Design Of High-performance CMOS Image Acquisition System

Traditional CMOS image sensor are limited by processes,there are some shortcomings in terms of speed,resolution,dynamic range,and readout noise.The new scientific CMOS image sensor uses a kind of new manufacturing process,in these areas have better performance,and it provides a new direction for the development of high-performance image acquisition systems.It has become an indispensable research tool in military,aerospace remote sensing and medical field.This paper use Fairchild company scientific CMOS image sensor CIS2521 to design a set of high-performance,small size,low power image acquisition system.In this paper the main work are:Firstly,this paper designs the overall scheme of the system.It analyzes key modules such as acquisition,control data caching and data transmission and it also finished the selection of the device.It established the system design program of the sCMOS image sensor + FPGA control chip + DDR2 SDRAM cache chip + Camera Link high-speed transmission interface.By analyzing of hardware circuit,it designed the system hardware program,and it also designed the hardware circuit schematic.Then,based on the hardware circuit,it designed the FPGA drive software program,the software can complete the CMOS image sensor power control,clock management,register configuration and other function,the software can drive CMOS image sensor to work and output image data.Finally,the software designed in this paper can be completed the real-time online processing function.The data processing module converts the gray code into a binary number,it also has dark current cancellation and image sensor nonuniformity correction function.Compared with the traditional two-point correction method,the third-order polynomial fitting algorithm has higher precision in terms of correcting images.The maximum resolution of the image acquisition system is 2560*2160,and the frame rate can reach 87 fps in the Rolling Shutter mode.The maximum transmission rate can reach 630 MBps.The imaging tests show that the design of the high-performance image sensor can drive the image sensor work properly.