实际生产中系统的设计.doc

实际生产中OCR系统的设计 摘 要 本课题研究了光学字符图像的计算机识别问题。字符根据书写方式的不同，分为印刷体字符和手写体字符。系统针对每种字符各自的特点，通过对字符的预处理，提取字符本身特征，然后运用特定的识别算法，实现了字符图像的自动识别。整个系统包括图像采集、图像预处理、特征提取与字符识别四个部分。 对于印刷体字符，在对字符进行了图像预处理后，采用网格特征和交叉点特征相结合的方法作为其字符特征，建立字符标准特征库。 印刷体字符采用模板匹配算法实现了字符的识别，利用待识别字符与字符标准特征库相比较，把待识别字符识别为与其特征向量的欧氏距离最小的特征向量所代表的标准字符。 系统由NI公司的虚拟仪器软件LabVIEW及图像处理工具包IMAQ Vision Builder开发，实现了图像的采集、预处理、特征提取和字符识别等功能。该系统充分发挥了虚拟仪器的开发周期短，编程简便，代码复用率高，操作简单，界面友好，可靠性高等优点，节省了系统成本，提高了效率。 关键词：字符识别，IMAQ Vision Builder，虚拟仪器 OCR Systems Design In The Actual Production ABSTRACT In this paper the problem of computer recognition to the character image is studied.According to the style of writings,the characters are divided into two forms:printing characters and handwriting characters.Based on every characteristic of the two styles,system realizes the function of image pre-processing,characteristic extraction and character recognition.So the whole system is divided into four parts,image collection module,image pre-processing module,characteristic extraction module and character recognition module. For the printing characters,first, the system completes the image processing and then extracts the combined characteristic of the net characteristic and the intersection characteristic.Basing on these a standard characteristic database of characters is established.The recognition arithmetic of printing character adopts template matching,which compares the character with the standard characteristic database and recognize the character as the nearest Euclid distance standard character in the standard characteristic database. The software development adopts the NI Companys Virtual Instrument LabVIEW and IMAQ Vision Builder tool.The software realizes the function of image collection,image pre-process,character extraction and character recognition.It has the merit of short period of impoldering,convenient programming,high repeated using rate,easily operation,friendly interface,high reliability and so on. Keywords：character recognition,IMAQ Vis