Research On The Quality Examination Of Cambered Commodity Barcode On Binocular Vision

Commodity barcode is the"identity card"of commodities,which is indispensable in the informatization development of commodity circulation.The printing quality of commodity barcode affects the circulation efficiency and settlement safety of commodities.Therefore,the state has promulgated a series of printing quality standards and specifications for commodity barcode,and domestic barcode inspection agencies at all levels shall inspect and supervise the quality of barcode.At present,the existing examination equipments can accurately complete the quality examination of commodity barcode,which is printed on the planar packaging,but there are no equipments and technologies to meet the requirements for commodity barcode,which is printed on the cambered packaging.In this regard,this paper takes EAN-13 barcode as the research object,and studies the quality examination technology of cambered commodity barcode.This project uses binocular vision system to examine the quality examination of cambered commodity barcode,including binocular commodity barcode image acquisition module and binocular commodity barcode image analysis and calculation module(software).I am mainly responsible for the latter research,and the main work is divided into the following three parts:First,binocular camera calibration.This is the initialization of the system,which is completed when the system is built.Firstly,the calibration graph is designed,and the binocular acquisition device is used to obtain the left-eye and right-eye calibration images respectively.The corner points in the images are taken as feature points,and the Tsai linear calibration method based on coplanar points is used to calibrate the left and right cameras respectively,and the internal and external parameters of the cameras are obtained.Then the stereo calibration of binocular camera is completed by the relative relationship between left and right camera coordinate systems,and the rotation matrix and translation vector between two cameras are obtained.The above calibration datas provide calculation parameters for 3D reconstruction of cambered commodity barcode image.Second,image processing of binocular commodity barcode.After the binocular camera calibration,the quality examination of commodity barcode can be carried out.Firstly,the binocular acquisition device is used to collect the images of the cambered commodity packaging,and the left-eye and right-eye barcode images are obtained.Then,the barcode region in the image is extracted by the gradient difference calculation,morphological processing and contour tracking of two images.Then,for the feature points in the left-eye image,the corresponding matching points in the right-eye image are calculated by the epipolar constraint.Finally,combined with the calibration parameters,which are obtained by binocular camera calibration,the three-dimensional reconstruction of the cambered commodity barcode image is completed by space coordinate transformation,and the planar commodity barcode image is restored.Third,the analysis and calculation of commodity barcode examination parameters.After obtaining the planar commodity barcode image,it is divided into a barcode symbol area and a numeric character area.Through analysis and calculation of these two parts respectively,a total of 13 examination parameters,which include dimensional characteristics,optical characteristics and symbol consistency of commodity barcode,are obtained.The grade of the obtained parameters are first judged according to the national standards,and then sorted according to the importance of the parameters to complete the comprehensive judgment.In the experiment,30 cambered commodity packaging samples are selected for examining.The results show that all samples can complete the quality examination,which proves the feasibility of the method in this paper.In order to further verify the accuracy of this method,1 00 planar commodity packaging samples are selected.Firstly,the traditional method is used to examine the quality of barcode and record the results,then the samples are pasted on cambered commodity packaging,and the method in this paper is used to examine the quality of barcode and record the results,finally,the results of two methods are compared.The results show that the examination results of the parameters obtained by the two methods are basically the same,and the error is very small.The conclusions obtained in the single grade and the comprehensive judgment are the same,which proves the accuracy of the method in this paper.The same cambered commodity packaging sample is placed and examined in multiple directions,and the obtained parameter examination datas are very close,which proves the stability of the method in this paper.The examination results of the method in this paper are accurate and reliable,which fills the vacancy of the quality examination of cambered commodity barcode,and is of great significance to the improvement of barcode quality examination technology.