Priori analysis based iterative method for segmenting characters of licence plate

A character segmentation and license plate technology, applied in the field of intelligent transportation, can solve the problems of poor segmentation effect and high requirements for license plate positioning accuracy

Active Publication Date: 2011-10-19
HANGZHOU DIANZI UNIV
View PDF3 Cites 22 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This type of segmentation method based on prior knowledge has a certain improvement in segmentation accuracy compared with the methods proposed in literature [1]-[3], but the requirements for the accuracy of license plate location are still high, especially whe

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Priori analysis based iterative method for segmenting characters of licence plate
  • Priori analysis based iterative method for segmenting characters of licence plate
  • Priori analysis based iterative method for segmenting characters of licence plate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0071] The monitoring system provided by the present invention will be further described below with reference to the accompanying drawings.

[0072] like figure 1 As shown, an iterative license plate character segmentation method based on prior analysis includes:

[0073] (1) Normalize the license plate image, sharpen the edge and remove the noise;

[0074] (2) Use the vertical projection method to segment the preprocessed license plate image, and calculate the brightness of each character block p b (i) , the contrast of each character block p c (i) , the mean brightness of all character blocks , the average contrast of all character blocks , if the character block does not meet any of the following conditions, it is determined that the character block is illegal, and the whole character block is eliminated:

[0075]

[0076] where c b , c c The value range of is [0, 1], those skilled in the art are obtained by experimental experience, c b , c c Take the valu...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a priori analysis based iterative method for segmenting characters of a licence plate. Method comprises the following steps of: firstly, preprocessing the image of the licence plate, segmenting the preprocessed image of the licence plate by utilizing the vertical projection method, calculating the parameter of each character block, and carrying out preliminary screening according to the parameters; secondly, carrying out binaryzation on the characters processed by preliminary screening by utilizing the threshold value iteration method, calculating the priori knowledgecontained by each character block according to the standard licence plate system, and obtaining the characters processed by secondary screening; and thirdly, calculating the quantity of blocks of thecharacters processed by secondary screening, calculating the width of characters of the licence plate and the mean width of all characters under the condition that set conditions are met, and determining whether ultimate characters can be obtained or not according to the two parameters, or carrying projection again when the set conditions are not met. The method reduces the requirement on positioning accuracy of the licence plate, overcomes the adverse effects due to a complex background, eliminates the common segmentation results of conglutination, breakage and the like of the other methods,and further improves the accuracy of segmentation.

Description

technical field [0001] The invention relates to the field of intelligent transportation, in particular to an iterative license plate character segmentation method based on a priori analysis. Background technique [0002] License plate recognition is an important part of modern intelligent transportation system, and character segmentation is a key link in license plate recognition. Due to the fixed format of license plates, template matching has been considered as the best character segmentation method, such as literature [1] Li Zhanbin. Research on license plate recognition technology in non-stop toll collection system [D]. Qingdao: Ocean University of China, 2005. However, the template matching method has extremely high requirements on the image quality of the car body containing the license plate, so the localization and segmentation accuracy is low. As researchers have carried out a lot of research on the method of license plate character segmentation, according to the c...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): G06K9/34G06K9/00
Inventor 张桦郭燚平孙志海周文晖戴国骏
Owner HANGZHOU DIANZI UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap