一种改进型的粒子滤波器

针对复杂背景条件下图像序列中跟踪运动目标的问题,提出一种改进的粒子滤波图像跟踪算法,该算法利用遗传算法的研究成果,采用选择、交叉、变异等步骤实现对粒子的重采样,解决了粒子滤波器所面临的粒子退化和匮乏问题.由于该算法利用了遗传算法的全局寻优特性,因此该算法具有较强的稳健性.同时,粒子滤波可实现非线性非高斯状态空间模型的最优估计,将该粒子滤波用于目标跟踪,具有较好的过遮挡能力.实验结果表明,该算法状态估计性能好,能够很好地实现复杂图像序列中的目标跟踪.     

基于改进的混合高斯模型的运动目标检测方法

为了改善混合高斯模型在光照突变时容易产生大量误检的缺陷,采用了一种高斯模型与均值法相结合并为前景像素建立计数器的方法。在建立背景模型时,运用多帧图像求平均值的方法初始化混合高斯模型的背景;为每帧图像的前景像素数建立计数器,并以此消除被误判为前景的区域;对检测出的前景区运用数学形态学处理,得到图像真正的前景区域。结果表明,该算法不仅克服了初始背景中的干扰,而且消除了光照突变时的误检,提高了运动目标的检测率。     

基于改进的混合高斯模型的红外运动目标检测

传统混合高斯模型中背景容易留下运动"虚影",同时在噪声或目标区域对比度低时会导致提取目标区域时出现断裂和空洞的现象,针对这些问题在混合高斯方法中赋予图像中运动和静止区域不同的背景更新速率,并充分利用混合高斯模型中的背景和前景信息,将背景减除的结果与高斯建模中的前景图像按照一定比例融合获得目标图像。实验结果表明:改进后的混合高斯模型运动目标检测方法,能够克服传统高斯模型目标检测中存在的问题,从复杂的背景中较完整的提取出运动目标,且具有一定的抗噪能力。     

基于目标跟踪和多特征融合的火焰检测算法

针对目前视频火焰检测算法无法达到高检测率、低误检率和实时的工业需求,提出一种基于目标跟踪和多特征融合的火焰检测算法.首先利用混合高斯背景建模获取前景图像,在HSV色彩空间中根据火焰的颜色特性分离出疑似火焰区域,对火焰疑似区域采用卡尔曼滤波器实现运动目标的跟踪,再结合火焰的相似度、区域增长率和跳动频率特征用加权求和得到的值与报警阈值相比,最后根据判断比较确定真实火焰区域,并且实现对火焰的持续跟踪.实验结果证明,该算法能够对火焰区域进行有效的检测与跟踪并且具有良好的实时性和抗干扰能力.     

基于YC_bC_r颜色空间的背景建模及运动目标检测

高斯混合模型广泛应用于基于背景建模的运动目标检测中。首先在YCbCr颜色空间采用自适应高斯混合模型对背景的每个像素建模;然后,对输入的当前帧图像的每一像素值与该像素点对应的高斯混合背景模型的各个高斯模型进行比较,将前景运动区域（包括运动目标、投射阴影）从场景中提取出来;最后,采用局部二元图（Lo-cal Binary Pattern,LBP）来提取纹理特征,利用背景在阴影覆盖前后的纹理相似性去除投射阴影,同时结合阴影的空间几何特性优化运动目标检测结果。实验结果表明,该算法能有效地检测出投射阴影和运动目标,具有较高的实际应用价值。     

自适应复杂背景干扰的运动目标检测算法

基于视频图像的运动目标检测,是根据目标的像素特征来判别出相对于背景运动的目标,当图像背景动态变化时,将难以区分背景和运动目标的像素特征,易造成检测错误。复杂背景下的运动目标检测是一大难点,目前主流的运动目标检测算法在背景灰暗、水面波动、气流颤动等复杂背景干扰下,难以准确地检测出运动目标。针对上述问题,提出一种自适应复杂背景干扰的运动目标检测算法,采用新的前景判断和背景模型更新方法,同时设计了一种创新型自适应阈值更新方法,当视频背景变化时,自动更新阈值。该算法增强了对复杂背景、镜头抖动的抗干扰能力,通过各种视频测试,背景点检测正确率达到0.9958,前景点检测正确率达到0.8012,极大提高了前景检测率,而且该算法满足高实时性要求,对复杂背景下的运动目标检测有显著效果。     

