Design And Implementation Of Automatic Marking System For The Answer Card Based On Image Processing

Digital image processing technology along with the popularization and application of the computer technology and network technology continues to develop.The image recognition technology is an important research direction extending from the digital image processing technology.At present,the application of digital image processing and image pattern recognition technology are also extending to all aspects,and they also have a profound impact on the aspects of the field of education examination.The disadvantages of the traditional manual marking method are becoming more and more obvious,which needs a new marking way to replace it.Online marking is a new scoring model which is produced in this context to reduce the subjective marking errors,for the purpose of implementing the principles of fairness and justice.According to the needs of computer online marking,it has a very important practical significance to research electronic processing of the answer cards and the recognition and extraction technology of objective option.Online marking has gradually been widely used in large-scale selective examination by making use of its own advantages.But the existing recognition technology of the objective questions identification of the college entrance exam is single,with the problem that the printing and the accuracy of the answer sheet is high.First of all,the concept of online marking is briefly introduced.The development of domestic and foreign online marking as well as the main function and concept of OpenCV is elaborated.Secondly,the basic theory of digital image processing and recognition field is discussed,focusing on the description of the gray scale of image,binaryzation,tilt detection,and other basic digital image processing technologies.The business process and system flow of the answer card marking system are analyzed,according to the characteristics of optical mark recognition technology which has been used in marking objective part in the examination for a long time,combining with various computer image processing methods.An image information recognition system based on optical label recognition technology is presented,and the design idea and the realization technology of the system are is described.According to digitization of the image,image preprocessing,image information acquisition and feature information processing and extraction,the key technologies which are associated are discussed.A convenient method of making the answer card by using Excel form is presented.By researching the recognition of the number of questions and then identifying answer item,the impact when the answer card pattern is changed can be avoided.Using convenience and advantages of OpenCV in VC++ programming environment,a suit of online marking system is developed,which can correctly identify the answer,examination subjects,student ID and other information.And the answer sheet does not need high accuracy requirements of printing and cutting.