适用于实时交通监控的时空可伸缩视频编码方法

提出了一种适用于视频监控的时空可伸缩编码方法。首先提出一种适用于可伸缩视频编码特点的监控算法,利用该算法将运动区域从背景中提取出来,并用模式和方向快速判别算法去掉对编码增益很小的冗余模式,基本层利用该算法进行编码,增强层利用基本层的信息预测可能的模式集合,然后进行零块预先判决,最后对最高时间级的高速运动块通过视觉门限来降低其空间冗余度。实验证明,该方法能够较大地提高编码速度和一定程度上提高压缩率,并且视觉质量损失很小。     

A fast method for moving object detection in video surveillance image

Moving object detection and extraction are widely used in video surveillance and image processing. In this paper, we present a fast method for moving object detection. We use weights of the Gaussian distribution as decision factors, update parameters of the Gaussian mixture model if its values are smaller than that of those not belonging to the background; otherwise, no updates are done. It improves the existing methods by updating the Gaussian mixture model selectively. Experimental results on various scenes of video surveillance show that computation time of the proposed method is reduced.     

Fast motion detection in compressed domain for video surveillance

A fast algorithm to detect motion in the compressed domain for video surveillance is presented. The algorithm partially decompresses the video bit stream and performs motion detection from its quantised discrete cosine transform coefficients. The very low computational cost makes this algorithm very useful when real-time motion detection has to be performed simultaneously in several video bit streams     

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。     

一种复杂场景下的视频流人脸隐私保护技术

查看视频监控的过程中,一些场景存在因为人脸面部信息暴露在监控视频中导致个人隐私信息泄露的风险,有必要对实时视频流中的行人隐私信息进行马赛克处理。目前市面上常见的基于人脸检测的打码方法在实时监控视频流上打码效果受行人姿态、光线影响较大,存在实时性差、漏检较多等问题。针对以上问题,提出了融合人脸检测算法、目标物体检测算法和前置帧关联检测方法的多检测模型,并与传统的人脸检测模型进行对比。实验结果表明,在人脸检测召回率上,所提模型相较于传统人脸检测算法提高了532%。     

PCA-based approach for video scene change detection on compressed video

An automatic, real-time detection approach to video scene change detection is presented. Owing to the high correlation of two consecutive video frames, it is proposed that only the eigenvector corresponding to the largest eigenvalue is retained in the principal component analysis (PCA) for video data. A one-dimensional PCA feature of video data is then generated from the PCA. It shows superior performance compared to the histogram feature and the pixel feature. The detection algorithm based on this PCA feature is then designed to detect both abrupt and gradual transitions. The proposed approach is tested on the TREC video test repository to validate its performance     

视频与AIS信息融合的海上目标检测

提出了一种视频与AIS信息融合的海上船只目标检测方法。首先结合AIS信息确定船只所在区域,提取小范围图像,然后对图像进行高频加强滤波处理,增强船只目标与海面背景的对比度,利用显著性区域检测方法生成显著性图像,随之采用双阈值分割提取高显著性目标,最后通过形态学处理判断船只目标。实验结果表明,该方法适应性强,能够准确快速地实现船只目标提取。     

CNN spatiotemporal features and fusion for surveillance video forgery detection

Surveillance cameras are widely used to provide protection and security; also their videos are used as strong evidences in the courts. Through the availability of video editing tools, it has become easy to distort these evidences. Sometimes, to hide the traces of forgery, some post-processing operations are performed after editing. Hence, the authenticity and integrity of surveillance videos have become urgent to scientifically validate. In this paper, we propose inter-frame forgeries (frame deletion, frame insertion, and frame duplication) detection system using 2D convolution neural network (2D-CNN) of spatiotemporal information and fusion for deep automatically feature extraction; Gaussian RBF multi-class support vector machine (RBF-MSVM) is used for classification process. The experimental results show that the efficiency of the proposed system for detecting all inter-frame forgeries, even when the forged videos have undergone additional post-processing operations such as Gaussian noise, Gaussian blurring, brightness modifications and compression.     

基于监控视频的行人异常行为检测技术研究

行人异常行为分析是视频监控领域中重要的研究方向.从基于规则、基于模型两方面对行人异常行为检测算法进行归纳总结,根据判定方式将算法分为阈值判定和分类判定,比较了各类算法的优势和不足,同时对使用较多的数据库进行了总结,最后讨论了异常行为研究在实际应用和未来研究中应该考虑的问题.     

面向多区域视频监控的运动目标检测系统

为了实现视频监控现场多区域运动目标检测,分析了传统运动检测算法的不足,结合帧间差分法和背景差分法,提出背景动态更新的运动检测算法。该算法能自适应背景的变化,减少由背景变化造成的误检测。构建基于FPGA的视频监控系统,在FPGA上用该算法实现了640pixel×480pixel,30帧/s视频信号流的运动目标实时检测。系统提供了分区域运动目标检测的功能。检测区域的大小、位置和个数可通过简单的按键操作进行设定。测试结果表明,系统可以实时地对进入划定区域的运动目标进行检测和闪烁告警,且资源占用较少,适合在小规模的FPGA上进行实现。     

视频监控中运动目标检测和阴影消除

由于外界环境的复杂性,视频监控中检测出的运动目标往往轮廓缺损,并伴随阴影和噪声等问题.提出了一种方法用以改善轮廓、消除阴影和噪声.该方法首先利用五帧梯度图像的差分确定运动目标的变化区域,再与背景差分法的结果相或,获取了运动目标的完整轮廓.分析了阴影在HSV颜色空间的特性,用以消除阴影,并根据噪声的分布特性去除噪声.处理结果表明,处理速度为20 ms/帧,达到实时性要求,运动目标消除了阴影和噪声,具有较强的鲁棒性.     

