恢复面部和文档图像的检测是一项重要的法医任务。经过深入的学习,面部抗散热器(FAS)和重新接收的文件检测的表现得到了显着改善。但是,对于法医提示较弱的样品,表演尚不令人满意。可以量化法医提示的数量,以允许可靠的法医结果。在这项工作中,我们提出了一个放大性评估网络,以量化质疑样品的允许性。在实际重新接收检测过程之前,将拒绝低固定性样品,以提高重新接收检测系统的效率。我们首先提取与图像质量评估和法医任务相关的判定性特征。通过利用图像质量和法医功能的法医应用的域知识,我们定义了特定于任务的规定类别和特征空间中的初始化位置。根据提取的功能和定义的中心,我们使用跨凝结损失训练提出的法医评估网络(FANET),并使用基于动量的更新方法更新中心。我们将受过训练的粉丝与实际重新接收检测方案相结合,并在抗spofing和重新接收的文档检测任务中。实验结果表明,对于基于CNN的FAS方案而言,狂热者通过拒绝最低30%放大性得分的样本,将EERS从Rose to IDIAP方案下的ERS降低到19.23%。在被拒绝的样品中,FAS方案的性能很差,EER高达56.48%。在FAS中的最新方法和重新接收的文档检测任务中,已经观察到了拒绝低差异性样品的类似性能。据我们所知,这是评估重新捕获文档图像并提高系统效率的第一份工作。
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There is a growing interest in developing unlearnable examples (UEs) against visual privacy leaks on the Internet. UEs are training samples added with invisible but unlearnable noise, which have been found can prevent unauthorized training of machine learning models. UEs typically are generated via a bilevel optimization framework with a surrogate model to remove (minimize) errors from the original samples, and then applied to protect the data against unknown target models. However, existing UE generation methods all rely on an ideal assumption called label-consistency, where the hackers and protectors are assumed to hold the same label for a given sample. In this work, we propose and promote a more practical label-agnostic setting, where the hackers may exploit the protected data quite differently from the protectors. E.g., a m-class unlearnable dataset held by the protector may be exploited by the hacker as a n-class dataset. Existing UE generation methods are rendered ineffective in this challenging setting. To tackle this challenge, we present a novel technique called Unlearnable Clusters (UCs) to generate label-agnostic unlearnable examples with cluster-wise perturbations. Furthermore, we propose to leverage VisionandLanguage Pre-trained Models (VLPMs) like CLIP as the surrogate model to improve the transferability of the crafted UCs to diverse domains. We empirically verify the effectiveness of our proposed approach under a variety of settings with different datasets, target models, and even commercial platforms Microsoft Azure and Baidu PaddlePaddle.
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Although significant progress has been made in few-shot learning, most of existing few-shot learning methods require supervised pre-training on a large amount of samples of base classes, which limits their generalization ability in real world application. Recently, large-scale self-supervised vision-language models (e.g., CLIP) have provided a new paradigm for transferable visual representation learning. However, the pre-trained VLPs may neglect detailed visual information that is difficult to describe by language sentences, but important for learning an effective classifier in few-shot classification. To address the above problem, we propose a new framework, named Semantic-guided Visual Adapting (SgVA), which can effectively extend vision-language pre-trained models to produce discriminative task-specific visual features by comprehensively using a vision-specific contrastive loss, a cross-modal contrastive loss, and an implicit knowledge distillation. The implicit knowledge distillation is designed to transfer the fine-grained cross-modal knowledge to guide the updating of the vision adapter. State-of-the-art results on 13 datasets demonstrate that the adapted visual features can well complement the cross-modal features to improve few-shot image classification.
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Pre-trained Vision-Language Models (VLMs) such as CLIP have shown impressive generalization capability in downstream vision tasks with appropriate text prompts. Instead of designing prompts manually, Context Optimization (CoOp) has been recently proposed to learn continuous prompts using task-specific training data. Despite the performance improvements on downstream tasks, several studies have reported that CoOp suffers from the overfitting issue in two aspects: (i) the test accuracy on base classes first gets better and then gets worse during training; (ii) the test accuracy on novel classes keeps decreasing. However, none of the existing studies can understand and mitigate such overfitting problem effectively. In this paper, we first explore the cause of overfitting by analyzing the gradient flow. Comparative experiments reveal that CoOp favors generalizable and spurious features in the early and later training stages respectively, leading to the non-overfitting and overfitting phenomenon. Given those observations, we propose Subspace Prompt Tuning (SubPT) to project the gradients in back-propagation onto the low-rank subspace spanned by the early-stage gradient flow eigenvectors during the entire training process, and successfully eliminate the overfitting problem. Besides, we equip CoOp with Novel Feature Learner (NFL) to enhance the generalization ability of the learned prompts onto novel categories beyond the training set, needless of image training data. Extensive experiments on 11 classification datasets demonstrate that SubPT+NFL consistently boost the performance of CoOp and outperform the state-of-the-art approach CoCoOp. Experiments on more challenging vision downstream tasks including open-vocabulary object detection and zero-shot semantic segmentation also verify the effectiveness of the proposed method. Codes can be found at https://tinyurl.com/mpe64f89.
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数字艺术合成在多媒体社区中受到越来越多的关注,因为有效地与公众参与了艺术。当前的数字艺术合成方法通常使用单模式输入作为指导,从而限制了模型的表现力和生成结果的多样性。为了解决这个问题,我们提出了多模式引导的艺术品扩散(MGAD)模型,该模型是一种基于扩散的数字艺术品生成方法,它利用多模式提示作为控制无分类器扩散模型的指导。此外,对比度语言图像预处理(剪辑)模型用于统一文本和图像模式。关于生成的数字艺术绘画质量和数量的广泛实验结果证实了扩散模型和多模式指导的组合有效性。代码可从https://github.com/haha-lisa/mgad-multimodal-guided-artwork-diffusion获得。
