采用UKF建模的实时背景提取和运动阴影检测

实时运动物体分割是实现智能视频监控和视频交通流量检测等视觉系统的基础。目前,影响运动检测的因素主要有两个方面,一是背景建模的准确性;二是运动阴影的干扰。提出了基于无偏卡尔曼滤波器(UKF)的背景提取和阴影检测方法,构建整体的运动物体检测框架。该方法通过对背景和阴影建模,分别从帧间差分和背景差分两个层次综合分析像素值的动态变化特性,并利用色彩和亮度变化特性检测出运动阴影,最后借助UKF对两个模型参数进行在线更新,实现实时的运动物体分割。与现有算法相比,该方法背景跟踪速度快、运动检测效果好、计算量较小。实验结果证明了该方法的有效性和实用性。     

基于混合高斯模型的运动目标检测

提出了一种新的基于HSV颜色空间的阴影检测和误判检测的自适应背景模型运动目标检测算法,并将其应用于运动物体的分割。该算法较好地解决了背景模型的提取、更新、背景扰动、外界光照变化等问题。实验结果表明了该算法的实时性、可靠性和准确性较好。     

基于阴影检测的HSV空间自适应背景模型的车辆追踪检测

在交通监控中，要进行车辆的检测、车流量统计、实时追踪、车速测定等工作，而如何从复杂的背景中分割运动物体是至关重要的一步，目前采用的典型方法是背景相减方法。为了对运动车辆进行准确快速的检测，在研究了目前存在的各种方法之后，提出了一种新的基于阴影检测的HSV空间自适应背景模型的车辆追踪检测算法，并将其应用于运动物体的分割，同时给出了具体的试验结果。该方法之所以不在传统的RGB空间实现，而在HSV空间实现，因为HSV空间可以提供更丰富的颜色信息。运行试验结果表明，该方法准确率高，适应性强，运算速度快，兼具灵活性，能满足实时检测的需要。     

基于视频图像的高速公路车辆检测算法研究

针对高速公路智能交通系统中的复杂场景变化、阴影和车辆遮挡等影响车辆检测率的问题,提出了使用基于高斯混合模型的自适应方法来建立和更新背景,采用基于HSV的邻域均值快速阴影消除算法提高阴影消除的速度。对于遮挡车辆,采用基于Kalman滤波的识别算法进行遮挡车辆的识别,然后使用基于模板匹配的金字塔分级搜索算法对遮挡车辆进行细分割。实验结果表明,该算法既简单又有效,车辆的检测率达到97%,完全满足车辆检测的要求。     

基于主动轮廓模型的交通场景运动目标提取算法

在交通监控中,从复杂的交通场景中精确地分割出运动目标是至关重要的。目前,经典的运动目标检测算法有背景差法和帧差法。当场景中存在阴影时,这两种方法都不能够精确地提取运动目标。提出了一种基于主动轮廓模型的运动目标提取算法。通过阴影检测,从运动目标中获得消除阴影的初始轮廓,然后通过主动轮廓模型逼近运动目标真实轮廓。实验表明,该算法既可以消除阴影和噪声的影响,又可以保持运动目标完整。     

煤矿智能视频监控中的运动目标检测研究

针对煤矿智能视频监控环境存在各种复杂动态场景变化的情况,研究了运动目标检测中的3个重要环节:背景建模与更新、前景检测和运动阴影检测与去除。针对这3个环节,提出了相应的处理方法:基于IFCM聚类算法的自适应背景建模与更新方法,对像素灰度取值进行无监督聚类,自适应选取不同个数的聚类构建各像素背景模型,随场景变化进行聚类修改、添加和删除以完成背景自动更新;联合背景差分信息、三帧差分信息和空间邻域信息的前景检测方法,据此获得较为准确的前景目标;运动阴影检测与去除方法,依据在阴影覆盖前后的灰度图像中,像素具有亮度值相关性和纹理特征值不变性,实现了运动阴影的检测与去除。实验结果验证了本文所提方法的有效性和优越性。     

视频监控系统中运动目标检测的阴影去除方法

在分析了阴影产生的原因及视觉特性的基础上,针对固定场景的运动目标检测问题,提出了一种具有实际应用价值的阴影检测与去除方法。该方法通过背景建模和背景差分方法分割出运动目标及其可能存在的阴影,采用光照评估方法判断阴影是否存在,进而运用多梯度分析和二值图像的快速聚类算法检测出阴影,去除阴影并分割运动目标。实验验证了该方法的有效性。     

一种基于全向视觉的运动物体检测算法

针对静态摄像头条件下的运动物体,提出一种基于全向图像特性的运动目标检测算法.首先对全向图像进行展开,并应用非线性畸变模型对展开图像校正处理,利用自适应背景建模的方法建立和更新背景模型、去除背景,实现对运动物体的识别与检测.该方法利用全向校正图像分辨率低的特点较好地解决前景提取过程中的噪声和阴影问题.实验表明,该方法对于全向视觉条件下运动物体的检测是快速有效的.     

