Frame grabber for image processing in ingress/egress control system

摘要

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.