| 摘要 |
This invention relates to an intruder alarm system and more particularly to an intruder alarm system using image capturing means to capture images of a reference surface device located in a surveillance area. The intruder alarm system includes image capture means for capturing images of a reference surface on a reference surface device, the reference surface having sections of different reflective characteristics. A comparator compares the contrast between the sections on the reference surface and causes an alarm actuator to actuate an alarm when the contrast is below a predetermined amount. |