利用改进的背景模型实现车辆检测

为解决基于背景差分的车辆检测办法易受交通状况影响的问题,首先建立基于区间分布的自适应背景模型,然后利用改进的背景更新算法对建立的背景模型选择性更新,最后结合阈值分割和形态学处理实现运动车辆检测.实验结果表明,该算法在交通堵塞或临时停车等复杂交通环境中有很好的背景提取和更新效果.与经典的算法相比,该车辆检测算法在实时性和准确性方面都有所提高.     

车辆视频检测及阴影去除

针对智能交通系统的车辆检测问题,提出了一种运动车辆检测及阴影去除的方法。采用基于背景差与帧间差的方法来检测运动视频中的车辆,对背景差和帧间差检测出的车辆进行或运算得到运动目标。再对检测出的运动目标进行形态学处理,并结合色彩及阴影统计信息建立阴影模型,去除阴影。实验结果表明,该方法能够快速、准确地在动态视频中分割出运动车辆和阴影。     

Moving vehicles detection based on adaptive motion histogram

As one of the important topics in computer vision, moving vehicle segmentation has attracted considerable attention of researchers. However, robust detection is hampered by the interferential moving objects in dynamic scenes. In this paper, we address the problem of the moving vehicles segmentation in the dynamic scenes. Based on the distinct motion property of the dynamic background and that of the moving vehicles, we present an adaptive motion histogram for moving vehicles segmentation. The presented algorithm consists of two procedures: adaptive background update and motion histogram-based vehicles segmentation. In the adaptive background update procedure, we make use of the lighting change of the scene and present a novel method for background evolving. In the motion histogram-based vehicles segmentation procedure, an adaptive motion histogram is maintained and updated according to the motion information in the scenes, and the moving vehicles are then detected according to the motion histogram maintained. Experimental results of typical scenes demonstrate robustness of the proposed method. Quantitative evaluation and comparison with the existing methods show that the proposed method provides much improved results.     

圆锥裁剪BLOB的视频目标检测方法

真实场景的视频目标检测需要消除阴影、反射和鬼影等噪声的影响,以检测出运动目标和静止目标.为了实现系统性的视频目标检测,提出一种自适应圆锥裁剪联通块(TC-BLOB)榆测方法.基于BLOB知识,将3D颜色空间变换为"夹角-模差"2D空间后,定义一套圆锥裁剪规则划分出阴影BLOB和反射BLOB;再以一种持久化记忆PM方法判别出鬼影BLOB;最后改进双背景模型检测出静止目标和运动目标.采用不同环境视频进行实验的结果表明,文中方法足有效的,并有独立于后续跟踪的优点.     

Background subtraction using finite mixtures of asymmetric Gaussian distributions and shadow detection

Foreground segmentation of moving regions in image sequences is a fundamental step in many vision systems including automated video surveillance, human-machine interface, and optical motion capture. Many models have been introduced to deal with the problems of modeling the background and detecting the moving objects in the scene. One of the successful solutions to these problems is the use of the well-known adaptive Gaussian mixture model. However, this method suffers from some drawbacks. Modeling the background using the Gaussian mixture implies the assumption that the background and foreground distributions are Gaussians which is not always the case for most environments. In addition, it is unable to distinguish between moving shadows and moving objects. In this paper, we try to overcome these problem using a mixture of asymmetric Gaussians to enhance the robustness and flexibility of mixture modeling, and a shadow detection scheme to remove unwanted shadows from the scene. Furthermore, we apply this method to real image sequences of both indoor and outdoor scenes. The results of comparing our method to different state of the art background subtraction methods show the efficiency of our model for real-time segmentation.     

Incremental Tensor Subspace Learning and Its Applications to Foreground Segmentation and Tracking

Appearance modeling is very important for background modeling and object tracking. Subspace learning-based algorithms have been used to model the appearances of objects or scenes. Current vector subspace-based algorithms cannot effectively represent spatial correlations between pixel values. Current tensor subspace-based algorithms construct an offline representation of image ensembles, and current online tensor subspace learning algorithms cannot be applied to background modeling and object tracking. In this paper, we propose an online tensor subspace learning algorithm which models appearance changes by incrementally learning a tensor subspace representation through adaptively updating the sample mean and an eigenbasis for each unfolding matrix of the tensor. The proposed incremental tensor subspace learning algorithm is applied to foreground segmentation and object tracking for grayscale and color image sequences. The new background models capture the intrinsic spatiotemporal characteristics of scenes. The new tracking algorithm captures the appearance characteristics of an object during tracking and uses a particle filter to estimate the optimal object state. Experimental evaluations against state-of-the-art algorithms demonstrate the promise and effectiveness of the proposed incremental tensor subspace learning algorithm, and its applications to foreground segmentation and object tracking.     

