LPR Economics LPR and ETC vendors are aware of the concerns and issues of VES and the associated costs to review images. A rough set of benchmarks is that in a manual review system, each image reviewer can process approximately 100 images per hour. This includes the entering of the plate information into data fields associated with the image. How It Works 1. Image acquisition - the camera captures an analog image of the vehicle and sends the image through a digital conversion process.
All implementations have a camera that is focused to capture the rear plate area of the vehicle.
In a few implementations, the front plate area is also captured. Front plate capture is a requirement for semi-tractor trailers where only the tractor has a visible plate. Image identification - for each vehicle that goes through the lane one or more images are typically buffered temporarily in the memory of an interface board, called a frame grabber. If the lane controller identifies the vehicle as a violator, the associated images in the frame grabber are saved. Image storage - the images may be stored locally on the lane controller or transferred to the plaza system.