Video Super-Resolution (VSR) aims to restore high-resolution (HR) videos from low-resolution (LR) videos. Existing VSR techniques usually recover HR frames by extracting pertinent textures from nearby frames with known degradation processes. Despite significant progress, grand challenges are remained to effectively extract and transmit high-quality textures from high-degraded low-quality sequences, such as blur, additive noises, and compression artifacts. In this work, a novel Frequency-Transformer (FTVSR) is proposed for handling low-quality videos that carry out self-attention in a combined space-time-frequency domain. First, video frames are split into patches and each patch is transformed into spectral maps in which each channel represents a frequency band. It permits a fine-grained self-attention on each frequency band, so that real visual texture can be distinguished from artifacts. Second, a novel dual frequency attention (DFA) mechanism is proposed to capture the global frequency relations and local frequency relations, which can handle different complicated degradation processes in real-world scenarios. Third, we explore different self-attention schemes for video processing in the frequency domain and discover that a ``divided attention'' which conducts a joint space-frequency attention before applying temporal-frequency attention, leads to the best video enhancement quality. Extensive experiments on three widely-used VSR datasets show that FTVSR outperforms state-of-the-art methods on different low-quality videos with clear visual margins. Code and pre-trained models are available at https://github.com/researchmm/FTVSR.
translated by 谷歌翻译
Vision Transformers have shown great promise recently for many vision tasks due to the insightful architecture design and attention mechanism. By revisiting the self-attention responses in Transformers, we empirically observe two interesting issues. First, Vision Transformers present a queryirrelevant behavior at deep layers, where the attention maps exhibit nearly consistent contexts in global scope, regardless of the query patch position (also head-irrelevant). Second, the attention maps are intrinsically sparse, few tokens dominate the attention weights; introducing the knowledge from ConvNets would largely smooth the attention and enhance the performance. Motivated by above observations, we generalize self-attention formulation to abstract a queryirrelevant global context directly and further integrate the global context into convolutions. The resulting model, a Fully Convolutional Vision Transformer (i.e., FCViT), purely consists of convolutional layers and firmly inherits the merits of both attention mechanism and convolutions, including dynamic property, weight sharing, and short- and long-range feature modeling, etc. Experimental results demonstrate the effectiveness of FCViT. With less than 14M parameters, our FCViT-S12 outperforms related work ResT-Lite by 3.7% top1 accuracy on ImageNet-1K. When scaling FCViT to larger models, we still perform better than previous state-of-the-art ConvNeXt with even fewer parameters. FCViT-based models also demonstrate promising transferability to downstream tasks, like object detection, instance segmentation, and semantic segmentation. Codes and models are made available at: https://github.com/ma-xu/FCViT.
