Research Of SOC System For Real Time Video Image Restoration

The importance of video image information has been penetrated into people's daily life,has become one of the most important information media of communication between human and the outside world.With the development of multimedia technology,the image processing technology is becoming more and more important.In some special occasions,the image signal in the process of generation,transmission and recording are often exposed to light or brightness problems and various noise interference,so image restoration is an important step in image processing.With the rapid development of micro electronic technology,the software can not meet the requirements of real-time image processing.then FPGA and other Programmable Logic Devices the ideal choice for the hardware to deal with real-time video image data.The research of image processing system based on FPGA will become a hot topic in the field of information industry at home and abroad.And at the same,with the development of VLSI technology,the system integrated chip SOC will become the general trend of development.At first,this paper analyzes the development of video processing technology at home and abroad,introduces Some conventional algorithms of digital image preprocessing,and describes the advantages and disadvantages of using FPGA chip as the core chip of image restoration processing system.According to the design requirements of the real-time image restoration processing,the FPGA based real-time video image restoration processing system can be implemented.The control logic of the peripheral interface,the chip control logic and the algorithm processing module of the whole system is realized by a FPGA chip,which forms a simple and extensible system on programmable chip(SOC).The whole system is realized with real-time image acquisition,image preprocessing function and the display of the FPGA subsystem.The system is consisted of the central processor the Altera's FPGA chip,the image acquisition module,asynchronous FIFO module,image frame storage control module,and digital image processing module.The image sensor OV7725 is responsible for the real-time acquisition of image under the control of FPGA.Two pieces of SDRAM as the video image of the external buffer,its sampling control and filtering algorithm will be implemented in the FPGA.The system in the entire hardware architecture basically realized the median filtering,sequential filtering,mathematical morphology,convolution algorithm and Gauss filter and other digital image processing algorithms.Taking the complexity of the algorithm and the real time into account,in order to effectively exploit the parallelism of the algorithm,the improved median filtering algorithm is used as the restoration algorithm in the part of image processing algorithm,,which improves the processing speed of the module.First of all,the 3*3 square form module is replaced by the 3*3 cross form module.Then combined with the characteristics of FPGA chip self parallel processing,using Verilog language to switch existing bubble sort of median filtering algorithm to parity exchange sort of parallel algorithm which make algorithm improved in both hardware and software programming.The whole design and each module were developed in the development environment of Aletar Quartus?9.1 and third party simulation software Modelsim.And simulation is the combination of them,too.The design choose FPGA ship EP2C35F672C6 that belongs to the company Altera.The simulation results show that using FPGA hardware image processing can not only obtain the very good processing effect,achieve a higher work frequency,but also a far higher processing speed than the software method of image processing,which meets the requirements of real-time video image processing speed.