基于模型和区域相关融合的鲁棒跟踪算法

提出了一种模型部分匹配的相似度量方法,利用匹配的完整度、归一化的匹配点相对于模型的偏移量期望和方差的加权和作为相似性度量。在此基础上建立模型匹配算法,利用模型匹配和区域相关融合的方法进行目标跟踪。算法能够在摄像机静止和运动的情况下进行稳定的跟踪,能够适应目标的部分遮挡、光照和姿态的变化。利用参数化的模型能够在复杂的背景环境中实现实时的多目标跟踪。     

利用部分观测跟踪被遮挡的目标

提出了一个在单个固定摄像机下进行多目标跟踪的方法.利用亮度和色度混合模型和卡尔曼滤波器来检测跟踪目标,为了利于预测和解释被遮挡的物体,建立了场景的模型.在遮挡的情况下,和传统的盲跟踪不同,本文中的目标状态是由可用的部分观测来估计的.对目标的观测取决于预测、前景观测和场景模型.这使得本文算法在定性或定量的分析下都表现出更加鲁棒的性能.     

运动摄像机下多目标检测与跟踪

针对摄像机运动情况下多目标的检测与跟踪问题,提出一种将Global K均值与模板匹配相结合的方法.利用六参数仿射模型得到摄像机运动参数,对图像进行全局运动补偿,用GlobalK均值算法对前景点进行循环聚类,判断目标数目并进行跟踪,通过对目标区域进行模板匹配使跟踪结果更准确.实验结果表明,该方法能够在运动摄像机下稳定、实时地跟踪多个目标,对发生形变的目标基本也能稳定跟踪.     

Multi-object detection and tracking by stereo vision

This paper presents a new stereo vision-based model for multi-object detection and tracking in surveillance systems. Unlike most existing monocular camera-based systems, a stereo vision system is constructed in our model to overcome the problems of illumination variation, shadow interference, and object occlusion. In each frame, a sparse set of feature points are identified in the camera coordinate system, and then projected to the 2D ground plane. A kernel-based clustering algorithm is proposed to group the projected points according to their height values and locations on the plane. By producing clusters, the number, position, and orientation of objects in the surveillance scene can be determined for online multi-object detection and tracking. Experiments on both indoor and outdoor applications with complex scenes show the advantages of the proposed system.     

基于卡尔曼滤波的多目标跟踪方法

针对视频多目标跟踪中由于目标间的遮挡、交错或目标漂移而导致跟踪失败的情况,提出一种基于卡尔曼滤波以及空间颜色直方图的遮挡预测跟踪算法。利用空间颜色直方图对目标进行建模,可以对不同目标进行区分进而在目标之间出现交错或目标漂移时仍能跟踪到目标。通过卡尔曼滤波算法可以 预测 目标的状态,对预测位置之间存在交错的目标进行遮挡标记,以便在下一帧中仍然可以跟踪到被遮挡的目标。采用2D MOT 2015数据集进行实验,跟踪的平均精度达到了34.1%。实验结果表明,所提方法对多目标跟踪的效果有所提高。     

基于SIFT特征的抗遮挡目标跟踪算法

针对多目标跟踪过程中目标易丢失的问题,提出一种基于尺度不变特征变换(SIFT)特征的多目标跟踪算法。利用SIFT特征集,通过设置目标特征留存优先级,实时更新特征集,保存目标近几帧的稳定特征。对于半遮挡导致的物体丢失现象,提出一种根据匹配特征位置关系进行目标分离的方法,可有效标定遮挡发生时的各个目标。该算法无需目标的先验信息,通过留存优先级即可较稳定地跟踪多个目标。实验结果证明其对目标遮挡、尺度变化及形变具有较好的容错性和跟踪鲁棒性。     

