Exploring dense matching between the current frame and past frames for long-range context modeling, memory-based methods have demonstrated impressive results in video object segmentation (VOS) recently. Nevertheless, due to the lack of instance understanding ability, the above approaches are oftentimes brittle to large appearance variations or viewpoint changes resulted from the movement of objects and cameras. In this paper, we argue that instance understanding matters in VOS, and integrating it with memory-based matching can enjoy the synergy, which is intuitively sensible from the definition of VOS task, \ie, identifying and segmenting object instances within the video. Towards this goal, we present a two-branch network for VOS, where the query-based instance segmentation (IS) branch delves into the instance details of the current frame and the VOS branch performs spatial-temporal matching with the memory bank. We employ the well-learned object queries from IS branch to inject instance-specific information into the query key, with which the instance-augmented matching is further performed. In addition, we introduce a multi-path fusion block to effectively combine the memory readout with multi-scale features from the instance segmentation decoder, which incorporates high-resolution instance-aware features to produce final segmentation results. Our method achieves state-of-the-art performance on DAVIS 2016/2017 val (92.6% and 87.1%), DAVIS 2017 test-dev (82.8%), and YouTube-VOS 2018/2019 val (86.3% and 86.3%), outperforming alternative methods by clear margins.
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Recent breakthroughs in semi-supervised semantic segmentation have been developed through contrastive learning. In prevalent pixel-wise contrastive learning solutions, the model maps pixels to deterministic representations and regularizes them in the latent space. However, there exist inaccurate pseudo-labels which map the ambiguous representations of pixels to the wrong classes due to the limited cognitive ability of the model. In this paper, we define pixel-wise representations from a new perspective of probability theory and propose a Probabilistic Representation Contrastive Learning (PRCL) framework that improves representation quality by taking its probability into consideration. Through modelling the mapping from pixels to representations as the probability via multivariate Gaussian distributions, we can tune the contribution of the ambiguous representations to tolerate the risk of inaccurate pseudo-labels. Furthermore, we define prototypes in the form of distributions, which indicates the confidence of a class, while the point prototype cannot. Moreover, we propose to regularize the distribution variance to enhance the reliability of representations. Taking advantage of these benefits, high-quality feature representations can be derived in the latent space, thereby the performance of semantic segmentation can be further improved. We conduct sufficient experiment to evaluate PRCL on Pascal VOC and CityScapes to demonstrate its superiority. The code is available at https://github.com/Haoyu-Xie/PRCL.
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大型预估计模型(例如GPT-3)取得了显着的性能,在训练过程中暴露于大量数据上。类似地,将如此大型模型提炼成紧凑的模型以进行有效的部署,也需要大量(标记或未标记的)培训数据。在本文中,我们提出了培训高质量紧凑型模型的教师指导培训(TGT)框架,该模型利用了预验证的生成模型获得的知识,同时避免了大量数据的需求。 TGT利用了教师获得基础数据域的良好表示的事实,该事实通常对应于比输入空间要低得多的尺寸歧管。此外,我们可以使用老师通过采样或基于梯度的方法来更有效地探索输入空间。因此,使TGT对于有限的数据或长尾设置特别有吸引力。我们正式在我们的概括范围内正式捕获了所提出的数据域探索的好处。我们发现TGT可以提高几个图像分类基准以及一系列文本分类和检索任务的准确性。
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最近,与培训样本相比,具有越来越多的网络参数的过度参数深度网络主导了现代机器学习的性能。但是,当培训数据被损坏时,众所周知,过度参数化的网络往往会过度合适并且不会概括。在这项工作中,我们提出了一种有原则的方法,用于在分类任务中对过度参数的深层网络进行强有力的培训,其中一部分培训标签被损坏。主要想法还很简单:标签噪声与从干净的数据中学到的网络稀疏且不一致,因此我们对噪声进行建模并学会将其与数据分开。具体而言,我们通过另一个稀疏的过度参数术语对标签噪声进行建模,并利用隐式算法正规化来恢复和分离基础损坏。值得注意的是,当在实践中使用如此简单的方法培训时,我们证明了针对各种真实数据集上标签噪声的最新测试精度。此外,我们的实验结果通过理论在简化的线性模型上证实,表明在不连贯的条件下稀疏噪声和低级别数据之间的精确分离。这项工作打开了许多有趣的方向,可以使用稀疏的过度参数化和隐式正则化来改善过度参数化模型。
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这项工作试图提供一种合理的理论框架,旨在从数据压缩和歧视性代表的原则解释现代深度(卷积)网络。我们认为,对于高维多类数据,最佳线性判别表示最大化整个数据集之间的编码率差和所有子集的平均值。我们表明,用于优化速率降低目标的基本迭代梯度上升方案自然地导致了一个名为Redunet的多层深网络,其共享现代深度网络的共同特征。深度分层架构,线性和非线性操作员,甚至网络的甚至参数都通过正向传播明确地构造了逐层构造,尽管它们通过背部传播可用于微调。所获得的“白盒”网络的所有组件都具有精确的优化,统计和几何解释。此外,当我们强制执行分类时,所以,所以网络的所有线性运算符自然地变为多通道卷曲。不变设置中的推导表明稀疏性和不变性之间的折衷,并且还表明这种深度卷积网络在光谱域中构建和学习的显着更有效。我们的初步模拟和实验清楚地验证了速率降低目标和相关的Redunet的有效性。所有代码和数据都可用于\ url {https://github.com/ma-lab-berkeley}。
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本文回顾了关于压缩视频质量增强质量的第一个NTIRE挑战,重点是拟议的方法和结果。在此挑战中,采用了新的大型不同视频(LDV)数据集。挑战有三个曲目。Track 1和2的目标是增强HEVC在固定QP上压缩的视频,而Track 3旨在增强X265压缩的视频,以固定的位速率压缩。此外,轨道1和3的质量提高了提高保真度(PSNR)的目标,以及提高感知质量的2个目标。这三个曲目完全吸引了482个注册。在测试阶段,分别提交了12个团队,8支球队和11支球队,分别提交了轨道1、2和3的最终结果。拟议的方法和解决方案衡量视频质量增强的最先进。挑战的首页:https://github.com/renyang-home/ntire21_venh
