捕获比窄FOV相机的宽视野(FOV)相机,其捕获更大的场景区域,用于许多应用,包括3D重建,自动驾驶和视频监控。然而,广角图像包含违反针孔摄像机模型底层的假设的扭曲,导致对象失真,估计场景距离,面积和方向困难,以及防止在未造成的图像上使用现成的深层模型。下游计算机视觉任务。图像整流,旨在纠正这些扭曲,可以解决这些问题。本文从转换模型到整流方法的广角图像整流的全面调查进展。具体地,我们首先介绍了不同方法中使用的相机模型的详细描述和讨论。然后,我们总结了几种失真模型,包括径向失真和投影失真。接下来,我们审查了传统的基于几何图像整流方法和基于深度学习的方法,其中前者将失真参数估计作为优化问题,并且后者通过利用深神经网络的力量来将其作为回归问题。我们评估在公共数据集上最先进的方法的性能,并显示虽然两种方法都可以实现良好的结果,但这些方法仅适用于特定的相机型号和失真类型。我们还提供了强大的基线模型,并对合成数据集和真实世界广角图像进行了对不同失真模型的实证研究。最后,我们讨论了几个潜在的研究方向,预计将来进一步推进这一领域。
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Deep learning has been widely used in the perception (e.g., 3D object detection) of intelligent vehicle driving. Due to the beneficial Vehicle-to-Vehicle (V2V) communication, the deep learning based features from other agents can be shared to the ego vehicle so as to improve the perception of the ego vehicle. It is named as Cooperative Perception in the V2V research, whose algorithms have been dramatically advanced recently. However, all the existing cooperative perception algorithms assume the ideal V2V communication without considering the possible lossy shared features because of the Lossy Communication (LC) which is common in the complex real-world driving scenarios. In this paper, we first study the side effect (e.g., detection performance drop) by the lossy communication in the V2V Cooperative Perception, and then we propose a novel intermediate LC-aware feature fusion method to relieve the side effect of lossy communication by a LC-aware Repair Network (LCRN) and enhance the interaction between the ego vehicle and other vehicles by a specially designed V2V Attention Module (V2VAM) including intra-vehicle attention of ego vehicle and uncertainty-aware inter-vehicle attention. The extensive experiment on the public cooperative perception dataset OPV2V (based on digital-twin CARLA simulator) demonstrates that the proposed method is quite effective for the cooperative point cloud based 3D object detection under lossy V2V communication.
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The combination of artist-curated scans, and deep implicit functions (IF), is enabling the creation of detailed, clothed, 3D humans from images. However, existing methods are far from perfect. IF-based methods recover free-form geometry but produce disembodied limbs or degenerate shapes for unseen poses or clothes. To increase robustness for these cases, existing work uses an explicit parametric body model to constrain surface reconstruction, but this limits the recovery of free-form surfaces such as loose clothing that deviates from the body. What we want is a method that combines the best properties of implicit and explicit methods. To this end, we make two key observations: (1) current networks are better at inferring detailed 2D maps than full-3D surfaces, and (2) a parametric model can be seen as a "canvas" for stitching together detailed surface patches. ECON infers high-fidelity 3D humans even in loose clothes and challenging poses, while having realistic faces and fingers. This goes beyond previous methods. Quantitative, evaluation of the CAPE and Renderpeople datasets shows that ECON is more accurate than the state of the art. Perceptual studies also show that ECON's perceived realism is better by a large margin. Code and models are available for research purposes at https://xiuyuliang.cn/econ
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Computer vision applications in intelligent transportation systems (ITS) and autonomous driving (AD) have gravitated towards deep neural network architectures in recent years. While performance seems to be improving on benchmark datasets, many real-world challenges are yet to be adequately considered in research. This paper conducted an extensive literature review on the applications of computer vision in ITS and AD, and discusses challenges related to data, models, and complex urban environments. The data challenges are associated with the collection and labeling of training data and its relevance to real world conditions, bias inherent in datasets, the high volume of data needed to be processed, and privacy concerns. Deep learning (DL) models are commonly too complex for real-time processing on embedded hardware, lack explainability and generalizability, and are hard to test in real-world settings. Complex urban traffic environments have irregular lighting and occlusions, and surveillance cameras can be mounted at a variety of angles, gather dirt, shake in the wind, while the traffic conditions are highly heterogeneous, with violation of rules and complex interactions in crowded scenarios. Some representative applications that suffer from these problems are traffic flow estimation, congestion detection, autonomous driving perception, vehicle interaction, and edge computing for practical deployment. The possible ways of dealing with the challenges are also explored while prioritizing practical deployment.
