Weakly-supervised learning (WSL) has been proposed to alleviate the conflict between data annotation cost and model performance through employing sparsely-grained (i.e., point-, box-, scribble-wise) supervision and has shown promising performance, particularly in the image segmentation field. However, it is still a very challenging problem due to the limited supervision, especially when only a small number of labeled samples are available. Additionally, almost all existing WSL segmentation methods are designed for star-convex structures which are very different from curvilinear structures such as vessels and nerves. In this paper, we propose a novel sparsely annotated segmentation framework for curvilinear structures, named YoloCurvSeg, based on image synthesis. A background generator delivers image backgrounds that closely match real distributions through inpainting dilated skeletons. The extracted backgrounds are then combined with randomly emulated curves generated by a Space Colonization Algorithm-based foreground generator and through a multilayer patch-wise contrastive learning synthesizer. In this way, a synthetic dataset with both images and curve segmentation labels is obtained, at the cost of only one or a few noisy skeleton annotations. Finally, a segmenter is trained with the generated dataset and possibly an unlabeled dataset. The proposed YoloCurvSeg is evaluated on four publicly available datasets (OCTA500, CORN, DRIVE and CHASEDB1) and the results show that YoloCurvSeg outperforms state-of-the-art WSL segmentation methods by large margins. With only one noisy skeleton annotation (respectively 0.14%, 0.02%, 1.4%, and 0.65% of the full annotation), YoloCurvSeg achieves more than 97% of the fully-supervised performance on each dataset. Code and datasets will be released at https://github.com/llmir/YoloCurvSeg.
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Talking face generation aims at generating photo-realistic video portraits of a target person driven by input audio. Due to its nature of one-to-many mapping from the input audio to the output video (e.g., one speech content may have multiple feasible visual appearances), learning a deterministic mapping like previous works brings ambiguity during training, and thus causes inferior visual results. Although this one-to-many mapping could be alleviated in part by a two-stage framework (i.e., an audio-to-expression model followed by a neural-rendering model), it is still insufficient since the prediction is produced without enough information (e.g., emotions, wrinkles, etc.). In this paper, we propose MemFace to complement the missing information with an implicit memory and an explicit memory that follow the sense of the two stages respectively. More specifically, the implicit memory is employed in the audio-to-expression model to capture high-level semantics in the audio-expression shared space, while the explicit memory is employed in the neural-rendering model to help synthesize pixel-level details. Our experimental results show that our proposed MemFace surpasses all the state-of-the-art results across multiple scenarios consistently and significantly.
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Stochastic gradients closely relate to both optimization and generalization of deep neural networks (DNNs). Some works attempted to explain the success of stochastic optimization for deep learning by the arguably heavy-tail properties of gradient noise, while other works presented theoretical and empirical evidence against the heavy-tail hypothesis on gradient noise. Unfortunately, formal statistical tests for analyzing the structure and heavy tails of stochastic gradients in deep learning are still under-explored. In this paper, we mainly make two contributions. First, we conduct formal statistical tests on the distribution of stochastic gradients and gradient noise across both parameters and iterations. Our statistical tests reveal that dimension-wise gradients usually exhibit power-law heavy tails, while iteration-wise gradients and stochastic gradient noise caused by minibatch training usually do not exhibit power-law heavy tails. Second, we further discover that the covariance spectra of stochastic gradients have the power-law structures in deep learning. While previous papers believed that the anisotropic structure of stochastic gradients matters to deep learning, they did not expect the gradient covariance can have such an elegant mathematical structure. Our work challenges the existing belief and provides novel insights on the structure of stochastic gradients in deep learning.
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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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Artificial Intelligence (AI) is having a tremendous impact across most areas of science. Applications of AI in healthcare have the potential to improve our ability to detect, diagnose, prognose, and intervene on human disease. For AI models to be used clinically, they need to be made safe, reproducible and robust, and the underlying software framework must be aware of the particularities (e.g. geometry, physiology, physics) of medical data being processed. This work introduces MONAI, a freely available, community-supported, and consortium-led PyTorch-based framework for deep learning in healthcare. MONAI extends PyTorch to support medical data, with a particular focus on imaging, and provide purpose-specific AI model architectures, transformations and utilities that streamline the development and deployment of medical AI models. MONAI follows best practices for software-development, providing an easy-to-use, robust, well-documented, and well-tested software framework. MONAI preserves the simple, additive, and compositional approach of its underlying PyTorch libraries. MONAI is being used by and receiving contributions from research, clinical and industrial teams from around the world, who are pursuing applications spanning nearly every aspect of healthcare.
