An intelligent alarm system

The authors describe an alarm system which will detect and track a human moving around a scene from stationary cameras. The authors provide a summary of the system from the lower pixel based representation to the higher level edge grouping and stereo matching. Data flows from the three cameras into the initial segmentation modules before the stereo matching algorithm is applied. After stereo matching, between the three cameras, they utilise edge statistics and apply the disparity gradient limit. This allows a decision about a particular edges `goodness´ to be made. The disparity results are then extracted, considered in terms of recent frames, and analysed over time. The statistics from this module can then be used to alter the thresholds at lower levels of processing. The authors discuss calibration and accuracy, explain the reasons for using three cameras as opposed to two and give examples of the algorithms applied to trial sequences