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标准化技术已成为现代卷积神经网络(Convnets)中的基本组件。特别是,许多最近的作品表明,促进重量的正交性有助于培训深层模型并提高鲁棒性。对于Courmnets,大多数现有方法基于惩罚或归一化矩阵判断或施加卷积核的重量矩阵。这些方法经常摧毁或忽视核的良性卷积结构;因此,对于深扫描器来说,它们通常是昂贵或不切实际的。相比之下,我们介绍了一种简单富有高效的“卷积归一化”(ConvNORM)方法,可以充分利用傅立叶域中的卷积结构,并用作简单的即插即用模块,以方便地结合到任何围栏中。我们的方法是通过最近关于卷积稀疏编码的预处理方法的工作启发,可以有效地促进每个层的频道方向等距。此外,我们表明我们的判断可以降低重量矩阵的层状频谱标准,从而改善网络的嘴唇,导致培训更容易培训和改善深扫描器的鲁棒性。在噪声损坏和生成的对抗网络(GAN)下应用于分类,我们表明CONVNOMOL提高了常见扫描仪(如RENET和GAN性能)的稳健性。我们通过Cifar和Imagenet的数值实验验证了我们的研究结果。
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New architecture GPUs like A100 are now equipped with multi-instance GPU (MIG) technology, which allows the GPU to be partitioned into multiple small, isolated instances. This technology provides more flexibility for users to support both deep learning training and inference workloads, but efficiently utilizing it can still be challenging. The vision of this paper is to provide a more comprehensive and practical benchmark study for MIG in order to eliminate the need for tedious manual benchmarking and tuning efforts. To achieve this vision, the paper presents MIGPerf, an open-source tool that streamlines the benchmark study for MIG. Using MIGPerf, the authors conduct a series of experiments, including deep learning training and inference characterization on MIG, GPU sharing characterization, and framework compatibility with MIG. The results of these experiments provide new insights and guidance for users to effectively employ MIG, and lay the foundation for further research on the orchestration of hybrid training and inference workloads on MIGs. The code and results are released on https://github.com/MLSysOps/MIGProfiler. This work is still in progress and more results will be published soon.
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Learning with noisy-labels has become an important research topic in computer vision where state-of-the-art (SOTA) methods explore: 1) prediction disagreement with co-teaching strategy that updates two models when they disagree on the prediction of training samples; and 2) sample selection to divide the training set into clean and noisy sets based on small training loss. However, the quick convergence of co-teaching models to select the same clean subsets combined with relatively fast overfitting of noisy labels may induce the wrong selection of noisy label samples as clean, leading to an inevitable confirmation bias that damages accuracy. In this paper, we introduce our noisy-label learning approach, called Asymmetric Co-teaching (AsyCo), which introduces novel prediction disagreement that produces more consistent divergent results of the co-teaching models, and a new sample selection approach that does not require small-loss assumption to enable a better robustness to confirmation bias than previous methods. More specifically, the new prediction disagreement is achieved with the use of different training strategies, where one model is trained with multi-class learning and the other with multi-label learning. Also, the new sample selection is based on multi-view consensus, which uses the label views from training labels and model predictions to divide the training set into clean and noisy for training the multi-class model and to re-label the training samples with multiple top-ranked labels for training the multi-label model. Extensive experiments on synthetic and real-world noisy-label datasets show that AsyCo improves over current SOTA methods.
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Learning to predict masked tokens in a sequence has been shown to be a powerful pretraining objective for large-scale language models. After training, such masked language models can provide distributions of tokens conditioned on bidirectional context. In this short draft, we show that such bidirectional conditionals often demonstrate considerable inconsistencies, i.e., they can not be derived from a coherent joint distribution when considered together. We empirically quantify such inconsistencies in the simple scenario of bigrams for two common styles of masked language models: T5-style and BERT-style. For example, we show that T5 models often confuse its own preference regarding two similar bigrams. Such inconsistencies may represent a theoretical pitfall for the research work on sampling sequences based on the bidirectional conditionals learned by BERT-style MLMs. This phenomenon also means that T5-style MLMs capable of infilling will generate discrepant results depending on how much masking is given, which may represent a particular trust issue.
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