translated by 谷歌翻译
The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
translated by 谷歌翻译
当与分支和界限结合使用时,结合的传播方法是正式验证深神经网络(例如正确性,鲁棒性和安全性)的最有效方法之一。但是,现有作品无法处理在传统求解器中广泛接受的切割平面限制的一般形式,这对于通过凸出凸松弛的加强验证者至关重要。在本文中,我们概括了结合的传播程序,以允许添加任意切割平面的约束,包括涉及放宽整数变量的限制,这些变量未出现在现有的结合传播公式中。我们的广义结合传播方法GCP-crown为应用一般切割平面方法}开辟了一个机会进行神经网络验证,同时受益于结合传播方法的效率和GPU加速。作为案例研究,我们研究了由现成的混合整数编程(MIP)求解器生成的切割平面的使用。我们发现,MIP求解器可以生成高质量的切割平面,以使用我们的新配方来增强基于界限的验证者。由于以分支为重点的绑定传播程序和切削平面的MIP求解器可以使用不同类型的硬件(GPU和CPU)并行运行,因此它们的组合可以迅速探索大量具有强切割平面的分支,从而导致强大的分支验证性能。实验表明,与VNN-Comp 2021中最佳工具相比,我们的方法是第一个可以完全求解椭圆形的基准并验证椭圆21基准的两倍的验证者,并且在oval21基准测试中的最佳工具也明显超过了最先进的验证器。广泛的基准。 GCP-Crown是$ \ alpha $,$ \ beta $ -Crown验证者,VNN-COMP 2022获奖者的一部分。代码可在http://papercode.cc/gcp-crown上获得
translated by 谷歌翻译
磁共振图像(MRI)中的脑肿瘤分割(BTS)对于脑肿瘤诊断,癌症管理和研究目的至关重要。随着十年小型挑战的巨大成功以及CNN和Transformer算法的进步,已经提出了许多出色的BTS模型来解决BTS在不同技术方面的困难。但是,现有研究几乎没有考虑如何以合理的方式融合多模式图像。在本文中,我们利用了放射科医生如何从多种MRI模态诊断脑肿瘤的临床知识,并提出了一种称为CKD-TRANSBTS的临床知识驱动的脑肿瘤分割模型。我们没有直接串联所有模式,而是通过根据MRI的成像原理将输入方式分为两组来重新组织输入方式。具有拟议模态相关的跨意义块(MCCA)的双支支混合式编码器旨在提取多模式图像特征。所提出的模型以局部特征表示能力的能力来继承来自变压器和CNN的强度,以提供精确的病变边界和3D体积图像的远程特征提取。为了弥合变压器和CNN功能之间的间隙,我们提出了解码器中的反式和CNN功能校准块(TCFC)。我们将提出的模型与五个基于CNN的模型和六个基于Transformer的模型在Brats 2021挑战数据集上进行了比较。广泛的实验表明,与所有竞争对手相比,所提出的模型可实现最先进的脑肿瘤分割性能。
translated by 谷歌翻译
由于其高识别精度,包括移动设备的面部解锁,社区访问控制系统和城市监视,因此在许多领域都使用了面部识别技术。由于非常深的网络结构可以保证当前的高精度,因此通常需要将面部图像传输到具有高计算能力以进行推理的第三方服务器。但是,面部图像在视觉上揭示了用户的身份信息。在此过程中,不受信任的服务提供商和恶意用户都可以显着增加个人隐私漏洞的风险。当前的隐私识别方法通常伴随着许多副作用,例如推理时间的显着增加或明显的识别准确性下降。本文提出了使用频域中使用差异隐私的保护隐私面部识别方法。由于利用了差异隐私,它在理论上提供了隐私的保证。同时,准确性的丧失非常小。该方法首先将原始图像转换为频域,并删除称为DC的直接组件。然后,可以根据差异隐私框架内的后端面部识别网络的丢失来学习隐私预算分配方法。最后,它为频域特征添加了相应的噪声。根据广泛的实验,我们的方法在几个经典的面部识别测试集中表现出色。
translated by 谷歌翻译
针对OGB图分类任务中的两个分子图数据集和一个蛋白质关联子图数据集,我们通过引入PAS(池架构搜索)设计一个图形神经网络框架,用于图形分类任务。同时,我们根据GNN拓扑设计方法F2GNN进行改进GNN培训。最后,在这三个数据集上实现了性能突破,这比具有固定聚合功能的其他方法要好得多。事实证明,NAS方法具有多个任务的高概括能力以及我们在处理图形属性预测任务方面的优势。
translated by 谷歌翻译
图形神经网络是一种强大的深度学习工具,用于建模图形结构化数据,在众多图形学习任务上表现出了出色的性能。为了解决深图学习中的数据噪声和数据稀缺性问题,最近有关图形数据的研究已加剧。但是,常规数据增强方法几乎无法处理具有多模式性的非欧几里得空间中定义的图形结构化数据。在这项调查中,我们正式提出了图数据扩展的问题,并进一步审查了代表性技术及其在不同深度学习问题中的应用。具体而言,我们首先提出了图形数据扩展技术的分类法,然后通过根据增强信息方式对相关工作进行分类,从而提供结构化的审查。此外,我们总结了以数据为中心的深图学习中两个代表性问题中图数据扩展的应用:(1)可靠的图形学习,重点是增强输入图的实用性以及通过图数据增强的模型容量; (2)低资源图学习,其针对通过图数据扩大标记的训练数据量表的目标。对于每个问题,我们还提供层次结构问题分类法,并审查与图数据增强相关的现有文献。最后,我们指出了有希望的研究方向和未来研究的挑战。
translated by 谷歌翻译
双链DNA断裂(DSB)是一种DNA损伤的形式,可导致异常染色体重排。基于高吞吐量实验的最近技术具有明显的高成本和技术挑战。因此,我们设计了一种基于图形的神经网络的方法来预测DSB(GraphDSB),使用DNA序列特征和染色体结构信息。为了提高模型的表达能力,我们引入跳跃知识架构和几种有效的结构编码方法。结构信息对DSB预测的贡献是通过来自正常人体表皮角蛋白细胞(NHEK)和慢性髓性白血病细胞系(K562)的数据集的实验验证,并且消融研究进一步证明了所提出的设计部件的有效性GraphDSB框架。最后,我们使用GNNExplainer分析节点特征和拓扑到DSB预测的贡献,并证明了5-MER DNA序列特征和两种染色质相互作用模式的高贡献。
translated by 谷歌翻译
基于稀疏的代表的分类(SRC)通过将识别问题作为简单的线性回归问题铸造了很多关注。然而,SRC方法仍然仅限于每类别的足够标记的样本,不充分使用未标记的样本,以及表示的不稳定性。为了解决这些问题,提出了一种未标记的数据驱动的逆投影伪全空间表示的基于空间表示的分类模型,具有低级稀疏约束。所提出的模型旨在挖掘所有可用数据的隐藏语义信息和内在结构信息,这适用于少量标记的样本和标记样本与正面识别中的未标记样本问题之间的比例不平衡。引入了混合的高斯Seidel和Jacobian Admm算法来解决模型。分析了模型的收敛性,表示能力和稳定性。在三个公共数据集上的实验表明,所提出的LR-S-PFSRC模型达到稳定的结果,特别是对于样品的比例不平衡。
translated by 谷歌翻译