Video surveillance has become ubiquitous in the modern world. Mobile devices, surveillance cameras, and IoT devices, all can record video that can violate our privacy. One proposed solution for this is privacy-preserving video, which removes identifying information from the video as it is produced. Several algorithms for this have been proposed, but all of them suffer from scale issues: in order to sufficiently anonymize near-camera objects, distant objects become unidentifiable. In this paper, we propose a scale-invariant method, based on wavelet decomposition.
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细粒度的视觉分类(FGVC)旨在识别子类别的对象。由于级细的级别差异,这是一个非常具有挑战性的任务。现有的研究将大型卷积神经网络或视觉变压器应用为特征提取器,这是极其计算昂贵的。实际上,实际的细粒度识别的场景通常需要更轻薄的移动网络可以离线使用。然而,基本移动网络特征提取能力比大规模模型弱。本文基于轻质MobileNetv2,我们提出了一种具有递归马赛克发生器(RMG-PMSI)的逐步多级交互训练方法。首先,我们提出了一种递归马赛克发生器(RMG),其产生不同阶段的不同粒度的图像。然后,不同阶段的特征通过多级相互作用(MSI)模块,其增强和补充不同阶段的相应特征。最后,使用渐进式训练(P),可以充分利用不同阶段中的模型提取的特征并彼此融合。三个着名的细粒度基准测试的实验表明,RMG-PMSI可以显着提高性能,具有良好的稳健性和可转移性。
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探索近期量子设备的量子应用是具有理论和实际利益的量子信息科学的快速增长领域。建立这种近期量子应用的领先范式是变异量子算法(VQAS)。这些算法使用经典优化器来训练参数化的量子电路以完成某些任务,其中电路通常是随机初始初始初始化的。在这项工作中,我们证明,对于一系列此类随机电路,成本函数的变化范围通过调整电路中的任何局部量子门在具有很高概率的Qubits数量中呈指数级消失。该结果可以自然地统一对基于梯度和无梯度的优化的限制,并揭示对VQA的训练景观的额外严格限制。因此,对VQA的训练性的基本限制是拆开的,这表明具有指数尺寸的希尔伯特空间中优化硬度的基本机制。我们通过代表性VQA的数值模拟进一步展示了结果的有效性。我们认为,这些结果将加深我们对VQA的可扩展性的理解,并阐明了搜索具有优势的近期量子应用程序。
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知识蒸馏已成为获得紧凑又有效模型的重要方法。为实现这一目标,培训小型学生模型以利用大型训练有素的教师模型的知识。然而,由于教师和学生之间的能力差距,学生的表现很难达到老师的水平。关于这个问题,现有方法建议通过代理方式减少教师知识的难度。我们认为这些基于代理的方法忽视了教师的知识损失,这可能导致学生遇到容量瓶颈。在本文中,我们从新的角度来缓解能力差距问题,以避免知识损失的目的。我们建议通过对抗性协作学习建立一个更有力的学生,而不是牺牲教师的知识。为此,我们进一步提出了一种逆势协作知识蒸馏(ACKD)方法,有效提高了知识蒸馏的性能。具体来说,我们用多个辅助学习者构建学生模型。同时,我们设计了对抗的对抗性协作模块(ACM),引入注意机制和对抗的学习,以提高学生的能力。四个分类任务的广泛实验显示了拟议的Ackd的优越性。
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知识蒸馏是通过知识转移模型压缩的有效稳定的方法。传统知识蒸馏(KD)是将来自大型和训练有素的教师网络的知识转移到小型学生网络,这是一种单向过程。最近,已经提出了深度相互学习(DML)来帮助学生网络协同和同时学习。然而,据我们所知,KD和DML从未在统一的框架中共同探索,以解决知识蒸馏问题。在本文中,我们调查教师模型在KD中支持更值得信赖的监督信号,而学生则在DML中捕获教师的类似行为。基于这些观察,我们首先建议将KD与DML联合在统一的框架中。此外,我们提出了一个半球知识蒸馏(SOKD)方法,有效提高了学生和教师的表现。在这种方法中,我们在DML中介绍了同伴教学培训时尚,以缓解学生的模仿困难,并利用KD训练有素的教师提供的监督信号。此外,我们还显示我们的框架可以轻松扩展到基于功能的蒸馏方法。在CiFAR-100和Imagenet数据集上的广泛实验证明了所提出的方法实现了最先进的性能。
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We study the problem of 3D object generation. We propose a novel framework, namely 3D Generative Adversarial Network (3D-GAN), which generates 3D objects from a probabilistic space by leveraging recent advances in volumetric convolutional networks and generative adversarial nets. The benefits of our model are three-fold: first, the use of an adversarial criterion, instead of traditional heuristic criteria, enables the generator to capture object structure implicitly and to synthesize high-quality 3D objects; second, the generator establishes a mapping from a low-dimensional probabilistic space to the space of 3D objects, so that we can sample objects without a reference image or CAD models, and explore the 3D object manifold; third, the adversarial discriminator provides a powerful 3D shape descriptor which, learned without supervision, has wide applications in 3D object recognition. Experiments demonstrate that our method generates high-quality 3D objects, and our unsupervisedly learned features achieve impressive performance on 3D object recognition, comparable with those of supervised learning methods.
