This letter focuses on the task of Multi-Target Multi-Camera vehicle tracking. We propose to associate single-camera trajectories into multi-camera global trajectories by training a Graph Convolutional Network. Our approach simultaneously processes all cameras providing a global solution, and it is also robust to large cameras unsynchronizations. Furthermore, we design a new loss function to deal with class imbalance. Our proposal outperforms the related work showing better generalization and without requiring ad-hoc manual annotations or thresholds, unlike compared approaches.

近年来，多个对象跟踪引起了研究人员的极大兴趣，它已成为计算机视觉中的趋势问题之一，尤其是随着自动驾驶的最新发展。 MOT是针对不同问题的关键视觉任务之一，例如拥挤的场景中的闭塞，相似的外观，小物体检测难度，ID切换等，以应对这些挑战，因为研究人员试图利用变压器的注意力机制，与田径的相互关系，与田径的相互关系，图形卷积神经网络，与暹罗网络不同帧中对象的外观相似性，他们还尝试了基于IOU匹配的CNN网络，使用LSTM的运动预测。为了将这些零散的技术在雨伞下采用，我们研究了过去三年发表的一百多篇论文，并试图提取近代研究人员更关注的技术来解决MOT的问题。我们已经征集了许多应用，可能性以及MOT如何与现实生活有关。我们的评论试图展示研究人员使用过时的技术的不同观点，并为潜在的研究人员提供了一些未来的方向。此外，我们在这篇评论中包括了流行的基准数据集和指标。

多目标多摄像机跟踪（MTMCT）中的数据关联通常从重新识别（RE-ID）特征距离直接估计亲和力。但是，我们认为它可能不是最佳选择，因为匹配范围与MTMCT问题之间的匹配范围差异。重新ID系统专注于全局匹配，从而从所有相机和常规检索目标。相反，跟踪中的数据关联是一个本地匹配问题，因为其候选者仅来自相邻位置和时间框架。在本文中，我们设计实验，以验证全局重新ID功能距离和本地匹配在跟踪中的本地匹配之间的这种错误，并提出了一种简单但有效的方法来适应MTMCT中的相应匹配范围。我们不是尝试处理所有外观变化，而不是在数据关联期间专门调整关联度量来专门化。为此，我们介绍了一种新的数据采样方案，其中包含用于跟踪中的数据关联的时间窗口。自适应亲和模块最小化不匹配，对全局重新ID距离具有显着的改进，并在CityFlow和DukemTMC数据集中生成竞争性能。

Tracking objects over long videos effectively means solving a spectrum of problems, from short-term association for un-occluded objects to long-term association for objects that are occluded and then reappear in the scene. Methods tackling these two tasks are often disjoint and crafted for specific scenarios, and top-performing approaches are often a mix of techniques, which yields engineering-heavy solutions that lack generality. In this work, we question the need for hybrid approaches and introduce SUSHI, a unified and scalable multi-object tracker. Our approach processes long clips by splitting them into a hierarchy of subclips, which enables high scalability. We leverage graph neural networks to process all levels of the hierarchy, which makes our model unified across temporal scales and highly general. As a result, we obtain significant improvements over state-of-the-art on four diverse datasets. Our code and models will be made available.

We introduce a novel framework to track multiple objects in overhead camera videos for airport checkpoint security scenarios where targets correspond to passengers and their baggage items. We propose a Self-Supervised Learning (SSL) technique to provide the model information about instance segmentation uncertainty from overhead images. Our SSL approach improves object detection by employing a test-time data augmentation and a regression-based, rotation-invariant pseudo-label refinement technique. Our pseudo-label generation method provides multiple geometrically-transformed images as inputs to a Convolutional Neural Network (CNN), regresses the augmented detections generated by the network to reduce localization errors, and then clusters them using the mean-shift algorithm. The self-supervised detector model is used in a single-camera tracking algorithm to generate temporal identifiers for the targets. Our method also incorporates a multi-view trajectory association mechanism to maintain consistent temporal identifiers as passengers travel across camera views. An evaluation of detection, tracking, and association performances on videos obtained from multiple overhead cameras in a realistic airport checkpoint environment demonstrates the effectiveness of the proposed approach. Our results show that self-supervision improves object detection accuracy by up to $42\%$ without increasing the inference time of the model. Our multi-camera association method achieves up to $89\%$ multi-object tracking accuracy with an average computation time of less than $15$ ms.