动态阈值的Vibe运动目标检测

Vibe算法是一种高效的像素级背景建模算法,但是它同混合高斯模型一样,不能适应光线突变的问题,在对Vibe算法的基础上提出了一种在静态场景下对光照变化鲁棒的运动目标检测方法。该方法首先利用Vibe模型建立背景样本集,并利用Vibe模型对判别为背景的像素对背景帧进行更新。其次视频当前图像帧与背景帧差分,并采用Otsu算法计算图像的分割阈值来检测运动目标。实验结果表明,改进的方法能够很好地消除由于环境光照变化引起的“曝光”现象,提高了运动目标检测的精确度,并且改进的算法对室内场景下的阴影也有较好的抑制作用。     

交通场景中的实时多目标跟踪方法

针对多目标检测与跟踪技术的应用要求,提出一种用于交通场景的实时多目标跟踪方法。设计背景建模算法和基于角点动态特征的分层跟踪算法,利用背景建模算法提取视频帧前景,并在前景区域运用分层跟踪算法,包括Corner、Cluster和Object 3层架构,通过在不同层之间引入对应的聚类算法,以实现目标跟踪。实验结果表明,该方法适用于多数交通场景,对光照、阴影具有较强的鲁棒性。     

基于改进混合高斯模型和图形句柄的异常车辆检测

由于交通安全隐患在当下的生活中造成的不良影响越发严重,所以在步行街、校园等禁止车辆行驶的场景中,对异常车辆的检测具有一定的现实意义。针对利用混合高斯建立背景模型时易出现重影和空洞问题,提出了一种基于SSIM结构相似性的混合高斯建模的异常车辆检测,采用SSIM计算2幅图像像素点间的相似度,在高斯建模后进行二次背景建模,同时引入了指数函数来优化高斯建模过程中的权值更新过程,提高了更新速度。采用图形句柄函数优化连通域方法对前景区域进行异常车辆检测,能够检测出异常车辆且标注框更加贴近车辆形状。对580幅由视频分割得到的图像的实验结果表明,检测率可以达到90.3%。     

On line background modeling for moving object segmentation in dynamic scenes

Fast and accurate moving object segmentation in dynamic scenes is the first step in many computer vision applications. In this paper, we propose a new background modeling method for moving object segmentation based on dynamic matrix and spatio-temporal analyses of scenes. Our method copes with some challenges related to this field. A new algorithm is proposed to detect and remove cast shadow. A comparative study by quantitative evaluations shows that the proposed approach can detect foreground robustly and accurately from videos recorded by a static camera and which include several constraints. A Highway Control and Management System called RoadGuard is proposed to show the robustness of our method. In fact, our system has the ability to control highway by detecting strange events that can happen like vehicles suddenly stopped in roads, parked vehicles in emergency zones or even illegal conduct such as going out from the road. Moreover, RoadGuard is capable of managing highways by saving information about the date and time of overloaded roads.     

Road detection algorithm for Autonomous Navigation Systems based on dark channel prior and vanishing point in complex road scenes

Vision-based road extraction is essentially important in many fields, such as for intelligent traffic and robot navigation. However, the road detection in urban or ill-structured roads is still very challenging at current stage, and the existing methods often suffer from high computational complexity. This paper reports a novel and efficient method for road detection in challenging scenes. First, the dark channel based image segmentation is proposed to distinguish a rough road region from complex background noise, which is envisioned to reduce the workload of road detection. Furthermore, instead of using the conventional pixel-wise soft voting, a new voting strategy based on the vanishing point and the properties of the segmented regions is proposed to further reduce the computation time of road extraction stage. Finally, the segmented region which has the maximum voting value is selected as the road region. Experimental results demonstrated that the proposed algorithm shows superior performance in different kinds of road scenes. It can remove the interference from pedestrians, vehicles and other obstacles. Our method is about 40 times faster in detection speed, when compared to a recently well-known approach.     

一种基于改进码本的车辆检测与跟踪方法

为了解决固定摄像机下车辆跟踪过程中阴影对检测的影响,提出一种改进型码本模型的车辆检测方法。该方法直接对YUV空间的车辆序列进行处理,将采样到的背景值聚类成码本,对于新输入的像素值与其对应位置的码本作比较判断,提取出前景区域。车辆跟踪中采用Kalman预测的方法来处理车辆遮挡问题。实验结果表明,本算法可以从复杂交通场景图像序列中快速有效地检测出运动目标,能较好地处理阴影、高亮、遮挡和背景变化等问题,且计算复杂度小,能满足实时跟踪的需要。