Abstract: A frame grabber (10) used in a security system monitoring a secure area. The frame grabber converts video images from a camera (T) to a digital format and records the converted images (I). In response to an alarm which occurs when a person attempts an unauthorized entry into the secure area, the frame grabber automatically halts the recording and commences playback of previously recorded images. The playback comprises a continuous loop (L) of images which are displayed on a video monitor (M). An operator of the security system can halt the playback at any image in the loop so to attempt to identify the person. In determining which image to display, the operator can move both forward or backward through the loop.

Abstract: An ingress/egress control system (10) controls passenger (P) flow into and out of an airport concourse. Enplaning passengers pass through an entrance portal (18) on their way to an airplane gate. A security screen (22) screens each person passing through the portal for the presence of prohibited items and identifies any person suspected of carrying such an item. A secondary portal (50) is located downstream of the first portal. A visual display system (52) responds to an indication from the security screening to route a suspected person from the first portal to the secondary portal, for further screening to determine if the person is carrying a prohibited item, while providing a different display to passengers passing the security screen so they can enter the concourse. A separate, exit portal (64) is provided for deplaning passengers exiting the concourse.