具動態監控能力之3D環境即時攝影機調派系統設計與實作

Abstract

隨著安全議題不斷升溫，人們越來越渴望一套良好的監控系統來維護人身及財產的安危，而影像監控是一個最受歡迎的安全監控系統，其原因在於它可以應用於各種環境及場合，如：公司、廠房、校園及辦公室的監控等。然而，目前影像監控系統所達到的覆蓋效果，多半只針對2D平面的涵蓋，至於3D物體、空間或區域者，其可視角度及解析度，並沒有一個較精確的覆蓋方式。因此，我們希望設計一套適用於3D環境的即時影像監視系統以滿足可視角度及解析度的要求。系統所使用的攝影機具有水平、垂直及變焦功能(Pan-Tilt-Zoom Camera)，讓我們可以透過演算法來動態配置這些攝影機的焦距以及方向，以同時監控多個不同大小、位置及方向的3D物體、空間或區域，尤其針對突發性事件如：辦公室/工廠/校園火災、員工/學童異常聚集、械鬥或陌生訪客未經授權侵入等。另外，藉由效能分析指出我們所提出的演算法與其他已存在的演算法在運算上更具即時性、而且只要調派較少的攝影機就可以有更高的覆蓋率，說明我們開發的影像監控系統能在有效的時間內完成攝影機的調派，並且能夠監控較多的物體、空間或區域。

As people become more concerned regarding security issues, there is also an increasing demand on a good monitoring system to protect the safety of people or valuable properties. With the recent advance in camera technology, video surveillance becomes one of the most popular security monitoring system, since it can be applied to a variety of environments and situations, such as: companies, factories, and schools. However, most of current video surveillance systems only adopt simple 2D representation of camera’s field of view, while in reality, 3D objects, spaces or areas are involved, which cannot be covered precisely using a simple 2D model. Therefore, this research study aims to design a real-time video surveillance system that is more suitable for 3D environment given a certain viewing angle and resolution requirement. Cameras used in this system have horizontal, vertical and zoom function (Pan-Tilt-Zoom Camera), so that we can dynamically configure the camera focal length and direction through algorithms, to simultaneously monitor a number of objects, spaces or areas with different size, location and direction. The system can be applied to monitor emergency events, for example Office / factory / campus fire, unexpected staff / students gathering or fighting. It can also monitor unauthorized entry from visitors/strangers/burglars. In the performance evaluation section, we demonstrate the efficiency of our algorithm compared to other existing algorithms, by using less deployed cameras but can achieve higher coverage ratio, proving that our developed video surveillance system can accomplish the deployment of cameras within the valid period of time and monitor more object, space, and area.