一种基于Multi-Egocentric视频运动轨迹重建的多目标跟踪算法

Egocentric视频具有目标运动剧烈、遮挡频繁、目标尺度差异明显及视角时变性强的特点，给目标跟踪任务造成了极大的困难。本文从重建不同视角Egocentric视频中各目标的运动轨迹出发，提出一种基于Multi-Egocentric视频运动轨迹重建的多目标跟踪算法，该方法基于多视角同步帧之间的单应性约束解决目标遮挡和丢失问题，然后根据多视角目标空间位置约束关系通过轨迹重建进一步优化目标定位，并采用卡尔曼滤波构建目标运动模型优化目标运动轨迹，在BJMOT、EPLF-campus4数据集上的对比实验验证了本文算法在解决Multi-Egocentric视频多目标跟踪轨迹不连续问题的有效性。     

自适应在线判别外观学习的分层关联多目标跟踪

目的 复杂场景下目标频繁且长时间的遮挡、跟踪目标外观相似引起身份转换等问题给多目标跟踪带来许多挑战。针对多目标跟踪在复杂场景中因长时间遮挡引起身份转换和轨迹分段的问题,提出一种基于自适应在线判别外观学习的分层关联多目标跟踪算法。方法 利用轨迹置信度将多目标跟踪分为局部关联和全局关联两个层次。在局部关联中,置信度高的可靠轨迹利用外观、位置-大小相似度与当前帧检测点进行关联;在全局关联中,置信度低的不可靠轨迹引入运动模型和有效关联范围进一步关联分段的轨迹。在提取目标外观特征时引入增量线性可判别分析方法以解决身份转换问题,依据新增样本与目标样本均值的外观特征差异自适应地更新目标外观模型。结果 在公开数据集2D MOT2015中的PETS09-S2L1、TUD-Stadmitte、Town-Center 3个数据集中与当前10种多目标跟踪算法进行比较,该方法对各个数据集身份转换和轨迹分段都有减少,其中在Town-Center数据集中,身份转换减少了60个,轨迹分段减少了84个,跟踪准确度提高了5.2%以上。结论 本文多目标跟踪方法,能够在复杂场景中稳定有效地实现多目标跟踪,减少轨迹分段现象,其中引入的在线线性可判别外观学习对遮挡产生的身份转换具有良好的解决效果。     

基于运动检测与运动搜索的多目标跟踪

提出一种新的单摄像机多目标跟踪方法,采用全局背景减法得到当前帧所有运动区域,利用kalman滤波器及局部背景减法得到已跟踪目标在当前帧的预测区域,根据全局减法运动区域及预测区域的位置及大小来判断是否有遮挡发生,并用不同匹配方法进行目标跟踪。实验表明,该方法能有效提高单摄像机跟踪对目标合并、遮挡等问题的处理能力。     

Distributed wide-area multi-object tracking with non-overlapping camera views

We present a distributed system for wide-area multi-object tracking across disjoint camera views. Every camera in the system performs multi-object tracking, and keeps its own trackers and trajectories. The data from multiple features are exchanged between adjacent cameras for object matching. We employ a probabilistic Petri Net-based approach to account for the uncertainties of the vision algorithms (such as unreliable background subtraction, and tracking failure) and to incorporate the available domain knowledge. We combine appearance features of objects as well as the travel-time evidence for target matching and consistent labeling across disjoint camera views. 3D color histogram, histogram of oriented gradients, local binary patterns, object size and aspect ratio are used as the appearance features. The distribution of the travel time is modeled by a Gaussian mixture model. Multiple features are combined by the weights, which are assigned based on the reliability of the features. By incorporating the domain knowledge about the camera configurations and the information about the received packets from other cameras, certain transitions are fired in the probabilistic Petri net. The system is trained to learn different parameters of the matching process, and updated online. We first present wide-area tracking of vehicles, where we used three non-overlapping cameras. The first and the third cameras are approximately 150 m apart from each other with two intersections in the blind region. We also present an example of applying our method to a people-tracking scenario. The results show the success of the proposed method. A comparison between our work and related work is also presented.     

