초록 ▼

An apparatus and method for automatically recognizing the characters on a license plate which is fixed on a vehicle. A sensor/controller device is utilized to detect whether the vehicle has reached a predetermined position for image sampling, and to release a trigger signal when the vehicle has reac

An apparatus and method for automatically recognizing the characters on a license plate which is fixed on a vehicle. A sensor/controller device is utilized to detect whether the vehicle has reached a predetermined position for image sampling, and to release a trigger signal when the vehicle has reached the predetermined position. An image processing unit is coupled to the sensor/controller device to receive the trigger signal and then to send an image-sampling instruction to an image-sampling device. The image-sampling device is coupled to the image processing unit, and samples a vehicle image including the image of the license plate in response to the image-sampling instruction. The vehicle image is converted into an electric signal by the image-sampling device, which in turn is sent back to the image processing unit. The image processing unit digitizes the electric signal, and process the digitized electric signal to estimate the position of the license plate, to determine the bounding edges of the characters on the license plate, to separate each character on the license plate, and to recognize each separated character.

대표청구항 ▼

An apparatus for automatically recognizing the characters on a license plate which is fixed on a vehicle comprising: sensor/controller means for detecting said vehicle, for determining whether said vehicle has reached a predetermined position, and for releasing a trigger signal when said vehicle has

An apparatus for automatically recognizing the characters on a license plate which is fixed on a vehicle comprising: sensor/controller means for detecting said vehicle, for determining whether said vehicle has reached a predetermined position, and for releasing a trigger signal when said vehicle has reached said predetermined position, said sensor/controller including first, second, and third pairs of photosensors respectively arranged along two sides of a vehicle driving path; an image-sampling means for sampling a vehicle image including the image of said license plate in response to said trigger signal, and for converting said vehicle image into an electric signal, wherein said sensor/controller activates said image sampling device to indicate that said vehicle has reached a predetermined position when a light path between both said first and second pairs of photosensors is interrupted, said third photosensor pair being arranged to ascertain that said license plate is not shaded by another vehicle, wherein the distance between said first and second photosensor pairs is smaller than the length of said vehicle so that when said vehicle has reached a predetermined position, both of said first and second photosensor pairs detect the presence of said vehicle; and an image processing means, coupled to said image sampling means for receiving said electric signal, for digitizing said received electric signal, and for processing said digitized electric signal to estimate the position of said license plate, to determine the bounding edges of the characters on said license plate, to separate each character on said license plate, and to recognize each separated character.