改进高斯混合模型的运动目标检测算法

传统的高斯模型无法检测比较复杂的场景或速度较低的运动目标,因此提出基于改进高斯混合模型的运动目标检测算法。使用多个高斯模型表示运动目标图像内各像素点特征,并基于图像内各像素点与高斯混合模型相匹配则视其为背景点,反之为前景点原理,更新高斯混合模型。通过更新前景模型并计算短时稳定度指标,提高运动目标检测效果,通过确定高斯分布与像素关系,设定新的参数构造背景模型,消除光照突变造成的影响。实验分析结果表明,该方法能够很好地检测与跟踪运动目标,且抗噪性能好、清晰度高,准确率高达98%。     

基于Android平台的视频运动目标检测系统

为了在Android平台上实现实时性好,抗噪声性能强的视频序列运动目标检测系统。本文提出了一种融合单高斯背景模型和帧间差分的运动目标检测算法。该算法提取出帧间差分法检测的运动目标区域,并对该区域采用基于单高斯模型的背景差分算法提取出运动目标,然后对高斯背景图像进行更新。实验结果证明,该算法能够有效降低背景扰动的影响,增强检测出的运动目标的完整性,而其复杂度仅为两种组成算法之和的73.9%,在Android平台上运行效果良好。     

背景抑制直方图模型的连续自适应均值漂移跟踪算法

针对传统连续自适应均值漂移(CAMshift)跟踪算法在建立目标颜色模型阶段容易包含大量背景颜色信息从而使跟踪效果变差的问题,该文提出一种改进算法。利用混合高斯模型背景法(GMM)将原始图像分割成前景和背景的叠加,在原始图像和背景图像上运动物体所在区域分别建立色调分量直方图,利用背景图像的色调分量直方图计算原始图像中对应色调分量的权值,抑制原始图像中与背景颜色相同的色调,扩大前景与背景颜色的差异性。该方法通过对原始颜色模型中属于背景的色调进行抑制,扩大了目标颜色模型的显著性,提高了跟踪的准确性和稳定性,目标定位的最大中心误差小于20%,能够准确跟踪不发生丢失。     

交通视频的移动目标检测算法研究

对视频序列的目标进行识别和跟踪监控是计算机视觉领域的关键技术。依据图像处理和目标检测研究方向的热点算法,将帧间差分与混合高斯背景模型融合法应用于交通视频移动车辆的目标检测分析中。该算法通过背景差分求出光照影响的动态阈值范围,若光照检测阈值小于该动态阈值,选择混合高斯背景模型法,大于该动态阈值则选取帧间差分法。再通过开运算、闭运算、连通域计算,以及区域的凸包形态学运算即可准确描述目标。实验结果表明,该融合算法消除了鬼影现象,在光照环境改善的情况下可以有效应用于交通视频中移动车辆的目标检测。     

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。     

Independent Component Analysis-Based Background Subtraction for Indoor Surveillance

In video surveillance, detection of moving objects from an image sequence is very important for target tracking, activity recognition, and behavior understanding. Background subtraction is a very popular approach for foreground segmentation in a still scene image. In order to compensate for illumination changes, a background model updating process is generally adopted, and leads to extra computation time. In this paper, we propose a fast background subtraction scheme using independent component analysis (ICA) and, particularly, aims at indoor surveillance for possible applications in home-care and health-care monitoring, where moving and motionless persons must be reliably detected. The proposed method is as computationally fast as the simple image difference method, and yet is highly tolerable to changes in room lighting. The proposed background subtraction scheme involves two stages, one for training and the other for detection. In the training stage, an ICA model that directly measures the statistical independency based on the estimations of joint and marginal probability density functions from relative frequency distributions is first proposed. The proposed ICA model can well separate two highly-correlated images. In the detection stage, the trained de-mixing vector is used to separate the foreground in a scene image with respect to the reference background image. Two sets of indoor examples that involve switching on/off room lights and opening/closing a door are demonstrated in the experiments. The performance of the proposed ICA model for background subtraction is also compared with that of the well-known FastICA algorithm.      

