Skip navigation.
Home
Vision-based System
Video Surveillance

Video Surveillance

VISUAL SURVEILLANCE SYSTEMS WHICH CAN UNDERSTAND OF HUMAN ACTIONS INTELLIGENTLY IN REAL-TIME

Anti-Terrorism has been a global issue and video surveillance has become more and more popular in public places such as elevators, banks, airports and squares. The fundamental problem is the understanding of human actions intelligently in real-time. We present a low-cost PC based real-time surveillance system to model and analyze human actions based on learning by demonstration. By teaching the system the differences between normal and abnormal human actions, the computational models built inside the trained machines can automatically identify whether the newly observed behaviors require security interference.

In our project, we present two approaches to detect abnormal behaviors. The first one employs Principal Component Analysis for feature selection and Support Vector Machine for classification of human behaviors. The feature selection method is based on the border information of four consecutive blobs. The second approach computes optical flow to obtain the velocity of each pixel for determining whether a human behavior is normal or not. Both algorithms are successfully implemented in crowded environments for detecting the human abnormal behaviors, such as:

a) running people in a crowded environment;
b) bending down movement while most are walking or standing;
c) a person carrying a long bar;
d) a person waving hand in the crowd.

Key Investigators: Prof. Yangsheng Xu, Weizhong Ye, Xinyu Wu, Zhi Zhong, Xi Shi
Related contents
  目前,反恐已经成为一个全球性的课题,越来越多的录像监控系统安装在公共场合,例如电梯、银行、机场和广场。录像监控系统中最重要的问题就是如何实时并智能地去理解人的行为。通过学习,我们研制的实时录像监控系统利用低配置的电脑就可以对人的行为进行建模和分析。只要告诉系统正常行为和异常行为的区别,系统通过其内部经过训练的机器模型,就可以自动地判断新的行为是否需要安全介入。
  在本项目中,我们提出了两种方法来检测异常行为:第一种方法是运用主元分析法来进行特征选择,并采用支持向量机来对行为进行分类;第二种方法是利用光流的方法来得到每个象素点的速度,继而判断人的行为是否正常。两种方法都被成功地运用到复杂环境下的异常行为检测这个问题上,例如:
  a)有人在拥挤的环境中跑动;
  b)有人蹲下,而其他大多数人站立或在走动;
  c)有人扛着一个很长的竿子;
  d)有人在拥挤环境中挥手。