License plate recognition technology for toll violation enforcement

The equipment used for the Fastoll integrated toll collection system was the RIA-300 license plate reader, loaned by the 3M company. This is a compact stand-alone automatic system. The principal elements of the equipment are a strobe light source, a shuttered video camera and an image processor. The shuttered video camera is used to record a still frame of each vehicle´s license plate. The processor module is a 68020 based image processor that controls the system and performs character recognition. It receives an RS-170 still-frame video signal from the camera, which is stored in memory in a 640×512 array of eight-bit values. If the software in the microprocessor-based controller locates a license plate within the digitized image, character recognition algorithms are used to read the plate. The testing and appraisal of the system are presented