源相机识别工具辅助图像法医调查人员将讨论的图像与可疑摄像机相关联。已经基于在获取期间图像中留下的微妙迹线的分析来开发了各种技术。由传感器缺陷引起的照片响应非均匀性(PRNU)噪声模式已被证明是识别源相机的有效方法。现有文献表明,PRNU是唯一是特定于设备的指纹,并且能够识别确切的源设备。然而,PRNU易受相机设置,图像内容,图像处理操作和反务攻击的影响。法医调查员不知道反务攻击​​或附带图像操纵有误导的风险。两个PRNU匹配期间的空间同步要求也代表了PRNU的一个主要限制。近年来,基于深度学习的方法在识别源相机模型方面取得了成功。然而,通过这些数据驱动方法识别相同模型的各个摄像机仍然不令人满意。在本文中,我们可以在数字图像中阐明能够识别相同模型的各个摄像机的数字图像中的新的强大数据驱动设备特定指纹。发现新设备指纹是独立于无关的,随机性的,全局可用,解决空间同步问题。与驻留在高频带中的PRNU不同,从低频和中频频带提取新的设备指纹,这解析了PRNU无法抗争的脆弱问题。我们对各种数据集的实验表明,新的指纹对图像操纵具有高度弹性,例如旋转,伽马校正和侵略性JPEG压缩。
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Nonconvex optimization is central in solving many machine learning problems, in which block-wise structure is commonly encountered. In this work, we propose cyclic block coordinate methods for nonconvex optimization problems with non-asymptotic gradient norm guarantees. Our convergence analysis is based on a gradient Lipschitz condition with respect to a Mahalanobis norm, inspired by a recent progress on cyclic block coordinate methods. In deterministic settings, our convergence guarantee matches the guarantee of (full-gradient) gradient descent, but with the gradient Lipschitz constant being defined w.r.t.~the Mahalanobis norm. In stochastic settings, we use recursive variance reduction to decrease the per-iteration cost and match the arithmetic operation complexity of current optimal stochastic full-gradient methods, with a unified analysis for both finite-sum and infinite-sum cases. We further prove the faster, linear convergence of our methods when a Polyak-{\L}ojasiewicz (P{\L}) condition holds for the objective function. To the best of our knowledge, our work is the first to provide variance-reduced convergence guarantees for a cyclic block coordinate method. Our experimental results demonstrate the efficacy of the proposed variance-reduced cyclic scheme in training deep neural nets.
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Existing 3D scene stylization methods employ an arbitrary style reference to transfer textures and colors as styles without establishing meaningful semantic correspondences. We present Reference-Based Non-Photorealistic Radiance Fields, i.e., Ref-NPR. It is a controllable scene stylization method utilizing radiance fields to stylize a 3D scene, with a single stylized 2D view taken as reference. To achieve decent results, we propose a ray registration process based on the stylized reference view to obtain pseudo-ray supervision in novel views, and exploit the semantic correspondence in content images to fill occluded regions with perceptually similar styles. Combining these operations, Ref-NPR generates non-photorealistic and continuous novel view sequences with a single reference while obtaining reasonable stylization in occluded regions. Experiments show that Ref-NPR significantly outperforms other scene and video stylization methods in terms of both visual quality and semantic correspondence. Code and data will be made publicly available.
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声音是现实世界中最有用,最丰富的方式之一,同时可以通过可以放置在移动设备上的小型和便宜的传感器来感知不接触。尽管深度学习能够从多个感官输入中提取信息,但很少有声音控制和学习机器人动作。对于无监督的强化学习,预计代理人将积极地收集经验,并以一种自制的方式共同学习代表和政策。我们使用基于物理的声音模拟来构建逼真的机器人操作场景,并提出内在的好奇模块(ISCM)。 ISCM向加强学习者提供反馈,以学习强大的表示并奖励更有效的探索行为。我们在适应过程中对启用声音进行了启用的声音实验,并表明ISCM所学的表示形式优于仅视力基线的基本线和预训练的策略,可以在应用于下游任务时加速学习过程。
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瀑布推荐系统(RS)是移动应用程序中RS的流行形式,是推荐的项目流,这些项目由连续页面组成,可以通过滚动浏览。在Waterfall RS中,当用户完成浏览页面时,Edge(例如,手机)将向Cloud Server发送请求,以获取新的建议页面,称为分页请求机制。 RSS通常将大量项目放入一页中,以减少众多分页请求中的过度资源消耗,但是,这将降低RSS根据用户的实时兴趣及时续订建议的能力,并导致贫穷的用户。经验。直观地,在页面内插入其他请求以更新频率的建议可以减轻问题。但是,以前的尝试,包括非自适应策略(例如,统一插入请求)最终会导致资源过度消费。为此,我们设想了一项名为智能请求策略设计(IRSD)的Edge Intelligence的新学习任务。它旨在通过根据用户的实时意图确定请求插入的适当情况来提高瀑布RSS的有效性。此外,我们提出了一种新的自适应请求插入策略的范式,名为基于Uplift的On-Ending Smart请求框架(AdareQuest)。 AdareQuest 1)通过将实时行为与基于基于注意力的神经网络相匹配的历史兴趣来捕获用户意图的动态变化。 2)估计根据因果推理插入的请求带来的用户购买的反事实提升。 3)通过在在线资源约束下最大化效用功能来确定最终请求插入策略。我们在离线数据集和在线A/B测试上进行了广泛的实验,以验证AdareQuest的有效性。
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We study stochastic monotone inclusion problems, which widely appear in machine learning applications, including robust regression and adversarial learning. We propose novel variants of stochastic Halpern iteration with recursive variance reduction. In the cocoercive -- and more generally Lipschitz-monotone -- setup, our algorithm attains $\epsilon$ norm of the operator with $\mathcal{O}(\frac{1}{\epsilon^3})$ stochastic operator evaluations, which significantly improves over state of the art $\mathcal{O}(\frac{1}{\epsilon^4})$ stochastic operator evaluations required for existing monotone inclusion solvers applied to the same problem classes. We further show how to couple one of the proposed variants of stochastic Halpern iteration with a scheduled restart scheme to solve stochastic monotone inclusion problems with ${\mathcal{O}}(\frac{\log(1/\epsilon)}{\epsilon^2})$ stochastic operator evaluations under additional sharpness or strong monotonicity assumptions.