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Unsupervised domain adaptation (UDA) for semantic segmentation is a promising task freeing people from heavy annotation work. However, domain discrepancies in low-level image statistics and high-level contexts compromise the segmentation performance over the target domain. A key idea to tackle this problem is to perform both image-level and feature-level adaptation jointly. Unfortunately, there is a lack of such unified approaches for UDA tasks in the existing literature. This paper proposes a novel UDA pipeline for semantic segmentation that unifies image-level and feature-level adaptation. Concretely, for image-level domain shifts, we propose a global photometric alignment module and a global texture alignment module that align images in the source and target domains in terms of image-level properties. For feature-level domain shifts, we perform global manifold alignment by projecting pixel features from both domains onto the feature manifold of the source domain; and we further regularize category centers in the source domain through a category-oriented triplet loss and perform target domain consistency regularization over augmented target domain images. Experimental results demonstrate that our pipeline significantly outperforms previous methods. In the commonly tested GTA5$\rightarrow$Cityscapes task, our proposed method using Deeplab V3+ as the backbone surpasses previous SOTA by 8%, achieving 58.2% in mIoU.
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Different people speak with diverse personalized speaking styles. Although existing one-shot talking head methods have made significant progress in lip sync, natural facial expressions, and stable head motions, they still cannot generate diverse speaking styles in the final talking head videos. To tackle this problem, we propose a one-shot style-controllable talking face generation framework. In a nutshell, we aim to attain a speaking style from an arbitrary reference speaking video and then drive the one-shot portrait to speak with the reference speaking style and another piece of audio. Specifically, we first develop a style encoder to extract dynamic facial motion patterns of a style reference video and then encode them into a style code. Afterward, we introduce a style-controllable decoder to synthesize stylized facial animations from the speech content and style code. In order to integrate the reference speaking style into generated videos, we design a style-aware adaptive transformer, which enables the encoded style code to adjust the weights of the feed-forward layers accordingly. Thanks to the style-aware adaptation mechanism, the reference speaking style can be better embedded into synthesized videos during decoding. Extensive experiments demonstrate that our method is capable of generating talking head videos with diverse speaking styles from only one portrait image and an audio clip while achieving authentic visual effects. Project Page: https://github.com/FuxiVirtualHuman/styletalk.
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Witnessing the impressive achievements of pre-training techniques on large-scale data in the field of computer vision and natural language processing, we wonder whether this idea could be adapted in a grab-and-go spirit, and mitigate the sample inefficiency problem for visuomotor driving. Given the highly dynamic and variant nature of the input, the visuomotor driving task inherently lacks view and translation invariance, and the visual input contains massive irrelevant information for decision making, resulting in predominant pre-training approaches from general vision less suitable for the autonomous driving task. To this end, we propose PPGeo (Policy Pre-training via Geometric modeling), an intuitive and straightforward fully self-supervised framework curated for the policy pretraining in visuomotor driving. We aim at learning policy representations as a powerful abstraction by modeling 3D geometric scenes on large-scale unlabeled and uncalibrated YouTube driving videos. The proposed PPGeo is performed in two stages to support effective self-supervised training. In the first stage, the geometric modeling framework generates pose and depth predictions simultaneously, with two consecutive frames as input. In the second stage, the visual encoder learns driving policy representation by predicting the future ego-motion and optimizing with the photometric error based on current visual observation only. As such, the pre-trained visual encoder is equipped with rich driving policy related representations and thereby competent for multiple visuomotor driving tasks. Extensive experiments covering a wide span of challenging scenarios have demonstrated the superiority of our proposed approach, where improvements range from 2% to even over 100% with very limited data. Code and models will be available at https://github.com/OpenDriveLab/PPGeo.
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Increasing research interests focus on sequential recommender systems, aiming to model dynamic sequence representation precisely. However, the most commonly used loss function in state-of-the-art sequential recommendation models has essential limitations. To name a few, Bayesian Personalized Ranking (BPR) loss suffers the vanishing gradient problem from numerous negative sampling and predictionbiases; Binary Cross-Entropy (BCE) loss subjects to negative sampling numbers, thereby it is likely to ignore valuable negative examples and reduce the training efficiency; Cross-Entropy (CE) loss only focuses on the last timestamp of the training sequence, which causes low utilization of sequence information and results in inferior user sequence representation. To avoid these limitations, in this paper, we propose to calculate Cumulative Cross-Entropy (CCE) loss over the sequence. CCE is simple and direct, which enjoys the virtues of painless deployment, no negative sampling, and effective and efficient training. We conduct extensive experiments on five benchmark datasets to demonstrate the effectiveness and efficiency of CCE. The results show that employing CCE loss on three state-of-the-art models GRU4Rec, SASRec, and S3-Rec can reach 125.63%, 69.90%, and 33.24% average improvement of full ranking NDCG@5, respectively. Using CCE, the performance curve of the models on the test data increases rapidly with the wall clock time, and is superior to that of other loss functions in almost the whole process of model training.
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