光电纸币清分系统的图像处理

【作者】 蒋雁飞；

【导师】 叶玉堂；

【作者基本信息】 电子科技大学 ， 光学工程， 2006， 硕士

【摘要】 纸币清分机是一种集光机电磁于一体的高端金融现金处理设备，其主要功能是对纸币进行面额、面向、新旧程度的识别，以满足挑选适合ATM取款机纸币、代替人工高效地选择可再流通的纸币等要求。随着模式识别理论在近三十年内获得高速的发展，通过光电图像来识别纸币的计算机技术于20世纪90年代开始陆续出现，并在纸币清分机上得以应用，使识别率进一步提高。早期采用数字图像识别技术的清分机由于受到芯片处理能力的限制，存在运算能力低下、机械结构复杂、体积庞大等缺点。21世纪初随着高性能数字信号处理器的出现，使清分机小型化、高速度的目标成为可能。为了打破国外清分机对我国金融市场的垄断，以最新的芯片技术研发性能优良且价格合理的清分机成为国内高端金融设备研发商的重要目标。 本文首先综述了当前国内外纸币清分机的研发现状，构建了一套由图像处理电路(包括主运算DSP芯片TMS320C6414和外扩存储器)、输入通路(包括A／D转换器、缓冲器)、逻辑控制器、调试端口(JTAG，Joint Test Action Group联合测试行动小组)、电源管理等各部分综合而成的智能纸币清分机光电图像处理平台，并对包括接触式图像传感器(CIS，Contact Image Sensor)等重要器件进行了选型分析。 系统的核心是TI公司的TMS320C6414 DSP芯片，通过CPLD (ComplexProgrammable Logic Devices复杂可编程逻辑器件)逻辑控制，利用该DSP强大的数据处理能力、高达1024 KB的内部Cache／RAM结构以及丰富的集成外设资源，能完成纸币图像处理算法的各项任务，满足清分机苛刻的实时性要求。系统硬件具有两个在该领域的创新点，一是首次将高性能DSP芯片TMS320C6414应用到清分机系统上，通过EMIF(External Memory Interface，外部存储器接口)进行大容量存储空间的扩充，保证了识别人民币需要的大数据容量要求。二是根据图像传感器的四通道输出结构，设计了相应的拼接式数据采集模式，保证了数据采集的完整性。这两个创新点结合起来，使清分机变得更轻巧，速度更快，性价比更高。此外，还研究了系统的程序加载过程，编写了适合本系统的FLASH存储器烧写程序及程序自动加载程序。更多还原

【Abstract】 Currency sorter is an advanced financial processing device integrated with optics, mechanics, electronics and magnetics. Its main function is to recognize the denomination and face direction of the bills and distinguish the newer bills from the older ones. Henceforth, currency sorter may satisfy the general operation on ATM such as drawing out bills and the selection of reusable bills automatically. With the high-speed development of the theory of pattern recognition in the last thirty years, the computer technology of bill’s photoelectric image recognition which used on currency sorter to improve its recognition ratio, has appeared in succession in the last decade of 20 century. The early currency sorter which used the digital image recognition technology is restricted by capability of CPU. They have some shortages: poor calculation skills, complex mechanism, bulky machinery and so on. With the invention of high-performance DSPs, the goal that minimize and quicken current sorter simultaneously has became more feasible. To break monopolization of foreign currency sorter, the advanced financial facility company instituted an important goal to research and develop currency sorter which used the streamlined CMOS chip technology and it has both good performance and low price.Firstly, the current status of the bill sorter development is summarized, then a system has been established which consists of five parts, that is, image process portion(including TMS320C6414 and memories),input channel(included contact image sensor, analog-digital converters and buffers),logic controller, debugger(JTAG) and power manager.The key component of this system is the DSP chip TMS320C6414 made in TI. The logic is controlled by CPLD. This DSP owns powerful capabilities of processing datum, 1024 KB internal Cache/RAM structure and abundant resource of integrated peripherals. It can execute varieties of tasks, which are required by bill image processing algorithm, and is fit for the rigorous demand of real-time. There are two innovations in the hardware system in currency sorter field. One of the innovations is that the TMS320C6414 is applied on currency sorter system for the first time. This project更多还原