Character segmenting method based on horizontal projection and connected domain analysis

Abstract

The invention relates to fields of a vehicle plate character segmenting method based on horizontal projection and connected domain analysis and pattern recognition. The method comprises the following steps of: 1) locating a vehicle plate subimage; 2) computing the optimal threshold value of the subimage; 3) binarizing the image to obtain a binarized image; 4) rotating the binarized image at an optimal angle; 5) performing slant correction on the rotated image; 6) performing horizontal projection on the binarized image; 7) performing connected domain analysis on the binarized image to obtain a character block; 8) verifying the character block by using priori knowledge and removing a false character block; 9) performing character segmentation by combining the horizontal projection in the step 6) and the connected domain result in the step 7) so as to obtain the horizontal position of each character; 10) computing an upper border and a lower border of the vehicle plate character according to the binarized image in the step 5); 11) computing each border of a character rectangle according to the upper border and the lower border and the central position of the character; and 12) performing fine adjustment according to a horizontal projection curve to obtain a character-segmenting result. By the method, the segmentation of the vehicle plate character is reliable and stable, the resistance to image noise and interference is high, and the segmenting efficiency is high.

Description

【Technical field】 [0001] The invention relates to the field of pattern recognition, in particular to a license plate recognition method. 【Background technique】 [0002] Intelligent Transportation System (ITS) is the frontier of transportation science and technology in the world. It is an informatization, intelligence and socialization formed by transforming the traditional transportation system with advanced electronic technology, information technology, sensor technology and system engineering technology. new transportation system. The license plate number as the identity information of the vehicle is one of the key information that the intelligent transportation system must collect, so the license plate recognition has become a core technology of the intelligent transportation system. This technology refers to that the computer automatically analyzes and searches the content in the images or videos captured by the camera, locates the area where the license plate is locate...

AI Technical Summary

Problems solved by technology

However, in the case of degraded image quality, image noise interference will be introduced into the horizontal projection curve of the license plate area

In this case, the horizontal projection curve is "contaminated" data, and the accuracy of calculating the character position and its spacing information from the horizontal projection curve will naturally decrease

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