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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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Compressed videos often exhibit visually annoying artifacts, known as Perceivable Encoding Artifacts (PEAs), which dramatically degrade video visual quality. Subjective and objective measures capable of identifying and quantifying various types of PEAs are critical in improving visual quality. In this paper, we investigate the influence of four spatial PEAs (i.e. blurring, blocking, bleeding, and ringing) and two temporal PEAs (i.e. flickering and floating) on video quality. For spatial artifacts, we propose a visual saliency model with a low computational cost and higher consistency with human visual perception. In terms of temporal artifacts, self-attention based TimeSFormer is improved to detect temporal artifacts. Based on the six types of PEAs, a quality metric called Saliency-Aware Spatio-Temporal Artifacts Measurement (SSTAM) is proposed. Experimental results demonstrate that the proposed method outperforms state-of-the-art metrics. We believe that SSTAM will be beneficial for optimizing video coding techniques.
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Image Virtual try-on aims at replacing the cloth on a personal image with a garment image (in-shop clothes), which has attracted increasing attention from the multimedia and computer vision communities. Prior methods successfully preserve the character of clothing images, however, occlusion remains a pernicious effect for realistic virtual try-on. In this work, we first present a comprehensive analysis of the occlusions and categorize them into two aspects: i) Inherent-Occlusion: the ghost of the former cloth still exists in the try-on image; ii) Acquired-Occlusion: the target cloth warps to the unreasonable body part. Based on the in-depth analysis, we find that the occlusions can be simulated by a novel semantically-guided mixup module, which can generate semantic-specific occluded images that work together with the try-on images to facilitate training a de-occlusion try-on (DOC-VTON) framework. Specifically, DOC-VTON first conducts a sharpened semantic parsing on the try-on person. Aided by semantics guidance and pose prior, various complexities of texture are selectively blending with human parts in a copy-and-paste manner. Then, the Generative Module (GM) is utilized to take charge of synthesizing the final try-on image and learning to de-occlusion jointly. In comparison to the state-of-the-art methods, DOC-VTON achieves better perceptual quality by reducing occlusion effects.
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Panoptic Part Segmentation (PPS) unifies panoptic segmentation and part segmentation into one task. Previous works utilize separated approaches to handle thing, stuff, and part predictions without shared computation and task association. We aim to unify these tasks at the architectural level, designing the first end-to-end unified framework named Panoptic-PartFormer. Moreover, we find the previous metric PartPQ biases to PQ. To handle both issues, we make the following contributions: Firstly, we design a meta-architecture that decouples part feature and things/stuff feature, respectively. We model things, stuff, and parts as object queries and directly learn to optimize all three forms of prediction as a unified mask prediction and classification problem. We term our model as Panoptic-PartFormer. Secondly, we propose a new metric Part-Whole Quality (PWQ) to better measure such task from both pixel-region and part-whole perspectives. It can also decouple the error for part segmentation and panoptic segmentation. Thirdly, inspired by Mask2Former, based on our meta-architecture, we propose Panoptic-PartFormer++ and design a new part-whole cross attention scheme to further boost part segmentation qualities. We design a new part-whole interaction method using masked cross attention. Finally, the extensive ablation studies and analysis demonstrate the effectiveness of both Panoptic-PartFormer and Panoptic-PartFormer++. Compared with previous Panoptic-PartFormer, our Panoptic-PartFormer++ achieves 2% PartPQ and 3% PWQ improvements on the Cityscapes PPS dataset and 5% PartPQ on the Pascal Context PPS dataset. On both datasets, Panoptic-PartFormer++ achieves new state-of-the-art results with a significant cost drop of 70% on GFlops and 50% on parameters. Our models can serve as a strong baseline and aid future research in PPS. Code will be available.
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