DIGITAL SURVEILLANCE SYSTEM WITH PRE-EVENT RECORDING

An image recording system and method for use with a surveillance system having at least two cameras provides true pre-event recording for multiple input sources to improve video on demand storage control. More specifically, an image recording subsystem is connected to the cameras for receiving generated video images, and storing the received images in a temporary storage device having a storage capacity large enough to store video images generated over a predetermined period of time. The image recording subsystem is arranged to continuously record video images into the temporary storage device such as a cache memory, and in response to the occurrence of a triggering event, subsequently record the temporarily stored video images into a long-term storage device for later retrieval. The image recording system is arranged to determine the occurrence of overlapping triggering events, and automatically “rewind” the sequential long term storage process so that any images associated with an earlier triggering event but occurring in time after a later triggering event that have already been stored to long term storage are properly reordered to occur after any earlier occurring images associated with the later triggering event.