The Research On CCD Image Acquisition And Edge Detection System Based On USB2.0

With the development of the times,the acquisition and processing of digital image are getting widely used in fields such as scientific research,industrial and agricultural production,medical and health services,public security and so on. However,it can not work well unless there is a high-speed data acquisition system. Meanwhile,it is also the basis of image processing,compressing and recognizing. Therefore,the research on image acquisition system is very important and has great value.At present,most of the image acquisition systems transfer data to PC through a computer interface and complete their work with the help of computer's high-speed computing ability and large storage capacity.However,traditional computer interfaces have the disadvantages of high cost and inconvenience in dealing with image data transferring,so it is necessary to replace them with some new interface.In the field of digital image processing,edge detection has always been a popular and difficult subject.Due to the existence of the classic "dilemma",although many experts and scholars have put a lot of time and energy into it,it still has not been satisfactorily resolved.Against that background,this paper introduces a scheme of the data acquisition and processing system based on USB2.0.The system takes area array CCD image sensor as data source,and consists of data transferring module,real-time displaying module,edge detecting module and saving image module.In general,research and development works involved in this paper can be concluded as following aspects:(1) Gave an overview of development with CCD image sensor and data acquisition system as well as the present situation in research of edge detection.On this basis,the overall structure and design scheme of the system were proposed.(2) On the important concepts of the USB protocol,such as USB transfer type,USB descriptor and USB device request,it gave a brief introduction.Then analyzed the output synchronous timing signal of the signal processing chip special for area array CCD and characteristics of CY7C68013A,then developed the USB firmware based on Slave FIFO mode.(3) Studied the WDM model under Windows platform,analyzed its hierarchy structure and composition,and then designed the special driver for CY7C68013A in accordance with the USB device driver development procedure.(4) Proposed an edge detection algorithm based on wavelet analysis theory,it combined multi-scale analysis ability of cubic B-spline function with direction feature of directional derivative,thus can effectively suppress noise and locate edge.(5) Based on the analysis of application's function,it gave a clear module division and implemented them in VC6.0,including data acquisition module,real-time displaying module,edge detection module and saving image module.