Research On Dual-ptz-camera System

With the increase of safety awareness around the world, vision based securitymonitoring technologies have received more and more attention. The research aboutvisual surveillance system has a wide application scope. Inspired by the special visionsystem of chameleons, this thesis studies the dual-PTZ-camera system in this thesis.In this system, two pan-tilt-zoom cameras serve as a vision unit. This work is di?erentfrom most existing research in motivation, system composition and the capability thesystem can achieve.Di?erent from the vision system of human beings and most animals, chameleon'stwo eyes are very special in that they can either move independently to watch globalview or move in a cooperative way to achieve high-precision stereo vision. This abilityhelps chameleons catch preys e?ciently. In the dual-PTZ-camera system, two cam-eras are able to achieve similar functions like chameleons. The main advantages ofthis system include: (1) both large-view information and high-resolution local-viewinformation can be obtained at the same time; (2) stereo vision can be employed toobtain depth information of the scene; (3) two cameras can work in either independentor cooperative mode, etc. These advantages will benefit many visual surveillance ap-plications. As far as we know, very little relative research has been found in literature.This thesis covers some basic problems in dual-PTZ-camera system. The mainresearch contents and results of our study include the following aspects:(1) This thesis proposes a spherical stereo rectification model which can be usedfor stereo vision and representing a kind of relationship between two PTZcameras. A self-calibration approach is also presented to build this model;(2) A stereo vision framework in dual-PTZ-camera system is proposed. It can beused to obtain the depth map of the scene provided camera (pan-tilt-zoom)parameters;(3) According to the variability and controllability of camera parameters, high- resolution and wide-scope depth information can be obtained. This depthinformation is very useful for scene understanding and modeling;(4) This thesis proposes a novel framework to stabilize and complete high-spatial-resolution video using the dual-PTZ-camera system. This work can be usedfor not only improving the visual e?ect, but also gesture recognition, behaviorand gait analysis, object identification, security evidence collection, etc.(5) This thesis proposes two preliminary applications for visual surveillance toverify the advantages and abilities of the dual-PTZ-camera system.Experimental results verify the feasibility of our study. Some techniques havealready applied in the'Vessel Surveillance System on Yangtze River'(a program co-operated with the ministry of communications of PRC).