Design And Implementation Of Image Acquisition And Processing System Based On CMOS Sensor

In recent years,with the rapid development of image acquisition system,image acquisition system is gradually integrated into the field of intelligent automation,and step by step into people's lives.CMOS image sensor is widely used in the field of image acquisition system because of its relatively low cost,and low power consumption.With the development of technology,the resolution,image quality,speed and other performance parameters of CMOS image sensor are gradually improved.The requirements of power supply,transmission and control in the hardware design of image acquisition circuit are becoming more complex,and the problem of signal integrity is gradually prominent.And CMOS image sensor is limited by its analog amplifier manufacturing process and imaging principle,in low illumination or high temperature environment,there will be corresponding image quality problems.This paper is to start mainly from the signal integrity and power supply problems in the design process of image acquisition system,introduces the main design steps of the hardware part of the image acquisition system and the corresponding solutions.At the same time,aiming at the original image output by high-speed CMOS sensor,the embedded image preprocessing method based on FPGA is adopted to improve the performance of the image acquisition system.CMOS image sensor is sensitive to power supply.Unreasonable design parameters of power supply will lead to abnormal operation of image sensor.This paper first analyzes and designs the whole power supply part of the acquisition system,improves the power quality and optimizes the power distribution mode from the premise of reducing the hardware design complexity and cost.This paper analyzes the power supply principle of Poe based on flyback switching power supply,and describes the calculation and selection of Poe power supply circuit related chips and component parameters,so as to improve the debugging efficiency and performance of Poe power supply circuit.In the aspect of signal integrity,aiming at the signal integrity problems caused by hardware design problems in limited space.The key parts of image sensor high-speed transmission interface and DDR3 high-speed interface are simulated and verified by using Hyper Lynx software,which effectively improves the quality of high-speed signal transmission in the circuit board.Finally,based on the characteristics of CMOS sensor output noise and common image preprocessing methods,combined with the existing hardware platform,a real-time improved Gaussian filtering method is proposed.This method is implemented by FPGA logic,which can realize fast and real-time image preprocessing,so as to improve the overall performance of the acquisition system.