Time efficient ghost removal for motion detection in visual surveillance systems

Segmentation of foreground objects is an important and essential task for many systems that aim to carry out motion tracking, object classification, event detection and is used in applications such as traffic monitoring and analysis, access control to special areas, human and vehicle identification and the detection of anomalous behaviour. The most common approach for detecting moving objects is background subtraction, in which each frame of a video sequence is compared against a background model. A large number of background subtraction algorithms have been proposed [1], but problems remain for moving object identification under certain conditions. One of the toughest problems in background subtraction is caused by the detection of false objects when an object that belongs to the background (e.g. after staying stationary for some time) starts to move away. This generates what are called `ghosts?. It is important to address the problem because ghost objects will adversely affect many tasks such as object classification, tracking and event analysis (e.g. abandoned item detection). This Letter focuses on the problem of ghost identification and elimination. We used a state-of-the-art industrial tracker which includes basic background subtraction and object tracking. Then we included our ghost detection algorithm into the basic tracker to identify and eliminate ghosts. Finally, we systematically evaluated and compared performance on urban traffic video sequences.     

云杂波背景图像序列中小目标检测算法研究

云杂波背景图像序列中运动小目标的实时检测算法,是红外精确制导系统中的关键算法之一。首先对云杂波背景图像像素进行分类分析,研究了两种最大顺序滤波器和利用序列图像中像素时域剖面检测小目标的自适应方差滤波器算法,继而提出了一种适合云杂波背景的小目标检测算法。使用此算法对两组真实图像序列中运动小目标进行检测,根据对检测结果的分析,指出此算法可有效地完成检测任务,并且具有运算简单、存储量小、可并行实现、实时性好等特点。最后提出了后续工作的方向。     

基于二维频域投影的弱小运动目标检测方法

针对光学成像弱小运动目标难以准确快速检测问题,提出了基于图像序列行列最大投影的二维频域运动小目标检测算法。首先,为了减少计算复杂度和使目标背景分离,将经过背景全局运动补偿后的视频向二维频域投影并去除频率为零的成分,从而获得含弱小运动目标和噪声的图像序列;其次,通过行列序列最大投影,得到信噪比提高的含弱小运动目标的行列图像;然后,通过主运动滤波和图像重构,检测到滤除配准误差和噪声的弱小运动目标;最后,针对强噪声干扰下的弱小运动目标检测问题进行了仿真实验,仿真结果表明,所提算法不仅可有效的检测出弱小运动目标,而且相对单一的行列分解图像在二维频域内有更高的检测信噪比。     

Detecting moving object from dynamic background video sequences via simulating heat conduction

Moving object detection is one of the essential tasks for surveillance video analysis. The dynamic background often composed by waving trees, rippling water or fountains, etc. in nature scene greatly interferes with the detection of moving objects in the form of noise. In this paper, a method simulating heat conduction is proposed to extract moving objects from dynamic background video sequences. Based on the visual background extractor (ViBe) with an adaptable distance threshold, we design a temperature field relying on the generated mask image to distinguish between the moving objects and the noise caused by dynamic background. In temperature field, a brighter pixel is associated with more energy. It will transfer a certain amount of energy to its neighboring darker pixels. Through multiple steps of energy transfer the noise regions loss more energy so that they become darker than the detected moving objects. After heat conduction, K-Means algorithm with the customized initial clustering centers is utilized to separate the moving objects from background. We test our method on many videos with dynamic background from public datasets. The results show that the proposed method is feasible and effective for moving object detection from dynamic background sequences.     

动态规划算法在运动点目标检测中的应用研究

序列图像中低信噪比运动点目标的实时检测算法,是许多实时处理系统中的关键算法之一。该文在对面临的实际问题与对检测算法分析的基础上,详细阐述和研究了利用LS线性预测器的动态规划能量累积算法,并根据仿真实验的效果,指出此算法较直接动态规划能量累积算法可最大程度地降低能量扩散,减少团聚在目标周围的虚警目标点,十分利于后续轨迹关联检测处理.     

Moving object detection in wavelet compressed video

In many surveillance systems the video is stored in wavelet compressed form. In this paper, an algorithm for moving object and region detection in video which is compressed using a wavelet transform (WT) is developed. The algorithm estimates the WT of the background scene from the WTs of the past image frames of the video. The WT of the current image is compared with the WT of the background and the moving objects are determined from the difference. The algorithm does not perform inverse WT to obtain the actual pixels of the current image nor the estimated background. This leads to a computationally efficient method and a system compared to the existing motion estimation methods.     

基于图像融合的空间运动目标检测算法

文中提出了一种结合背景减除法和瞬时差分法在图像序列中检测运动目标的算法．算法利用瞬时差分法得到当前图像中运动目标的轮廓信息,在更新背景模型时不更新运动目标轮廓内区域,避免了由运动目标引起的背景模型更新误差．实验结果表明,该方法可以实现静止背景下图像序列中运动目标的检测,具有实时性,并能得到较好的检测结果．     

Robust shape-matching criterion for precision tracking of moving objects in correlated image sequences

A robust shape-matching measure with a boundary detection preprocessor is proposed to track a moving object in complex image sequences. A correlation-tracking algorithm seeks to align the incoming target image with the reference image of the target. But it has a critical problem if we use the conventional block-matching criteria. This is the so-called 'false peak problem', which is generally caused by highly correlated background pixels with similar intensities to the pixels of moving targets. The robustness of the proposed method for practical application is demonstrated by simulating two kinds of real-target image sequences.     

基于背景重构的运动对象越界侦测方法

提出了一种基于背景重构的运动对象越界侦测方法,该算法利用当前视频图像和背景视频图像,通过差分法获取运动对象模型和背景差值,再利用运动对象模型的连续性绘制运动对象轨迹,对轨迹和警戒线交叉方程进行越界侦测。同时,利用当前视频图像融合背景图像生成新的背景图像,能有效保证识别算法的自适应性,提高侦测结果的准确性。     

Object detection using spatio-temporal thresholding in image sequences

An algorithm using spatio-temporal thresholding for object detection with spatio-temporal distance metric in image sequences is proposed. The distance metric consists of the feature which uses the intensity and gradient at the same time in feature level instead of in decision level. In the model update process truncated variable adaptation rate is used, which can control adaptation rate up to its statistics, so it is able to maintain its statistics properly through the whole sequence. Some experimental results in various environments show that the averaged performance of the proposed algorithm is good.     

基于背景差分和混合帧差的运动目标检测

针对利用核密度估计建立背景模型时计算量大,运动目标和外界环境容易发生变化,提出一种基于改进的核密度估计背景差分法和改进的混合帧差法相结合的运动目标检测方法。该方法在背景建模时,先对背景差分后的图像进行分块和分类,并简化了核密度估计的核函数,对前景块中的像素进行核密度估计,减少了计算量。在混合帧差法中增加了动态阈值,提高了对光线变化的适应性。实验结果表明该方法能够完整地提取出运动目标,提高了目标检测的准确率。     

基于显著性检测的星载嵌入式跟踪系统

随着航天科技的不断发展,计算机视觉算法在卫星上的应用方兴未艾,为了实现更多的功能需求和应对可能的威胁,视觉目标跟踪作为其中基础但具有挑战性的任务更是至关重要。然而,目前已有的目标跟踪算法大多数算法只限于对图像序列进行跟踪。另一方面,受到硬件条件制约,很多优秀的算法因为复杂度较高很少被应用到星载嵌入式系统中。这些目标跟踪算法运行时,通常需要人为地给出目标的边界框。为了自动得到边界框,需要目标检测算法对输入图像进行运动目标检测。本文提出了一种基于显著性检测和相关滤波的单目标检测与跟踪一体化算法,并与嵌入式系统相结合,在搭载的TMS320C6678芯片上达到了2 048 pixel×2 048 pixel分辨率下24 fps的帧率。具体地,检测算法负责对图像进行预处理并获得边界框,然后目标跟踪算法给出目标在后续帧中的位置。为了验证算法在实际跟踪中的有效性,本研究搭建了一个由相机、DSP和云台组成的光学平台并进行了实验验证。在该系统中,DSP自动完成检测、跟踪、驱动云台和再检测任务,达到了很好的检测跟踪效果。     

Automatic Segmentation of Moving Objects in Video Sequences for Indoor and Outdoor Applications

1　IntroductionAutomaticsegmentationofmovingobjectsfromvideosequencesisadifficultandchallengingproblemincomputervisionsystems.Ithasmanyapplicationssuchasvideosurveillance,trafficmonitoring ,peopletrackingandvideocommunication[1～4] .Italsoplaysanimportantroleinsupportingcontent basedimagecoding,especiallyaftertheemergenceofthevideocodingstandardMPEG 4[5～ 1 4 ] .Therearealotofresearchworksonmovingob jectssegmentationandextraction .Thesealgorithmscanberoughlyclassifiedintotwocategories:inter …     

Human object interaction detection based on feature optimization and key human-object enhancement