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Pixel-wise prediction with deep neural network has become an effective paradigm for salient object detection (SOD) and achieved remarkable performance. However, very few SOD models are robust against adversarial attacks which are visually imperceptible for human visual attention. The previous work robust saliency (ROSA) shuffles the pre-segmented superpixels and then refines the coarse saliency map by the densely connected conditional random field (CRF). Different from ROSA that relies on various pre- and post-processings, this paper proposes a light-weight Learnable Noise (LeNo) to defend adversarial attacks for SOD models. LeNo preserves accuracy of SOD models on both adversarial and clean images, as well as inference speed. In general, LeNo consists of a simple shallow noise and noise estimation that embedded in the encoder and decoder of arbitrary SOD networks respectively. Inspired by the center prior of human visual attention mechanism, we initialize the shallow noise with a cross-shaped gaussian distribution for better defense against adversarial attacks. Instead of adding additional network components for post-processing, the proposed noise estimation modifies only one channel of the decoder. With the deeply-supervised noise-decoupled training on state-of-the-art RGB and RGB-D SOD networks, LeNo outperforms previous works not only on adversarial images but also on clean images, which contributes stronger robustness for SOD. Our code is available at https://github.com/ssecv/LeNo.
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现有检测方法通常使用参数化边界框(Bbox)进行建模和检测(水平)对象,并将其他旋转角参数用于旋转对象。我们认为,这种机制在建立有效的旋转检测回归损失方面具有根本的局限性,尤其是对于高精度检测而言,高精度检测(例如0.75)。取而代之的是,我们建议将旋转的对象建模为高斯分布。一个直接的优势是,我们关于两个高斯人之间距离的新回归损失,例如kullback-leibler Divergence(KLD)可以很好地对齐实际检测性能度量标准,这在现有方法中无法很好地解决。此外,两个瓶颈,即边界不连续性和正方形的问题也消失了。我们还提出了一种有效的基于高斯度量的标签分配策略,以进一步提高性能。有趣的是,通过在基于高斯的KLD损失下分析Bbox参数的梯度,我们表明这些参数通过可解释的物理意义进行了动态更新,这有助于解释我们方法的有效性,尤其是对于高精度检测。我们使用量身定制的算法设计将方法从2-D扩展到3-D,以处理标题估计,并在十二个公共数据集(2-D/3-D,空中/文本/脸部图像)上进行了各种基本检测器的实验结果。展示其优越性。
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多文件科学摘要(MDSS)旨在为与主题相关的科学论文群生成连贯和简洁的摘要。此任务需要精确理解纸张内容以及对交叉纸关系的准确建模。知识图为文档传达了紧凑且可解释的结构化信息,这使其非常适合内容建模和关系建模。在本文中,我们提出了KGSUM,这是一个MDSS模型,以编码和解码过程中的知识图为中心。具体而言,在编码过程中,提出了两个基于图的模块,以将知识图信息纳入纸张编码,而在解码过程中,我们通过以描述性句子的形式首先生成摘要的知识图,提出了一个两阶段解码器。 ,然后生成最终摘要。经验结果表明,所提出的体系结构对多XSCIENCE数据集的基准进行了实质性改进。
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尽管以前基于图的多视图聚类算法已经取得了重大进展,但其中大多数仍面临三个限制。首先,他们经常遭受高计算复杂性的困扰,这限制了他们在大规模场景中的应用。其次,他们通常在单视图级别或视图传感级别上执行图形学习,但经常忽略单视图和共识图的联合学习的可能性。第三,其中许多人依靠$ k $ - 表示光谱嵌入的离散化,这些嵌入缺乏直接使用离散群集结构直接学习图形的能力。鉴于此,本文通过统一和离散的两部分图(UDBGL)提出了一种有效的多视图聚类方法。具体而言,基于锚的子空间学习被合并为从多个视图中学习特定的二分化图,并利用双方图融合来学习具有自适应重量学习的视图 - 谐镜双分歧图。此外,施加Laplacian等级约束以确保融合的两分图具有离散的群集结构(具有特定数量的连接组件)。通过同时制定特定视图的两分图学习,视图 - 共表的两分图学习以及离散的群集结构学习到统一的目标函数中,然后设计有效的最小化算法来解决此优化问题,并直接实现离散的聚类解决方案解决方案解决方案解决方案解决方案。不需要其他分区,这特别是数据大小的线性时间复杂性。各种多视图数据集的实验证明了我们的UDBGL方法的鲁棒性和效率。
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通过恢复(实体瘤的响应评估标准)自动测量病变/肿瘤大小,直径和分割对于计算机辅助诊断很重要。尽管近年来已经研究了它,但仍有空间可以提高其准确性和鲁棒性,例如(1)通过合并丰富的上下文信息来增强功能,同时保持高空间分辨率,(2)涉及新任务和损失以进行关节优化。为了实现这一目标,本文提出了一个基于变压器的网络(Meaformer,测量变压器),用于病变恢复直径预测和分割(LRDPS)。它被配制为三个相关和互补任务:病变分割,热图预测和关键点回归。据我们所知,这是首次使用按键重点回归进行恢复直径预测。 MeaeFormer可以通过使用变压器来捕获其远程依赖性来增强高分辨率功能。引入了两个一致性损失,以明确建立这些任务之间的关系,以更好地优化。实验表明,MeAformer实现了LRDP在大规模深层数据集上的最新性能,并在纵向研究中产生了两个下游诊所的任务,即3D病变细分和恢复评估。
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