基于基础颜色特征的自适应尺度的多目标跟踪算法

在多目标跟踪领域,多个相似目标间相互遮挡时,易产生误跟踪、漏跟踪等问题。针对上述问题,通过引入语言学中的基础颜色及自适应尺度因子来解决。采用颜色命名过程及主成分分析法,提取目标基础颜色特征,准确区分相似目标;同时引入自适应尺度因子,自动改变目标尺度,减少因尺度变化而引入的干扰信息,增强目标外观模型的鲁棒性。基于以上两点,在Structure Preserving Object Tracking（SPOT）算法基础上,提出了Basic Color Adaptive Scale SPOT（CSSPOT）算法。在对比实验中,CSSPOT算法在跟踪准确率及计算时间这两方面较原算法均有所提升,充分说明了基础颜色特征及自适应尺度因子的正确性及有效性。     

基于多重信息融合与轨迹关联修正的多目标跟踪方法

一阶段多目标跟踪框架由于可以有效提升算法跟踪效率而备受关注,然而该框架在提升效率的同时忽略了检测与关联任务间信息的交互,且目标遮挡的频发会导致轨迹碎片的增加,从而影响跟踪效果.针对这些问题,提出基于多重信息融合与轨迹关联修正的多目标跟踪方法.通过无锚一阶段主干网络,在检测器上另外建立跟踪分支预测跟踪偏移量和嵌入特征信息;设计中和匹配关联模块优化跨帧特征匹配方式,协调检测与关联任务,提升两任务间信息交互能力;采用多重信息融合模块,对时空多层次特征进行融合以获得更加丰富的特征信息;提出轨迹关联修正网络处理因遮挡造成的轨迹碎片,通过改进数据关联方式评估碎片与检测低分目标关系,尝试找回遮挡目标轨迹;将提出的算法在MOT16和MOT17数据集上进行评估,并与其他优异的算法定量比较.通过分析实验结果可以发现,所提出的方法能有效缓解关键性问题,提升算法整体性能.     

Applications for a people detection and tracking algorithm using a time-of-flight camera

This paper outlines a method and applications for detection and tracking of people in depth images, acquired with a low-resolution Time-of-Flight (ToF) camera. This depth sensor is placed perpendicular to the ground in order to provide distance information from a top-view position. Usage of intrinsic and extrinsic camera parameters allows estimation of a ground plane and comparison to the measured distances of the ToF sensor in every pixel. Differences to the expected ground plane define foreground information, that is subsequently combined to associated regions. These regions of interest (ROI) are analyzed to distinguish persons from other objects by using a matched filter that is applied the height segmented depth information of each of these regions. The proposed method separates crowds into individuals and facilitates a multi-object tracking system based on Kalman filtering. Furthermore, we present several applications for the proposed method. Experiments with different crowding situations - from very low to very high density - and different heights of camera placements have proven the applicability and practicability of the system.     

基于改进的Transformer加Anchor-free网络的多目标跟踪算法

近年来,基于Anchor-free的多目标跟踪算法以其精度高、速度快、超参数少的特点被广泛研究.但是,实际场景中的目标遮挡使得此类算法仍然面临挑战,这类算法会对遮挡后重新出现的目标的身份信息进行错误切换.针对以上问题,提出了一种基于改进的Transformer加Anchor-free网络的多目标跟踪算法(Transfo...     

一种基于运动信息的多目标跟踪方法研究

为解决多目标跟踪中的遮挡问题,提出一种基于目标运动信息的方法。采用混合高斯模型结合背景差法获取初始运动信息,根据目标短时间内状态的稳定性,对其进行预测,再结合视觉特征达到精确跟踪。由于使用速度和视觉特征信息对目标单独跟踪,从而巧妙地避免遮挡的处理。实验结果表明,该方法实时有效,同时对遮挡问题的处理也有较好的效果。     

A novel multi-object detection method in complex scene using synthetic aperture imaging

This paper proposes a novel multi-object detection method using multiple cameras. Unlike conventional multi-camera object detection methods, our method detects multiple objects using a linear camera array. The array can stream different views of the environment and can be easily reconfigured for a scene compared with the overhead surround configuration. Using the proposed method, the synthesized results can provide not only views of significantly occluded objects but also the ability of focusing on the target while blurring objects that are not of interest. Our method does not need to reconstruct the 3D structure of the scene, can accommodate dynamic background, is able to detect objects at any depth using a new synthetic aperture imaging method based on a simple shift transformation, and can see through occluders. The experimental results show that the proposed method has a good performance and can synthesize objects located within any designated depth interval with much better clarity than that using an existing method. To our best knowledge, it is the first time that such a method using synthetic aperture imaging has been proposed and developed for multi-object detection in a complex scene with a significant occlusion at different depths.     