Aiming at the problem of unclear or missing human object interaction behavior objects in complex background, we propose a human object interaction detection algorithm based on feature optimization and key human-object enhancement. In order to solve the problem of missing human behavior objects, we propose Feature Optimized Faster Region Convolutional Neural Network (FOFR-CNN). FOFR-CNN is an object detection network optimized by multi-scale feature optimization algorithm, taking into account both image semantics and image structure. In order to reduce the interference of complex background, we propose a Key Human-Object Enhancement Network. The network uses an instance-based method to enhance the features of interactive objects. In order to enrich the interaction information, we use the graph convolutional network. Experimental results on HICO-DET, V-COCO and HOI-A datasets show that the proposed algorithm has significantly improved accuracy and multi-scale object detection ability compared with other human object interaction algorithms.     

一种基于能量差比较算法的差分运动检测方法的改进

本文利用人眼对边缘(空间梯度)特别敏感的视觉特点,把帧间运动变化检测和图像的边缘检测结合起来,对帧间差分法进行了改进。首先,本文构造了一个二维运动探测器,将各向异性自适应边缘检测算子扩展到动态图像处理中,提出了,运动像素的能量差比较算法。该算法能够对运动目标各个运动像素的运动方向起到一个优化加强的作用,最终得到各个方向上的最佳检测。实验证明,这种算法可以很好的强化每个像素的运动方向,达到最佳的检测效果。     

基于OpenCV的运动目标跟踪系统研究

本文分析比较了传统运动目标检测的3种主要方法：背景图像差分法、时态差分法和光流法,在此基础上给出了一种背景图像预测算法,大大减少了因为背景变化而产生的目标检测误差。本文基于OpenCV设计出改进的运动目标检测与跟踪算法,实现了运动目标的跟踪,并在VC＋＋编译环境下,利用USB摄像头作为视频采集器,通过观察实验结果可以看出,本文的运动目标检测算法能够正确地检测出视频图像中的运动目标,而且在检测性能上优于普通的自适应背景差分法。     

基于图像序列的运动目标检测研究

提出一种基于图像序列的运动目标检测算法。采用相位相关算法计算由于摄像机运动而导致的图像背景的平移量和旋转量,引入自适应阈值对待处理图像做平滑处理,进行图像配准处理,最后在差分相乘算法之前采用高通滤波处理,滤除噪声,增强边界以提取运动目标。实验结果表明该方法在工程实践中具有良好的性能和很强的适应能力。     

基于自适应背景图像更新的运动目标检测方法

在运动目标的实时检测中常用的方法是背景图像差分法,但因其缺乏背景图像随监视场景光照变化而及时更新的合理方法,限制了本方法的适应性.对此,本文首先提出了一种基于光流场等技术的自适应背景逼近更新方法,并根据彩色差值模型得到差分图像;然后引入Gauss模型实现运动目标的自适应阈值分割.实验结果表明:本文提出的背景更新方法可随着光照条件的变化实时、准确地更新背景图像,在此基础上提出的基于Gauss模型的自适应阈值分割方法可以实现运动目标的完整分割,这为运动目标的后续识别与理解奠定了基础.     

Building Recognition Based on Geometric Model in FLIR Image Sequences

In this paper, we propose a novel method for building recognition from forward looking infrared (FLIR) image sequences with clutter in the background for automatic target recognition (ATR). In the first phase, dynamic feature space is defined, and camera model and multi-scale characteristic views model that are used to predict model’s features based on 3D object reference model are introduced. In the second phase, the original image is preprocessed using morphological grayscale filters that respond to the size, shape and orientation of object to suppress the background that contains the non-stationary nature and man-made objects of the clutter image. In the following phase, segmentation for the result of image preprocessing is used to obtain regions of interest (ROIs), and features extraction of ROIs and matching retain ROIs that are closest to predicted features. Lastly, the object is identified by fusing the line features. Experiment results show the algorithm can recognize the object from FLIR image sequences with a complicated background.     

室内夜间微弱光源下运动目标检测和阴影去除

提出一种新的室内夜间微弱光源照明情况下的运动目标检测方法。首先进行背景建模, 获取稳固的背景图像, 之后对背景和当前帧图像进行图像增强处理, 提高其清晰度; 采用相对背景减法检测前景运动目标, 并对差分图像进行去噪和修补; 利用前景目标区域、阴影区域和背景区域像素亮度值存在差异的特点, 检测和去除背景差分图像中可能存在的阴影, 获得准确的运动目标。在室内夜间环境下采集视频进行试验, 结果验证了所提方法的有效性。