Hardware Design And Implementation Of Identity Document Information Acquisition Instrument Based On CIS

At stations,dock,airports,hotels,etc.,it is often necessary to authenticate the holder based on the identity document.In the authentication process,it is first necessary to collect the identity document image and read the electronic information of the identity document,so as to realize automatic information reading,identity document verification and personal identification.In this process,the acquisition of image information and electronic chip information is the key link,but the traditional identity document information collection equipment has large equipment size,supports few types of identity documents and collect few information.Therefore,this paper designs the hardware system of multi-class identity document comprehensive information acquisition equipment.Firstly,this paper analyzes the technical requirements of the hardware system of the identity document information acquisition equipment,and designs a set of hardware technology scheme based on CIS(Contact Image Sensors).This paper designs the interface circuit of the image sensor and solves the problem of CIS timing control and analog data quantization.The card reader which supports multiple identity documents is adopted to solve the problem that traditional identity documents information acquisition equipment supports less types of identity document and has complicated structure.Aiming at the problem of unstable transmission speed of USB(Universal Serial Bus),dual cache design is adopted in the hardware to improve the stability of data transmission.Based on VHDL hardware programming language,realized CIS data acquisition control,AD converter configuration and sampling control,data splicing and real-time transmission;Aiming at the problem of vertical stripe in image,an image correction algorithm which can be applied to FPGA(Field Programmable Gate Array)is designed by analyzing CIS working characteristics and noise sources.Aiming at the problem that the ultraviolet image features collected are not obvious,an RGB(Red,Green and Blue)three-channel image enhancement method is designed and implemented to quickly highlight the ultraviolet anti-counterfeiting features of identity documents in the FPGA.After the completion of the design of the hardware system of the identity document information acquisition instrument,the system is combined with the software and algorithm for debugging and testing.The test results show that the hardware can work stably,can collect the white light,infrared and ultraviolet images of identity documents,and can support a variety of identity document chip information reading,and each function and performance can meet the expected requirements.