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激活功能对于神经网络引入非线性至关重要。许多经验实验已经验证了各种激活功能,但有关激活功能的理论研究不足。在这项工作中,我们研究了激活功能对梯度方差的影响,并提出了一种使激活函数正常化的方法,以使所有层的梯度方差保持相同,以便神经网络可以实现更好的收敛性。首先,我们补充了先前的工作,以分析梯度方差的分析,在这种梯度的方差中,激活功能的影响仅在理想化的初始状态下,几乎不能保存在训练过程中,并获得了良好激活功能应尽可能满足的属性。其次,我们提供了一种将激活功能归一化并证明其对普遍激活功能的有效性的方法。通过观察实验,我们发现收敛速度与我们在前一部分中得出的属性大致相关。我们针对共同的激活函数进行了归一化激活函数的实验。结果表明,我们的方法始终优于其非标准化对应物。例如,就TOP-1的准确性而言,用CIFAR-100的RESNET50在RESNET50上归一化的Swish swilla swish swish swish。我们的方法通过简单地在完全连接的网络和残留网络中替换其归一化功能来改善性能。
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图形结构化数据通常在自然界中具有动态字符,例如,在许多现实世界中,链接和节点的添加。近年来见证了对这种图形数据进行建模的动态图神经网络所支付的越来越多的注意力,几乎所有现有方法都假设,当建立新的链接时,应通过学习时间动态来传播邻居节点的嵌入。新的信息。但是,这种方法遭受了这样的限制,如果新连接引入的节点包含嘈杂的信息,那么将其知识传播到其他节点是不可靠的,甚至导致模型崩溃。在本文中,我们提出了Adanet:通过增强动态图神经网络的强化知识适应框架。与以前的方法相反,一旦添加了新链接,就立即更新邻居节点的嵌入方式,Adanet试图自适应地确定由于涉及的新链接而应更新哪些节点。考虑到是否更新一个邻居节点的嵌入的决定将对其他邻居节点产生很大的影响,因此,我们将节点更新的选择作为序列决策问题,并通过强化学习解决此问题。通过这种方式,我们可以将知识自适应地传播到其他节点,以学习健壮的节点嵌入表示。据我们所知,我们的方法构成了通过强化学习的动态图神经网络来探索强大知识适应的首次尝试。在三个基准数据集上进行的广泛实验表明,Adanet可以实现最新的性能。此外,我们通过在数据集中添加不同程度的噪声来执行实验,并定量和定性地说明ADANET的鲁棒性。
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盲人面部修复(BFR)旨在从低品质的图像中恢复高质量的面部图像,并通常求助于面部先验,以改善恢复性能。但是,当前的方法仍然遇到两个主要困难:1)如何在不进行大规模调整的情况下得出强大的网络体系结构; 2)如何从一个网络中的多个面部先验捕获互补信息以提高恢复性能。为此,我们提出了一个面部修复搜索网络(FRSNET),以适应我们指定的搜索空间内的合适特征提取体系结构,这可以直接有助于恢复质量。在FRSNET的基础上,我们通过多个学习方案进一步设计了多个面部先验搜索网络(MFPSNET)。 MFPSNET最佳地从不同的面部先验中提取信息,并将信息融合到图像特征中,以确保保留外部指导和内部特征。通过这种方式,MFPSNet充分利用了语义级别(解析图),几何级别(面部热图),参考级别(面部词典)和像素级(降级图像)信息,从而产生忠实且逼真的图像。定量和定性实验表明,MFPSNET在合成和现实世界数据集上对最先进的BFR方法表现出色。这些代码可公开可用:https://github.com/yyj1ang/mfpsnet。
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知识蒸馏(KD)证明了其有效性,可以提高图形神经网络(GNN)的性能,其目标是将知识从更深的教师gnn蒸馏成较浅的学生GNN。但是,由于众所周知的过度参数和过度光滑的问题,实际上很难培训令人满意的教师GNN,从而导致实际应用中的知识转移无效。在本文中,我们通过对GNN的加强学习(称为FreeKD)提出了第一个自由方向知识蒸馏框架,而这不再需要提供更深入的良好优化的教师GNN。我们工作的核心思想是协作建立两个较浅的GNN,以通过以层次结构方式通过加强学习来交流知识。正如我们观察到的一个典型的GNN模型在训练过程中通常在不同节点的表现更好,更差的表现,我们设计了一种动态和自由方向的知识转移策略,该策略由两个级别的动作组成:1)节点级别的动作决定了知识的方向。两个网络的相应节点之间的传输;然后2)结构级的动作确定了要传播的节点级别生成的局部结构。从本质上讲,我们的FreeKD是一个一般且原则性的框架,可以自然与不同架构的GNN兼容。在五个基准数据集上进行的广泛实验表明,我们的FreeKD在很大的边距上优于两个基本GNN,并显示了其对各种GNN的功效。更令人惊讶的是,我们的FreeKD比传统的KD算法具有可比性甚至更好的性能,这些KD算法将知识从更深,更强大的教师GNN中提取。
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盲面修复(BFR)旨在从相应的低质量(LQ)输入中构建高质量(HQ)面部图像。最近,已经提出了许多BFR方法,并取得了杰出的成功。但是,这些方法经过私人合成的数据集进行了培训或评估,这使得与后续方法相比的方法是不可行的。为了解决这个问题,我们首先合成两个称为EDFEACE-CELEB-1M(BFR128)和EDFACE-CELEB-150K(BFR512)的盲面恢复基准数据集。在五个设置下,将最先进的方法在它们的五个设置下进行了基准测试,包括模糊,噪声,低分辨率,JPEG压缩伪像及其组合(完全退化)。为了使比较更全面,应用了五个广泛使用的定量指标和两个任务驱动的指标,包括平均面部标志距离(AFLD)和平均面部ID余弦相似性(AFICS)。此外,我们开发了一个有效的基线模型,称为Swin Transformer U-NET(昏迷)。带有U-NET体系结构的昏迷器应用了注意机制和移动的窗口方案,以捕获远程像素相互作用,并更多地关注重要功能,同时仍受到有效训练。实验结果表明,所提出的基线方法对各种BFR任务的SOTA方法表现出色。
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