Face Anti-spoofing (FAS) is essential to secure face recognition systems from various physical attacks. However, recent research generally focuses on short-distance applications (i.e., phone unlocking) while lacking consideration of long-distance scenes (i.e., surveillance security checks). In order to promote relevant research and fill this gap in the community, we collect a large-scale Surveillance High-Fidelity Mask (SuHiFiMask) dataset captured under 40 surveillance scenes, which has 101 subjects from different age groups with 232 3D attacks (high-fidelity masks), 200 2D attacks (posters, portraits, and screens), and 2 adversarial attacks. In this scene, low image resolution and noise interference are new challenges faced in surveillance FAS. Together with the SuHiFiMask dataset, we propose a Contrastive Quality-Invariance Learning (CQIL) network to alleviate the performance degradation caused by image quality from three aspects: (1) An Image Quality Variable module (IQV) is introduced to recover image information associated with discrimination by combining the super-resolution network. (2) Using generated sample pairs to simulate quality variance distributions to help contrastive learning strategies obtain robust feature representation under quality variation. (3) A Separate Quality Network (SQN) is designed to learn discriminative features independent of image quality. Finally, a large number of experiments verify the quality of the SuHiFiMask dataset and the superiority of the proposed CQIL.
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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.
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Most existing distillation methods ignore the flexible role of the temperature in the loss function and fix it as a hyper-parameter that can be decided by an inefficient grid search. In general, the temperature controls the discrepancy between two distributions and can faithfully determine the difficulty level of the distillation task. Keeping a constant temperature, i.e., a fixed level of task difficulty, is usually sub-optimal for a growing student during its progressive learning stages. In this paper, we propose a simple curriculum-based technique, termed Curriculum Temperature for Knowledge Distillation (CTKD), which controls the task difficulty level during the student's learning career through a dynamic and learnable temperature. Specifically, following an easy-to-hard curriculum, we gradually increase the distillation loss w.r.t. the temperature, leading to increased distillation difficulty in an adversarial manner. As an easy-to-use plug-in technique, CTKD can be seamlessly integrated into existing knowledge distillation frameworks and brings general improvements at a negligible additional computation cost. Extensive experiments on CIFAR-100, ImageNet-2012, and MS-COCO demonstrate the effectiveness of our method. Our code is available at https://github.com/zhengli97/CTKD.
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In this paper, we study the problem of visual grounding by considering both phrase extraction and grounding (PEG). In contrast to the previous phrase-known-at-test setting, PEG requires a model to extract phrases from text and locate objects from images simultaneously, which is a more practical setting in real applications. As phrase extraction can be regarded as a $1$D text segmentation problem, we formulate PEG as a dual detection problem and propose a novel DQ-DETR model, which introduces dual queries to probe different features from image and text for object prediction and phrase mask prediction. Each pair of dual queries is designed to have shared positional parts but different content parts. Such a design effectively alleviates the difficulty of modality alignment between image and text (in contrast to a single query design) and empowers Transformer decoder to leverage phrase mask-guided attention to improve performance. To evaluate the performance of PEG, we also propose a new metric CMAP (cross-modal average precision), analogous to the AP metric in object detection. The new metric overcomes the ambiguity of Recall@1 in many-box-to-one-phrase cases in phrase grounding. As a result, our PEG pre-trained DQ-DETR establishes new state-of-the-art results on all visual grounding benchmarks with a ResNet-101 backbone. For example, it achieves $91.04\%$ and $83.51\%$ in terms of recall rate on RefCOCO testA and testB with a ResNet-101 backbone. Code will be availabl at \url{https://github.com/IDEA-Research/DQ-DETR}.
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This paper presents a new hierarchical vision Transformer for image style transfer, called Strips Window Attention Transformer (S2WAT), which serves as an encoder of encoder-transfer-decoder architecture. With hierarchical features, S2WAT can leverage proven techniques in other fields of computer vision, such as feature pyramid networks (FPN) or U-Net, to image style transfer in future works. However, the existing window-based Transformers will cause a problem that the stylized images will be grid-like when introduced into image style transfer directly. To solve this problem, we propose S2WAT whose representation is computed with Strips Window Attention (SpW Attention). The SpW Attention can integrate both local information and long-range dependencies in horizontal and vertical directions by a novel feature fusion scheme named Attn Merge. Qualitative and quantitative experiments demonstrate that S2WAT achieves comparable performance to state-of-the-art CNN-based, Flow-based, and Transformer-based approaches. The code and models are available at https://github.com/AlienZhang1996/S2WAT.
