符学习。广泛的实验表明,我们的方法,即POSFEAT(相机姿势监督特征),以前完全和弱监督的方法优异,在各种下游任务上实现了最先进的性能。
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派生是一个重要而基本的计算机视觉任务,旨在消除在下雨天捕获的图像或视频中的雨条纹和累积。现有的派威方法通常会使雨水模型的启发式假设,这迫使它们采用复杂的优化或迭代细化以获得高回收质量。然而,这导致耗时的方法,并影响解决从假设偏离的雨水模式的有效性。在本文中,我们通过在没有复杂的雨水模型假设的情况下,通过在没有复杂的雨水模型假设的情况下制定污染作为预测滤波问题的简单而有效的污染方法。具体地,我们识别通过深网络自适应地预测适当的核的空间变型预测滤波(SPFILT以过滤不同的各个像素。由于滤波可以通过加速卷积来实现,因此我们的方法可以显着效率。我们进一步提出了eFderain +,其中包含三个主要贡献来解决残留的雨迹,多尺度和多样化的雨水模式而不会损害效率。首先,我们提出了不确定感知的级联预测滤波(UC-PFILT),其可以通过预测的内核来识别重建清洁像素的困难,并有效地移除残留的雨水迹线。其次,我们设计重量共享多尺度扩张过滤(WS-MS-DFILT),以处理多尺度雨条纹,而不会损害效率。第三,消除各种雨水模式的差距,我们提出了一种新颖的数据增强方法(即Rainmix)来培养我们的深层模型。通过对不同变体的复杂分析的所有贡献相结合,我们的最终方法在恢复质量和速度方面优于四个单像辐照数据集和一个视频派威数据集的基线方法。
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面部地标检测是具有许多重要应用的非常基本和重要的愿景任务。在实践中,面部地标检测可能受到大量自然降级的影响。最常见和最重要的降解之一是光源阻塞引起的阴影。虽然已经提出了许多先进的阴影去除方法来恢复近年来的图像质量,但它们对面部地标检测的影响并不具备很好的研究。例如,它仍然不清楚阴影去除是否可以增强面部地标检测的鲁棒性,以与不同的阴影模式。在这项工作中,为了第一次尝试,我们构建了一个新颖的基准,以将两个独立但相关任务联系起来(即阴影去除和面部地标检测)。特别是,所提出的基准覆盖具有不同强度,尺寸,形状和位置的不同面孔阴影。此外,对于对面部地标检测的挤出硬影模式,我们提出了一种新的方法(即,普发的阴影攻击),这使我们能够构建基准的具有挑战性的综合分析。通过构造的基准,我们对三个最先进的阴影清除方法和三个地标检测器进行了广泛的分析。这项工作的观察激励我们设计一种新颖的检测感知阴影拆除框架,使暗影去除以实现更高的恢复质量并增强部署的面部地标检测器的阴影稳健性。
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