加强重识别的行人多目标跟踪算法

在多目标跟踪任务中,重识别（re-identification,Re-ID）效果通常依赖于检测性能的好坏,检测偏差会导致ReID特征模糊,从而降低重识别精度。特别是在尺度变化和频繁遮挡等复杂场景下,Re-ID鲁棒性不高,多目标跟踪效果较差。针对该问题,提出一种加强重识别的行人多目标跟踪算法。该算法以CenterNet为检测器,通过预测目标中心点热力图来检测目标位置,并设计检测偏差损失加强对预测热力图响应值的约束,以缓解因检测不准确导致的ReID特征模糊问题。为提高Re-ID鲁棒性,提出Re-ID可学习特征动态扩充策略。该策略通过自适应扩充目标中心的Re-ID可学习特征来提高特征质量,并减小Re-ID对中心点检测精度的依赖。在MOT16和MOT17测试集上进行验证,结果表明,算法能有效提升Re-ID性能,与主流算法相比具有更好的跟踪效果,且兼顾了实时性,达到25.6 FPS。     

室内遮挡多人跟踪

提出一种在固定摄像机室内遮挡条件下的多人跟踪算法,包括基于改进的独立成分分析模型的运动前景分割、数据关联与合并检测和基于贪心搜索的遮挡目标定位三部分。将方法应用于室内多目标遮挡,结果表明该算法对发生遮挡的目标数量、目标被遮挡程度以及目标运动模式均无约束。     

M2Tracker: A Multi-View Approach to Segmenting and Tracking People in a Cluttered Scene

When occlusion is minimal, a single camera is generally sufficient to detect and track objects. However, when the density of objects is high, the resulting occlusion and lack of visibility suggests the use of multiple cameras and collaboration between them so that an object is detected using information available from all the cameras in the scene.In this paper, we present a system that is capable of segmenting, detecting and tracking multiple people in a cluttered scene using multiple synchronized surveillance cameras located far from each other. The system is fully automatic, and takes decisions about object detection and tracking using evidence collected from many pairs of cameras. Innovations that help us tackle the problem include a region-based stereo algorithm capable of finding 3D points inside an object knowing only the projections of the object (as a whole) in two views, a segmentation algorithm using bayesian classification and the use of occlusion analysis to combine evidence from different camera pairs.The system has been tested using different densities of people in the scene. This helps us determine the number of cameras required for a particular density of people. Experiments have also been conducted to verify and quantify the efficacy of the occlusion analysis scheme.     

A hybrid tracking method for scaled and oriented objects in crowded scenes

Traditional kernel based means shift assumes constancy of the object scale and orientation during the course of tracking and uses a symmetric/asymmetric kernel, such as a circle or an ellipse for target representation. In a tracking scenario, it is not uncommon to observe objects with complex shapes whose scale and orientation constantly change due to the camera and object motions. In this paper, we propose a multi object tracking method which tracks the complete object regions, adapts to changing scale and orientation, and assigns consistent labels to each object throughout real world video sequences. Our approach has five major components: (1) dynamic background subtraction, (2) level sets, (3) mean shift convergence, (4) object identification, and (5) occlusion handling. The experimental results show that the proposed method is superior to the traditional mean shift tracking in the following aspects: (1) it provides consistent multi objects tracking instead of single object throughout the video, (2) it is not affected by the scale and orientation changes of the tracked objects, (3) its computational complexity is much less than traditional mean shift due to using level set method instead of probability density.