用于监控视频的滞留与搬移物体的检测算法

提出了一种新的滞留与搬移物体的检测分类算法.该算法利用背景差法获得前景图像,然后进行二值化和形态学处理,再和背景帧进行比较来对滞留和搬移物体进行检测和分类.实验结果表明该检测算法具有较高的正确率和鲁棒性.     

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.     

Reliable moving vehicle detection based on the filtering of swinging tree leaves and raindrops

An efficient method for detecting moving vehicles based on the filtering of swinging trees and raindrops is proposed. To extract moving objects from the background, an adaptive background subtraction scheme with a shadow elimination model is used. Swinging trees are removed from foreground objects to reduce the computational complexity of subsequent tracking. Raindrops are removed from foreground objects when necessary. Performance evaluations are carried out using seven real-world traffic image sequences. Experimental results show average recognition rates of 96.83% and 97.20% for swinging trees and raindrops, respectively, indicating the feasibility of the proposed method.     

运动人体轮廓检测算法的分析与改进

在视频序列的人体运动分析中,实时分割出运动的人体,是研究的关键步骤。为了克服不均匀光照、前景运动缓慢、背景中存在摇摆的树叶等因素对检测带来的影响,提出了一种背景减除法与帧间差分相结合的运动目标检测方法。该方法首先通过基于帧差法的背景模型建立方法建立背景图像,再结合背景减除与带有权值的帧间差分检测运动目标,降低目标物体对速度和环境干扰的敏感性。最后通过形态学梯度运算操作消除外界噪声的影响。实验结果表明,本文提出的算法计算简单,对环境适应能力较强,是一种有效的运动人体检测方法。     

一种有效的图像阴影自动去除算法

目标跟踪与检测研究中,在检测运动前景时也会检测到运动目标投射的阴影。阴影使得运动目标发生几何变形,可能造成运动目标粘连,甚至造成检测不到目标。阴影去除后才能较真实的得到运动目标重心。本文研究一种利用图像YCbCr颜色信息去除阴影的方法。首先利用背景减的方法得到带影子的目标区域,其次进行YCbCr空间的背景减,由于影子和目标物体在YCbCr空间背景减信息有较大差别,因此可以通过阈值判断得到去影之后的精确目标区域,目标物体识别的精确性和鲁棒性将会得到提高。实验结果表明,该方法在去除阴影的同时又较好地保留了前景目标的信息,是一种有效的阴影去除方法。      

复杂背景下基于贝叶斯-全概率联合估计的前景检测

针对复杂背景下前景提取较为困难或者提取准确率较低等问题,该文提出了基于贝叶斯-全概率联合估计的目标检测模型并引入了背景误差控制变量的概念。通过选择适当的特征向量,在贝叶斯-全概率估计模型下,背景像素将会分为静止与运动两种不同的类型,进而准确提取前景像素点。实验结果表明,该模型是一个较为通用的目标检测模型,在目标提取时,该文算法对各种类型的视频背景环境(包括复杂背景)都具有较好的适用效果。     

Vehicle Tracking and Speed Measurement system (VTSM) based on novel feature descriptor: Diagonal Hexadecimal Pattern (DHP)

Object detection and tracking is an important and active research area in computer vision community. The proposed Vehicle Tracking and Speed Measurement (VTSM) system can find out speed parameters of the vehicles. Speed parameters are used to take judgment on accidents at a low cost. The main objective of this paper is to develop an algorithm that can detect foreground, track specified object and calculate speed parameter of the object. Identifying stationary background from moving objects in a video is a critical task. To achieve superior foreground detection quality across unconstrained scenarios, a novel dynamic background subtraction and object tracking algorithm using a novel Diagonal Hexadecimal Pattern (DHP) is proposed. Metric F-score and MOTA are used to measure the performance of the proposed system. From the results, it is observed that the proposed system gives good results for the background subtraction and tracking.     

复杂背景下的运动目标分割与阴影消除

针对目前运动对象分割不完整,以及存在阴影和鬼影对运动目标分割的影响,提出了一种基于复杂背景下的运动目标分割与阴影消除方法.首先利用高斯混合模型进行初始背景建模并提取初始前景对象,将当前视频帧和背景模型进行差分运算,且通过多尺度小波变换时空域特征,将多尺度分析和图像分割相结合,压制阴影并消除鬼影对运动目标分割的影响而得到...