Design Of Image Capture And Preprocessing System Based On Panoramic Stereo Sphere Vision

Panoramic vision system is a machine vision system, which can directly observe all the objects in some area in stead of mechanical rotating or scanning. It has huge development of space in application, structure designing and theoretical researching. However, this system can not measure object distance when it works, so its application has some limitations.In order to solve this problem, this paper proposes a new model of machine vision system-panoramic stereo sphere vision system.This is an embedded system which based on lens+image sensor modules+FPGA+DSP.It can observe all the objects and measure the object distance in the spherical areas.The research of panoramic stereo sphere vision system can promote the development of machine vision technology.The panoramic stereo sphere vision system is huge and complex,so this paper mainly introduces a subsystem of panoramic stereo sphere vision system-image capture and preprocessing system.This system,based on CMOS image sensor and FPGA,takes responsibility of image capture,preprocessing and display. The hardware circuit of this system consist of five modules:FPGA control module,image capture module,FPGA peripheral module,system storage module and system display module.FPGA control module uses cyclone Ⅱ series FPGA EP2C35F672C6to control each module and their communication.as the key part of image capture module,MT9V136image sensor takes the charge of image capturing.The system storage module consist of4MB Flash AM29LV320DB and64MB SDRAM K4S641632.The system display module uses TFT-LCD instead of CRT display.The software of image capture and preprocessing system is designed based on SOPC development flow.Four drive modules, Nios Ⅱsystem module,I2C configure module,image capture drive module and LCD drive module,are designed and debugged under Quartus Ⅱ9.0and Nios II EDS9.0environment.The last part of this paper introduces the key technology of image preprocessing-image filtering. After illustrating the principle of image filtering,this paper introduces the design of image median filtering and image mean filtering based on FPGA platform using verilog HDL. Specially,the desing of median filtering adopts an optimized algorithm in order to reduce numbers of comparing and improve speed of median filtering.At last,this paper analyzes application of median filtering and mean filtering and summarizes that median filtering is applicated in dealing with salt and pepper noise while mean filtering suits for gaussian noise.