Abstract: The present invention relates to a backup system for digital surveillance system comprising video cameras, main server(s), networking facilities, a data-switching system, management server(s), backup server(s) and a central control station of an existing surveillance system, wherein a plurality of the video cameras connect to the main server(s); the microprocessor(s) of the main server(s) is installed with software which compresses recorded backup images in real time and the main server connects to the networking facilities; the data-switching system connects to the networking facilities and the management server(s); the management server(s) connects to the backup server(s) and the central control station; the microprocessor(s) of the management server(s) is installed with software which continuously monitors the operation of the main server(s) via the networking facilities, directs the backup server(s) to take over the function of the main server(s) to compress and backup data when malfunctioning occurs, and

Abstract: The present invention relates to a surveillance system for application in taxis comprising hidden video camera(s), a server, wireless networking facilities, an emergency switch and a central monitoring station in a taxi. The circuit board of the server has a microprocessor installed with software which automatically compresses temporary image backup files and transmits them by long-distance real time transmission via the wireless networking facilities to the central monitoring station for surveillance and permanent backup storage. The present invention effectively prevent offenders from damaging or stealing recorded images stored inside the taxis and destroying evidence of crime.