| 摘要 |
A surveillance system comprises a number of video cameras (12) connected to a central control (10). Video information is converted to digital format and stored in a disc drive (36). A comparator (42) is used to detect movement within the field of view of the cameras (12), and detection of movement causes the relevant images to be retained, the stored data otherwise being discarded. Stored images can be viewed on a domestic television set by being retrieved via a D/A converter (46) and a modulator (47). |