监控视频下的多尺度车辆检测与跟踪

车辆检测与跟踪在自动驾驶系统中起着重要的作用.针对交通监控视频中多尺度车辆目标难以检测和重叠目标容易漏检等问题,提出使用倒残差方法来改进YOLOv3的卷积层提取特征,在YOLOv3网络中增加空间金字塔(SPP)模块,获取车辆多尺度信息,并采用Soft-NMS代替非最大值抑制(NMS),减少车辆重叠导致的预测框丢失.最后...     

视频监控下利用记忆力增强自编码的行人异常行为检测

随着视频监控数据的快速增长,对大规模视频数据的自动异常检测的需求越来越大,基于深度自编码器重构误差检测方法已经被广泛探讨。但是,有时自编码器“泛化”得很好,能够很好地重建异常并导致漏检。为了解决这个问题,提出了采用记忆力模块来增强自动编码器,称为记忆力增强自编码（Memory-augmented autoencoder, Memory AE）方法。给定输入,Memory AE首先从编码器获取编码,然后将其用作查询以检索最相关的记忆项来进行重建。在训练阶段,记忆内容被更新以表示正常数据的原型元素。在测试阶段,将学习到的记忆元素固定下来,从正常数据的几个选定的记忆记录中获得重建,因此重建将趋向于接近正常样本。因此,将加强对异常的重构误差以进行异常检测。对两个公共视频异常检测数据集,即Avenue数据集和ShanghaiTech数据集的研究证明了所提出方法的有效性。     

Encoder adaptable difference detection for low power video compression in surveillance system

As a state-of-the-art video compression technique, H.264/AVC has been deployed in many surveillance cameras to improve the compression efficiency. However, it induces very high coding complexity, and thus high power consumption. In this paper, a difference detection algorithm is proposed to reduce the computational complexity and power consumption in surveillance video compression by automatically distributing the video data to different modules of the video encoder according to their content similarity features. Without any requirement in changing the encoder hardware, the proposed algorithm provides high adaptability to be integrated into the existing H.264 video encoders. An average of over 82% of overall encoding complexity can be reduced regardless of whether or not the H.264 encoder itself has employed fast algorithms. No loss is observed in both subjective and objective video quality.     

一种基于机器视觉的视频交通流检测系统

简要分析了交通流检测技术的发展现状,结合当前智能交通系统的应用需求,利用连续三帧差分的运动估计方法来构建初始背景,并采用统计打分的策略实时地对背景进行更新;同时提出了一种简单而有效的阴影消除算法以提高交通流参数检测的准确度。另外,针对现有交通流检测系统无车辆跟踪这一环节,可能导致流量多计数的问题,本文提出同时利用车辆的位置信息、颜色信息和分形维信息对车辆进行匹配跟踪的策略。大量实验证明该检测算法能快速、有效地检测出各种交通流参数,为实现交通管理的自动化奠定基础。     

视频监控系统中的行人及其面部侦测研究

采用集成H．264硬件编解码视频处理单元Hi3512来设计视频监控系统。并探讨行人目标的自动侦测问题。在对视频图像进行形态学分析的基础上,利用背景差方法实现运动目标区域的粗提取,通过阴影去除算法实现运动目标的精确定位,再利用连续均值量化变换（SuccessiveMeanQuantizafionTransform,SMQT）算法实现运动区域灰度图像的增强处理,然后利用SNoW（SparseNetworkofWinnows）分类算法实现行人及其人脸部位的侦测。实验结果表明,所采用方法能够自动检测出监控区域的行人目标及其面部信息,可有效地应用于无人值守视频监控场合。     

高清视频监控系统的检测探索

伴随着视频处理技术和计算机技术的快速发展,高清视频监控系统已经成为视频采集处理的主要方向。通过高清视频监控系统可以获取分辨率更高的图像,画面质量也更加清晰,便于后期对监控目标的查看、控制以及管理等功能。鉴于此,本文对高清视频监控系统的检测进行详细分析。     

Rapid detection of camera tampering and abnormal disturbance for video surveillance system

Camera tampering may indicate that a criminal act is occurring. Common examples of camera tampering are turning the camera lens to point to a different direction (i.e., camera motion) and covering the lens by opaque objects or with paint (i.e., camera occlusion). Moreover, various abnormalities such as screen shaking, fogging, defocus, color cast, and screen flickering can strongly deteriorate the performance of a video surveillance system. This study proposes an automated method for rapidly detecting camera tampering and various abnormalities for a video surveillance system. The proposed method is based on the analyses of brightness, edge details, histogram distribution, and high-frequency information, making it computationally efficient. The proposed system runs at a frame rate of 20–30 frames/s, meeting the requirement of real-time operation. Experimental results show the superiority of the proposed method with an average of 4.4% of missed events compared to existing works.     

Spatio-temporal segmentation for video surveillance

The automatic extraction of moving objects and construction of site models are key problems in video surveillance systems. A novel approach to segmenting moving objects from static scenes as well as acquiring background images automatically is presented. Experimental results on real video sequences demonstrate the robustness and accuracy of the algorithm