Abstract: An HOV enforcement system comprises roadside imaging units connected over a network to a central processing center. The roadside imaging units include Ethernet cameras with integrated vehicle detectors, night-time lighting, and image servers. The central processing center includes a central server with license plate reading and vehicle matching software, storage and databases, and review staff to issue bills and citations.

Abstract: An HOV enforcement system comprises roadside imaging units connected over a network to a central processing center. The roadside imaging units include Ethernet cameras with integrated vehicle detectors, night-time lighting, and image servers. The central processing center includes a central server with license plate reading and vehicle matching software, storage and databases, and review staff to issue bills and citations.

Abstract: In a vehicle time-of-entry and time-of-exit system, the passing of a vehicle through an entrance generates a “trigger-t0” signal. An entrance video camera provides realtime images of entering vehicles. The trigger-t0 signal causes one video frame of the image of vehicle to be stored or “frame-grabbed” in an entrance subsystem. A time-of-entry clock-time signal is used to time-stamp the image which is then forwarded on a connection to a matcher. The passing of a vehicle through an exit generates a “trigger-t1” signal. An exit video camera 116 provides realtime images of exiting vehicles. The trigger-t1 signal causes one video frame of the image of vehicle to be stored or “frame-grabbed” in an exit subsystem. A clock-time signal is used to time-stamp the image which is then forwarded on a connection to the matcher. A output automatically provides a length-of-stay for each exiting vehicle according to its time-of-entry.

Abstract: A vehicle video imaging system comprises a white-light LED array for illuminating retro-reflective painted parts of a vehicle's license plate, a powerful flash with a visual spectrum cutout filter and a polarizing filter for illuminating any non-retro-reflective license plate paint and the vehicle itself. A video camera with a polarizing filter turned 90° relative to the one in front of the flash receives the illuminated image of the vehicle and its license plate. The retro-reflective paint of a license plate will return polarized light as it is received, so the white-light LED array will provide all the illumination needed by the camera to get a good high-contrast picture of the license plate. The polarizing filters will combine to block out most of the light from the flash that was returned still-polarized by the retro-reflective-paint license plate.