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大多数现有的语义分割方法都以图像级类标签作为监督,高度依赖于从标准分类网络生成的初始类激活图(CAM)。在本文中,提出了一种新颖的“渐进贴片学习”方法,以改善分类的局部细节提取,从而更好地覆盖整个对象的凸轮,而不仅仅是在常规分类模型中获得的CAM中的最歧视区域。 “补丁学习”将特征映射破坏成贴片,并在最终聚合之前并行独立处理每个本地贴片。这样的机制强迫网络从分散的歧视性本地部分中找到弱信息,从而提高了本地细节的敏感性。 “渐进的补丁学习”进一步将特征破坏和补丁学习扩展到多层粒度。与多阶段优化策略合作,这种“渐进的补丁学习”机制隐式地为模型提供了跨不同位置粒状性的特征提取能力。作为隐式多粒性渐进式融合方法的替代方案,我们还提出了一种明确的方法,以同时将单个模型中不同粒度的特征融合,从而进一步增强了完整对象覆盖的凸轮质量。我们提出的方法在Pascal VOC 2012数据集上取得了出色的性能,例如,测试集中有69.6 $%miou),它超过了大多数现有的弱监督语义细分方法。代码将在此处公开提供,https://github.com/tyroneli/ppl_wsss。
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生成精确的类感知的伪基真实,也就是类激活图(CAM),对于弱监督的语义分割至关重要。原始CAM方法通常会产生不完整和不准确的定位图。为了解决这个问题,本文提出了基于可变形卷积中的偏移学习的扩展和收缩方案,以依次改善两个各个阶段中定位对象的回忆和精度。在扩展阶段,在可变形卷积层中的偏移学习分支,称为“扩展采样器”,寻求采样越来越小的判别对象区域,这是由逆监督信号驱动的,从而最大程度地提高了图像级分类损失。然后在收缩阶段逐渐将位置更完整的物体逐渐缩小到最终对象区域。在收缩阶段,引入了另一个可变形卷积层的偏移学习分支,称为“收缩采样器”,以排除在扩展阶段参加的假积极背景区域,以提高定位图的精度。我们在Pascal VOC 2012和MS Coco 2014上进行了各种实验,以很好地证明了我们方法比其他最先进的方法对弱监督语义分割的优越性。代码将在此处公开提供,https://github.com/tyroneli/esol_wsss。
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SMPL(SMPL)的参数3D身体模型仅代表最小衣服的人,并且很难扩展到衣服,因为它们具有固定的网格拓扑和分辨率。为了解决这些局限性,最近的工作使用隐式表面或点云来建模衣服。虽然不受拓扑的限制,但这种方法仍然很难为偏离身体的偏离的衣服建模,例如裙子和连衣裙。这是因为他们依靠身体来通过将衣服表面放置为参考形状。不幸的是,当衣服远离身体时,这个过程的定义很差。此外,他们使用线性混合剥皮来摆姿势,并将皮肤重量与下面的身体部位绑在一起。相比之下,我们在没有规范化的情况下对局部坐标空间中的衣服变形进行了建模。我们还放松皮肤重量以使多个身体部位影响表面。具体而言,我们用粗糙的阶段扩展了基于点的方法,该方法用学习的姿势独立的“粗大形状”代替了规范化,该方法可以捕获裙子(如裙子)的粗糙表面几何形状。然后,我们使用一个网络来完善该网络,该网络会渗透到粗糙表示中的线性混合剥皮权重和姿势依赖的位移。该方法适合符合身体并偏离身体的服装。我们通过从示例中学习特定于人的化身,然后展示如何以新的姿势和动作来展示它们的有用性。我们还表明,该方法可以直接从原始扫描中学习缺少数据,从而大大简化了创建逼真的化身的过程。代码可用于研究目的,可在{\ small \ url {https://qianlim.github.io/skirt}}中使用。
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带有嘈杂标签的训练深神经网络(DNN)实际上是具有挑战性的,因为不准确的标签严重降低了DNN的概括能力。以前的努力倾向于通过识别带有粗糙的小损失标准来减轻嘈杂标签的干扰的嘈杂数据来处理统一的denoising流中的零件或完整数据,而忽略了嘈杂样本的困难是不同的,因此是刚性和统一的。数据选择管道无法很好地解决此问题。在本文中,我们首先提出了一种称为CREMA的粗到精细的稳健学习方法,以分裂和串扰的方式处理嘈杂的数据。在粗糙水平中,干净和嘈杂的集合首先从统计意义上就可信度分开。由于实际上不可能正确对所有嘈杂样本进行分类,因此我们通过对每个样本的可信度进行建模来进一步处理它们。具体而言,对于清洁集,我们故意设计了一种基于内存的调制方案,以动态调整每个样本在训练过程中的历史可信度顺序方面的贡献,从而减轻了错误地分组为清洁集中的嘈杂样本的效果。同时,对于分类为嘈杂集的样品,提出了选择性标签更新策略,以纠正嘈杂的标签,同时减轻校正错误的问题。广泛的实验是基于不同方式的基准,包括图像分类(CIFAR,Clothing1M等)和文本识别(IMDB),具有合成或自然语义噪声,表明CREMA的优势和普遍性。
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自我监督的学习旨在消除图形表示学习中昂贵注释的需求,在该学习中,图形对比度学习(GCL)接受了包含数据数据对的自学信号培训。这些数据数据对是通过在原始图上使用随机函数的增强作用生成的。我们认为,根据下游任务,某些功能比其他功能更重要,并且统一应用随机功能会破坏影响力的特征,从而导致精度降低。为了解决此问题,我们介绍了一种基于功能的自适应增强(FEBAA)方法,该方法识别并保留了潜在的影响力并破坏其余的功能。我们实现FEBAA作为插头和播放层,并将其与最先进的深图对比度学习(GRACE)和自举图形潜伏期(BGRL)一起使用。我们在八个图表学习的基准数据集上成功提高了Grace和BGRL的准确性。
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视频实例细分(VIS)是一项在视频中同时需要分类,细分和实例关联的任务。最近的VIS方法依靠复杂的管道来实现此目标,包括与ROI相关的操作或3D卷积。相比之下,我们通过添加额外的跟踪头提出了基于实例分割方法Condinst的简单有效的单阶段VIS框架。为了提高实例关联精度,提出了一种新型的双向时空对比度学习策略,用于跟踪跨帧的嵌入。此外,利用实例的时间一致性方案来产生时间连贯的结果。在YouTube-VIS-2019,YouTube-Vis-2021和OVIS-2021数据集上进行的实验验证了所提出方法的有效性和效率。我们希望所提出的框架可以作为许多其他实例级视频关联任务的简单而强大的替代方案。
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