图提供了一种自然的方式来制定多个对象跟踪（MOT）和多个对象跟踪和分割（MOTS），逐个检测范式中。但是，他们还引入了学习方法的主要挑战，因为定义可以在这种结构化领域运行的模型并不是微不足道的。在这项工作中，我们利用MOT的经典网络流程公式来定义基于消息传递网络（MPN）的完全微分框架。通过直接在图形域上操作，我们的方法可以在整个检测和利用上下文特征上全球推理。然后，它共同预测了数据关联问题的最终解决方案和场景中所有对象的分割掩码，同时利用这两个任务之间的协同作用。我们在几个公开可用的数据集中获得跟踪和细分的最新结果。我们的代码可在github.com/ocetintas/mpntrackseg上找到。

To track the 3D locations and trajectories of the other traffic participants at any given time, modern autonomous vehicles are equipped with multiple cameras that cover the vehicle's full surroundings. Yet, camera-based 3D object tracking methods prioritize optimizing the single-camera setup and resort to post-hoc fusion in a multi-camera setup. In this paper, we propose a method for panoramic 3D object tracking, called CC-3DT, that associates and models object trajectories both temporally and across views, and improves the overall tracking consistency. In particular, our method fuses 3D detections from multiple cameras before association, reducing identity switches significantly and improving motion modeling. Our experiments on large-scale driving datasets show that fusion before association leads to a large margin of improvement over post-hoc fusion. We set a new state-of-the-art with 12.6% improvement in average multi-object tracking accuracy (AMOTA) among all camera-based methods on the competitive NuScenes 3D tracking benchmark, outperforming previously published methods by 6.5% in AMOTA with the same 3D detector.

我们提出了一种新型的图形神经网络（GNN）方法，用于高通量显微镜视频中的细胞跟踪。通过将整个延时序列建模为直接图，其中细胞实例由其节点及其边缘表示，我们通过查找图中的最大路径来提取整个细胞轨迹。这是由纳入端到端深度学习框架中的几个关键贡献来完成的。我们利用深度度量学习算法来提取细胞特征向量，以区分不同生物细胞的实例并组装相同的细胞实例。我们引入了一种新的GNN块类型，该类型可以对节点和边缘特征向量进行相互更新，从而促进基础消息传递过程。消息传递概念的范围由GNN块的数量确定，这是至关重要的，因为它可以在连续的框架中实现节点和边缘之间的“节点和边缘”之间的“流动”。最后，我们解决了边缘分类问题，并使用已确定的活动边缘来构建单元格的轨道和谱系树。我们通过将其应用于不同细胞类型，成像设置和实验条件的2D和3D数据集，来证明所提出的细胞跟踪方法的强度。我们表明，我们的框架在大多数评估的数据集上都优于当前最新方法。该代码可在我们的存储库中获得：https：//github.com/talbenha/cell-tracker-gnn。

Existing Multiple Object Tracking (MOT) methods design complex architectures for better tracking performance. However, without a proper organization of input information, they still fail to perform tracking robustly and suffer from frequent identity switches. In this paper, we propose two novel methods together with a simple online Message Passing Network (MPN) to address these limitations. First, we explore different integration methods for the graph node and edge embeddings and put forward a new IoU (Intersection over Union) guided function, which improves long term tracking and handles identity switches. Second, we introduce a hierarchical sampling strategy to construct sparser graphs which allows to focus the training on more difficult samples. Experimental results demonstrate that a simple online MPN with these two contributions can perform better than many state-of-the-art methods. In addition, our association method generalizes well and can also improve the results of private detection based methods.

多摄像机多对象跟踪目前在计算机视野中引起了注意力，因为它在现实世界应用中的卓越性能，如具有拥挤场景或巨大空间的视频监控。在这项工作中，我们提出了一种基于空间升降的多乳制型配方的数学上优雅的多摄像多对象跟踪方法。我们的模型利用单摄像头跟踪器产生的最先进的TOOTWLET作为提案。由于这些Tracklet可能包含ID-Switch错误，因此我们通过从3D几何投影获得的新型预簇来完善它们。因此，我们派生了更好的跟踪图，没有ID交换机，更精确的数据关联阶段的亲和力成本。然后通过求解全局提升的多乳制型制剂，将轨迹与多摄像机轨迹匹配，该组件包含位于同一相机和相互相机间的Tracklet上的短路和远程时间交互。在Wildtrack DataSet的实验结果是近乎完美的结果，在校园上表现出最先进的追踪器，同时在PETS-09数据集上处于校准状态。我们将在接受纸质时进行我们的实施。

