A Fast Calculation Method of License Plate Tilt Angle in Fixed Range

Abstract

The invention discloses a method for quickly calculating the inclination angle of a license plate in a fixed range. The method includes the following steps: setting the initial parameter of the angle parameter a, taking a as the center to rotate the center of the image by x degrees to the left and right, and calculating the rotated Horizontal projection to obtain projection data, respectively calculate the variance of the projection data, and analyze the variance data; if the data has an inflection point, the angle parameter a at which the inflection point appears is the inclination angle of the license plate image; if the data is a decreasing curve, the angle parameter a Carry out forward iterative calculation until the data has an inflection point; if the data is an increasing curve, perform reverse iterative calculation on the angle parameter a until the data has an inflection point; record the inclination angle of the license plate image obtained each time, and take the maximum value to update Computes the center angle parameter a to output the image angle. The invention overcomes the previous problem that all angles in a large range need to be traversed and calculated to obtain the maximum value when obtaining the large angle of the license plate, and reduces the amount of calculation.

Description

technical field [0001] The invention belongs to the field of intelligent transportation, and relates to a method for quickly calculating the inclination angle of a fixed-range license plate. Background technique [0002] In the field of intelligent transportation, with the rapid development of semiconductor technology and the continuous emergence of new calculation methods, the current intelligent transportation algorithms are gradually moving from the back-end PC equipment to the front-end. When the front-end platform remains unchanged, the algorithm efficiency is higher. The greater the amount of highly analyzable data, the more types of integrated algorithms will greatly improve the cost performance of the product. License plate recognition is the core of intelligent applications, and fast and accurate calculation of the tilt angle of the license plate plays a vital role in improving the overall performance of the license plate recognition algorithm. [0003] The traditi...

AI Technical Summary

Problems solved by technology

[0012] The disadvantage of this method is that it is necessary to traverse the parameter a to find the maximum value. Assuming that the range of the parameter a is between -30 degrees and +30 degrees, traversing with an accuracy of 1 degree requires 60 times of the above calculation

The disadvantage of this is that regardless of whether the image is tilted or not, the traversal calculation will be performed according to the parameters, which greatly reduces the system efficiency

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