License plate luminance contrast based camera shutter and gain composite control method

Abstract

The invention discloses a camera shutter and gain comprehensive control method based on license plate brightness contrast, which belongs to the field of intelligent vehicle information collection image processing, license plate automatic recognition and computer processing systems. Set the initial parameter setting module, initialization adjustment module, and fine adjustment module in the command module of the industrial computer; when the camera collects the vehicle image according to the trigger signal of the ground sense coil and transmits it to the industrial computer, the industrial computer initializes the camera according to the initialization adjustment module in the command module Adjust to obtain the image of the license plate area; analyze the gray features of the license plate area, make fine adjustments to determine the shutter and gain of the camera, and finally send control commands to the camera for shutter gain control, which solves the camera control problem for license plate recognition; makes the license plate The recognition technology can be applied under various lighting conditions around the clock, and the recognition accuracy rate of the license plate character recognition method can reach more than 95%, which can be widely used in traffic, public security and other fields.

Description

technical field [0001] The invention discloses a camera shutter and gain comprehensive control method based on the brightness contrast of a license plate, which belongs to the image processing technology in an intelligent vehicle information collection system and relates to the field of automatic license plate recognition and computer processing systems. Background technique [0002] In the bayonet system of urban roads or expressways, it is necessary to shoot passing vehicles around the clock and automatically recognize vehicle license plates. Since it is not possible to use supplemental lighting equipment such as flashlights that may cause danger to the driver, in order to obtain a vehicle license plate image that can be recognized, the camera must be controlled to a certain extent to achieve the goal. At present, the automatic aperture is basically used to control the incident light of the camera. This method is generally only suitable for large-scale monitoring scenario...

AI Technical Summary

Problems solved by technology

However, the technical solution of this patent document is a license plate character recognition method that combines Laplace transform, region growing method and license plate prior knowledge, which is completely different from the technical route of the present invention.

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