跟踪和识别玩家是基于计算机视觉冰球分析的基本步骤。跟踪生成的数据用于许多其他下游任务，例如游戏事件检测和游戏策略分析。播放器跟踪和识别是一个具有挑战性的问题，因为与行人相比，曲棍球运动员的运动是快节奏和非线性的。还有显着的摄像头淘气和放大曲棍球广播视频。识别冰球中的玩家是挑战，因为同一团队的球员几乎相同，泽西号码是玩家之间唯一的鉴别因素。本文介绍了一种用于跟踪和识别广播NHL曲棍球视频中的玩家的自动化系统。该系统由三个组件（1）播放器跟踪组成，（2）团队识别和（3）播放器识别。由于没有公开可用的数据集，用于培训三个组件的数据集手动注释。利用艺术跟踪算法的状态来执行播放器跟踪，从而获得多目标跟踪精度（MOTA）得分为94.5％。对于团队识别，Away-Team Jerseys被分组为单一课程，并根据他们的泽西颜色在课堂上分组。然后在团队识别数据集上培训卷积神经网络。团队识别网络在测试集中获得97％的准确性。引入了一种新颖的播放器识别模型，其利用时间一维卷积网络来识别来自玩家边界框序列的玩家。播放器识别模型进一步利用了可用的NHL游戏名册数据，以获得83％的玩家识别精度。

大多数（3D）多对象跟踪方法依赖于数据关联的外观提示。相比之下，我们研究了仅通过编码3D空间中对象之间的几何关系作为数据驱动数据关联的线索，我们才能达到多远。我们将3D检测编码为图中的节点，其中对象之间的空间和时间成对关系是通过图边缘上的局部极性坐标编码的。这种表示使我们的几何关系不变到全球变换和平滑的轨迹变化，尤其是在非全面运动下。这使我们的图形神经网络可以学会有效地编码时间和空间交互，并充分利用上下文和运动提示，以通过将数据关联作为边缘分类来获得最终场景解释。我们在Nuscenes数据集上建立了一个新的最先进的方法，更重要的是，我们的方法在不同位置（波士顿，新加坡，Karlsruhe）和数据集（Nuscenes和Kitti）中跨越了我们的方法。

基于时空的图（STMAP）方法显示出为车辆轨迹重建处理高角度视频的巨大潜力，可以满足各种数据驱动的建模和模仿学习应用的需求。在本文中，我们开发了时空深嵌入（STDE）模型，该模型在像素和实例水平上施加了平等约束，以生成用于STMAP上车辆条纹分割的实例感知嵌入。在像素级别上，每个像素在不同范围的8-邻居像素进行编码，随后使用该编码来指导神经网络学习嵌入机制。在实例级别上，歧视性损耗函数被设计为将属于同一实例的像素更接近，并将不同实例的平均值分开。然后，通过静脉 - 沃特算法算法优化时空亲和力的输出，以获得最终的聚类结果。基于分割指标，我们的模型优于其他五个用于STMAP处理的基线，并在阴影，静态噪声和重叠的影响下显示出稳健性。该设计的模型用于处理所有公共NGSIM US-101视频，以生成完整的车辆轨迹，表明具有良好的可扩展性和适应性。最后但并非最不重要的一点是，讨论了带有STDE和未来方向的扫描线方法的优势。代码，STMAP数据集和视频轨迹在在线存储库中公开可用。 github链接：shorturl.at/jklt0。

宽阔的区域运动图像（瓦米）产生具有大量极小物体的高分辨率图像。目标物体在连续帧中具有大的空间位移。令人讨厌的图像的这种性质使对象跟踪和检测具有挑战性。在本文中，我们介绍了我们基于深度神经网络的组合对象检测和跟踪模型，即热图网络（HM-Net）。 HM-Net明显快于最先进的帧差异和基于背景减法的方法，而不会影响检测和跟踪性能。 HM-Net遵循基于对象的联合检测和跟踪范式。简单的热图的预测支持无限数量的同时检测。所提出的方法使用来自前一帧的两个连续帧和物体检测热图作为输入，这有助于帧之间的HM-Net监视器时空变化并跟踪先前预测的对象。尽管重复使用先前的物体检测热图作为基于生命的反馈的存储器元件，但它可能导致假阳性检测的意外浪涌。为了增加对误报和消除低置信度检测的方法的稳健性，HM-Net采用新的反馈滤波器和高级数据增强。 HM-Net优于最先进的WAMI移动对象检测和跟踪WPAFB数据集的跟踪方法，其96.2％F1和94.4％地图检测分数，同时在同一数据集上实现61.8％的地图跟踪分数。这种性能对应于F1，6.1％的地图分数的增长率为2.1％，而在追踪最先进的地图分数的地图分数为9.5％。

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.

The problem of tracking multiple objects in a video sequence poses several challenging tasks. For tracking-bydetection, these include object re-identification, motion prediction and dealing with occlusions. We present a tracker (without bells and whistles) that accomplishes tracking without specifically targeting any of these tasks, in particular, we perform no training or optimization on tracking data. To this end, we exploit the bounding box regression of an object detector to predict the position of an object in the next frame, thereby converting a detector into a Tracktor. We demonstrate the potential of Tracktor and provide a new state-of-the-art on three multi-object tracking benchmarks by extending it with a straightforward re-identification and camera motion compensation.We then perform an analysis on the performance and failure cases of several state-of-the-art tracking methods in comparison to our Tracktor. Surprisingly, none of the dedicated tracking methods are considerably better in dealing with complex tracking scenarios, namely, small and occluded objects or missing detections. However, our approach tackles most of the easy tracking scenarios. Therefore, we motivate our approach as a new tracking paradigm and point out promising future research directions. Overall, Tracktor yields superior tracking performance than any current tracking method and our analysis exposes remaining and unsolved tracking challenges to inspire future research directions.