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Synthetic voice and splicing audio clips have been generated to spoof Internet users and artificial intelligence (AI) technologies such as voice authentication. Existing research work treats spoofing countermeasures as a binary classification problem: bonafide vs. spoof. This paper extends the existing Res2Net by involving the recent Conformer block to further exploit the local patterns on acoustic features. Experimental results on ASVspoof 2019 database show that the proposed SE-Res2Net-Conformer architecture is able to improve the spoofing countermeasures performance for the logical access scenario. In addition, this paper also proposes to re-formulate the existing audio splicing detection problem. Instead of identifying the complete splicing segments, it is more useful to detect the boundaries of the spliced segments. Moreover, a deep learning approach can be used to solve the problem, which is different from the previous signal processing techniques.
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在现实世界中的问题回答场景中,将表格和文本内容均结合的混合形式吸引了越来越多的关注,其中数值推理问题是最典型和最具挑战性的问题之一。现有方法通常采用编码器框架来表示混合内容并生成答案。但是,它无法捕获编码器侧数值,表格架构和文本信息之间的丰富关系。解码器使用一个简单的预定义运算符分类器,该分类器的灵活性不足以处理具有不同表达式的数值推理过程。为了解决这些问题,本文提出了一个\ textbf {re} lational \ textbf {g} raph增强\ textbf {h} ybrid table-text \ textbf {n}带有\ textbf {t textbf {t text} ree decoder(\ textbff recoder(\ textbf) {reghnt})。它模拟了对表 - 文本混合内容的回答的数值问题,作为表达树的生成任务。此外,我们提出了一种新颖的关系图建模方法,该方法模拟了问题,表和段落之间的对齐方式。我们验证了公开可用的Table-Text混合质量质量质量标准(TAT-QA)的模型。拟议的reghnt显着胜过基线模型,并实现最新结果\脚注{我们在〜\ url {https://github.com/lfy79001/reghnt}}}〜(20222)公开发布了源代码和数据-05-05)。
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3D多对象跟踪(MOT)确保在连续动态检测过程中保持一致性,有利于自动驾驶中随后的运动计划和导航任务。但是,基于摄像头的方法在闭塞情况下受到影响,准确跟踪基于激光雷达的方法的对象的不规则运动可能是具有挑战性的。某些融合方法效果很好,但不认为在遮挡下出现外观特征的不可信问题。同时,错误检测问题也显着影响跟踪。因此,我们根据组合的外观运动优化(Camo-Mot)提出了一种新颖的相机融合3D MOT框架,该框架使用相机和激光镜数据,并大大减少了由遮挡和错误检测引起的跟踪故障。对于遮挡问题,我们是第一个提出遮挡头来有效地选择最佳对象外观的人,从而减少了闭塞的影响。为了减少错误检测在跟踪中的影响,我们根据置信得分设计一个运动成本矩阵,从而提高了3D空间中的定位和对象预测准确性。由于现有的多目标跟踪方法仅考虑一个类别,因此我们还建议建立多类损失,以在多类别场景中实现多目标跟踪。在Kitti和Nuscenes跟踪基准测试上进行了一系列验证实验。我们提出的方法在KITTI测试数据集上的所有多模式MOT方法中实现了最先进的性能和最低的身份开关(IDS)值(CAR为23,行人为137)。并且我们提出的方法在Nuscenes测试数据集上以75.3%的AMOTA进行了所有算法中的最新性能。
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基于图像的3D检测是自主驾驶感知系统的必不可少的组成部分。但是,它仍然受到不满意的表现,这是有限的培训数据的主要原因之一。不幸的是,在3D空间中注释对象是极度时间/资源消耗的,这使得很难任意扩展训练集。在这项工作中,我们专注于半监督的方式,并探索更便宜的替代方案(即伪标记)的可行性,以利用未标记的数据。为此,我们进行了广泛的实验,以研究伪标签是否可以在不同环境下为基线模型提供有效的监督。实验结果不仅证明了基于图像的3D检测的伪标记机制的有效性(例如,在单眼设置下,我们在没有铃铛和哨声的Kitti-3D测试集上实现了20.23 AP,用于中等水平,从6.03 AP),但还显示了几个有趣且值得注意的发现(例如,经过伪标签训练的模型的性能要比基于相同培训数据的地面真相注释训练的表现更好)。我们希望这项工作可以在半监督环境下为基于图像的3D检测社区提供见解。代码,伪标签和预培训模型将公开可用。
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两栖地面汽车将飞行和驾驶模式融合在一起,以实现更灵活的空中行动能力,并且最近受到了越来越多的关注。通过分析现有的两栖车辆,我们强调了在复杂的三维城市运输系统中有效使用两栖车辆的自动驾驶功能。我们审查并总结了现有两栖车辆设计中智能飞行驾驶的关键促成技术,确定主要的技术障碍,并提出潜在的解决方案,以实现未来的研究和创新。本文旨在作为研究和开发智能两栖车辆的指南,以实现未来的城市运输。
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