基于混合高斯运动检测模型与多特征的烟雾识别算法

为了有效克服复杂环境下动态、静态疑似烟雾物体的干扰,实现对烟雾的实时准确检测,提出基于混合高斯运动检测模型与多特征分析的烟雾识别算法。首先应用优化的混合高斯运动分析模型对视频图像序列进行运动区域提取,然后依据烟雾的颜色特性、形状不规则性及面积扩散特点,对提取的疑似烟雾运动区域进行分析与筛选,从而判定出其是否为烟雾。实验结果表明:该算法可实时提取视频中的烟雾区域,并有效剔除疑似烟雾区域的干扰,具有良好的烟雾识别能力。

一种新的运动目标快速检测分割方法的研究

运动目标的检测与分割是视频分析的重要内容。对静态背景中的运动对象的检测方法进行了研究,针对基于混合高斯模型的背景减除法无法解决的"鬼影"和算法复杂耗时的问题,提出了一种新的基于帧差运动边缘检测的方法。实验证明,该方法可以在复杂背景下准确地获得运动对象边界,大大提高检测速度,同时有效消除背景光照变化及个别景物扰动带来的干扰。采用模板填充算法分割运动目标,并通过数学形态学滤波去除运动区域内的噪声点和填补空洞,获得完整理想的运动对象区域。

监控视频中运动目标的自动检测、跟踪和提取

为了能够从监控视频中快速准确地分析运动目标,文章提出了一种新的运动目标自动检测、跟踪和提取方法。首先通过混合高斯模型背景差分法获得运动目标初始二值轮廓。然后结合Kalman滤波和Blob匹配法跟踪物体的运动轨迹,并用矩形框架标记图像序列中的运动目标。最后传递矩形参数,采用迭代算法实现最优化分割,对运动目标进行准确提取。实验结果表明,该方法具有较高的鲁棒性和准确性。

基于运动目标特征的关键帧提取算法

针对运动类视频特征不易提取且其关键帧结果中易产生较多漏检帧的问题,提出基于运动目标特征的关键帧提取算法。该算法在强调运动目标特征的同时弱化背景特征,从而防止由于运动目标过小而背景占据视频画面主要内容所导致的漏检和冗余现象。根据视频帧熵值将颜色变化明显的帧作为部分关键帧,对颜色未发生突变的帧根据运动物体的尺度不变特征变换(SIFT)获得帧内运动目标的特征点;最后分别根据帧熵值及运动物体SIFT点分布提取视频关键帧。实验表明该算法所得关键帧结果集不仅漏检率较低且能够准确地表达原视频内容。

Adaptive moving target detection algorithm based on Gaussian mixture model

In order to enhance the reliability of the moving target detection, an adaptive moving target detection algorithm based on the Gaussian mixture model is proposed. This algorithm employs Gaussian mixture distributions in modeling the background of each pixel. As a result, the number of Gaussian distributions is not fixed but adaptively changes with the change of the pixel value frequency. The pixels of the difference image are divided into two parts according to their values. Then the two parts are separately segmented by the adaptive threshold, and finally the foreground image is obtained. The shadow elimination method based on morphological reconstruction is introduced to improve the performance of foreground image＇s segmentation. Experimental results show that the proposed algorithm can quickly and accurately build the background model and it is more robust in different real scenes.

An efficient approach for shadow detection based on Gaussian mixture model

An efficient approach was proposed for discriminating shadows from moving objects. In the background subtraction stage, moving objects were extracted. Then, the initial classification for moving shadow pixels and foreground object pixels was performed by using color invariant features. In the shadow model learning stage, instead of a single Gaussian distribution, it was assumed that the density function computed on the values of chromaticity difference or bright difference, can be modeled as a mixture of Gaussian consisting of two density functions. Meanwhile, the Gaussian parameter estimation was performed by using EM algorithm. The estimates were used to obtain shadow mask according to two constraints. Finally, experiments were carried out. The visual experiment results confirm the effectiveness of proposed method. Quantitative results in terms of the shadow detection rate and the shadow discrimination rate(the maximum values are 85.79% and 97.56%, respectively) show that the proposed approach achieves a satisfying result with post-processing step.

A robust system for real-time pedestrian detection and tracking

A real-time pedestrian detection and tracking system using a single video camera was developed to monitor pedestrians. This system contained six modules: video flow capture, pre-processing, movement detection, shadow removal, tracking, and object classification. The Gaussian mixture model was utilized to extract the moving object from an image sequence segmented by the mean-shift technique in the pre-processing module. Shadow removal was used to alleviate the negative impact of the shadow to the detected objects. A model-free method was adopted to identify pedestrians. The maximum and minimum integration methods were developed to integrate multiple cues into the mean-shift algorithm and the initial tracking iteration with the competent integrated probability distribution map for object tracking. A simple but effective algorithm was proposed to handle full occlusion cases. The system was tested using real traffic videos from different sites. The results of the test confirm that the system is reliable and has an overall accuracy of over 85%.

Unusual Event Detection and Prediction in Real-life Scenes

In this paper,we consider unusual event detection problem in a novel viewpoint and provide an algorithm to solve the problem.The actions or events in the scene is usual or not will eventually be reflected on the changes of some basic features.We summarize these basic event features and propose special representation for each of them.Thus we can model these features in a uniform mode using adaptive Gaussian mixture model.Supervised and unsupervised unusual event detection algorithm can be designed to fit various situations based on this model.The superiority of our model is that it can detect unusual event automatically without to know the determinate model of unusual events.In conclusion,we provide two applications to verify the effectiveness of our model.