在这项工作中，我们提出了一个具有结构性图形的新型不确定性感知对象检测框架，其中节点和边缘分别用对象及其空间语义相似性表示。具体而言，我们旨在考虑对象之间的关系，以有效地将它们背景化。为了实现这一目标，我们首先检测对象，然后测量其语义和空间距离以构建对象图，然后由图形神经网络（GNN）表示，用于完善对象的视觉CNN特征。但是，精炼CNN功能和每个对象的检测结果效率低下，可能不需要，因为其中包括不确定性低的正确预测。因此，我们建议通过将表示形式从某些对象（源）转移到有向图上的不确定对象（目标）来处理不确定的对象，而且还仅在对象上改善CNN功能，因为对象被认为是不确定的，其代表性输出来自GNN。此外，我们通过在不确定的物体上给予更大的权重来计算训练损失，以专注于改善不确定的对象预测，同时保持某些对象的高性能。我们将模型称为对象检测（UAGDET）的不确定性感知图网络。然后，我们在实验中验证了我们的大规模空中图像数据集，即DOTA，该数据集由大量对象组成，这些对象在图像中具有很小至大的对象，在该图像上，我们的对象可以改善现有对象检测网络的性能。

在监控和搜索和救援应用程序中，重要的是在低端设备上实时执行多目标跟踪（MOT）。今天的MOT解决方案采用深度神经网络，往往具有高计算复杂性。识别帧大小对跟踪性能的影响，我们提出了深度，一种模型不可知框架尺寸选择方法，可在现有的全卷积网络基跟踪器之上进行操作，以加速跟踪吞吐量。在培训阶段，我们将可检测性分数纳入单次跟踪器架构，使得DeepScale以自我监督的方式学习不同帧大小的表示估计。在推理期间，它可以根据基于用户控制参数根据视觉内容的复杂性来调整帧大小。为了利用边缘服务器上的计算资源，我们提出了两个计算分区模式，即仅使用自适应帧大小传输和边缘服务器辅助跟踪仅适用于MOT，即边缘服务器。 MOT数据集的广泛实验和基准测试证明了深度的有效性和灵活性。与最先进的追踪器相比，DeepScale ++，DeepScale的变种实现1.57倍加速，仅在一个配置中的MOT15数据集上跟踪准确性。我们已经实现和评估了DeepScale ++，以及由NVIDIA JETSON TX2板和GPU服务器组成的小型测试平台上所提出的计算分区方案。实验显示与仅服务器或智能相机的解决方案相比跟踪性能和延迟之间的非琐碎权衡。

Measuring growth rates of apple fruitlets is important because it allows apple growers to determine when to apply chemical thinners to their crops to optimize yield. The current practice of obtaining growth rates involves using calipers to record sizes of fruitlets across multiple days. Due to the number of fruitlets needed to be sized, this method is laborious, time-consuming, and prone to human error. In this paper, we present a computer vision approach to measure the sizes and growth rates of apple fruitlets. With images collected by a hand-held stereo camera, our system detects, segments, and fits ellipses to fruitlets to measure their diameters. To measure growth rates, we utilize an Attentional Graph Neural Network to associate fruitlets across different days. We provide quantitative results on data collected in an apple orchard, and demonstrate that our system is able to predict abscise rates within 3% of the current method with a 7 times improvement in speed, while requiring significantly less manual effort. Moreover, we provide results on images captured by a robotic system in the field, and discuss the next steps to make the process fully autonomous.

Deep learning has revolutionized many machine learning tasks in recent years, ranging from image classification and video processing to speech recognition and natural language understanding. The data in these tasks are typically represented in the Euclidean space. However, there is an increasing number of applications where data are generated from non-Euclidean domains and are represented as graphs with complex relationships and interdependency between objects. The complexity of graph data has imposed significant challenges on existing machine learning algorithms. Recently, many studies on extending deep learning approaches for graph data have emerged. In this survey, we provide a comprehensive overview of graph neural networks (GNNs) in data mining and machine learning fields. We propose a new taxonomy to divide the state-of-the-art graph neural networks into four categories, namely recurrent graph neural networks, convolutional graph neural networks, graph autoencoders, and spatial-temporal graph neural networks. We further discuss the applications of graph neural networks across various domains and summarize the open source codes, benchmark data sets, and model evaluation of graph neural networks. Finally, we propose potential research directions in this rapidly growing field.