CAMERA CONTROL METHOD FOR VEHICLE ENTRAMCE CONTROL SYSTEM
First Claim
1. A camera control method for a vehicle entrance control system comprising the steps of:
- a) calculating an average value of image brightness and writing multiple parameters of exposure time and gain level that match with a calculated average brightness value in a lookup table to a camera control register;
b) comparing the average brightness value with a threshold of strobe operation and comparing acquired exposure time and gain level parameters with preset maximum limitations;
c) turning on a strobe if the acquired exposure time and gain level parameters are higher than the preset maximum limitation and the average brightness value is lower than the strobe operation threshold; and
d) adjusting the exposure time and gain level if the acquired exposure time and gain level parameters are lower than the preset maximum limitation and the average brightness value is higher than the strobe operation threshold.
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Accused Products
Abstract
This development is about the camera control method for a vehicle entrance control system. In detail, it is about the applying variable exposure time and gain level per image frames that are captured through a CCTV camera of vehicle entrance control system. The entire control is done through 4 steps. The first step is to calculate the average value of image brightness and write the multiple parameters of exposure time and gain level that match with the calculated average brightness value in the lookup table to a camera control register. The second step is to compare average brightness value with the threshold of strobe operation and compare acquired exposure time and gain level parameters with the preset maximum limitations. The third step is to turn on strobe if the acquired exposure time and gain level parameters are higher than preset maximum limitation and average brightness value is lower than strobe operation threshold. The fourth step is to adjust exposure time and gain level if the acquired exposure time and gain level parameters are lower than preset maximum limitation and average brightness value is higher than strobe operation threshold. This development is to maintain a certain brightness level of images by controlling exposure time and gain level on a camera and turning on and off a strobe, which is proven the most adequate brightness for license plate recognition.
42 Citations
18 Claims
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1. A camera control method for a vehicle entrance control system comprising the steps of:
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a) calculating an average value of image brightness and writing multiple parameters of exposure time and gain level that match with a calculated average brightness value in a lookup table to a camera control register; b) comparing the average brightness value with a threshold of strobe operation and comparing acquired exposure time and gain level parameters with preset maximum limitations; c) turning on a strobe if the acquired exposure time and gain level parameters are higher than the preset maximum limitation and the average brightness value is lower than the strobe operation threshold; and d) adjusting the exposure time and gain level if the acquired exposure time and gain level parameters are lower than the preset maximum limitation and the average brightness value is higher than the strobe operation threshold. - View Dependent Claims (2, 3, 4, 5)
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6. A method of controlling a camera for a recognition system, comprising:
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calculating an average brightness of a reference image captured by the camera, the camera having a plurality of operational parameter values; retrieving from the camera the operational parameter values corresponding to the captured reference image, including a reference exposure time value and a reference gain level value; and generating an improved second image based upon a comparison of the average brightness, the reference exposure time value, and the reference gain level value relative to predefined threshold values of the respective ones of brightness, exposure time, and gain, the operational parameter values being adjusted in response thereto for the capture of the second image. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification