An FPGA-based Real-time Image Processing System For Security Inspection Equipment

Safety is the basic guarantee of life,and the security machine has become an indispensable equipment in public places.Because of the limited storage space and slow operation speed of the software,the image processing algorithms implemented by the traditional security inspection machine are all spatial image processing.In the frequency domain,image processing is more intuitive than spatial filtering,and can greatly reduce the complexity of the algorithm.this topic chooses the FPGA as the system platform to do frequency domain image processing for the image collected by the security inspection machine.The algorithm includes two FFT and frequency domain filtering.The processed image is transmitted to the industrial computer display of security inspection machine in real time through ethernet.In this paper,the system structure of image processing of security inspection machine and the resource occupancy of the implementation of FPGA are optimized.In the system structure,the frame structure of image processing system is built by using the design thinking of pipeline and parallel operation,which speeds up the processing speed of the system.In terms of resource occupancy,by adding logical design of data selector to butterfly operation module and cooperating with timing control,nearly 50% multiplier and addition resources in traditional FFT algorithm are simplified.Verilog is used to write programs on Quartus,and modular design is used to implement image processing algorithm.The corresponding RTL level hardware circuit is obtained.Ethernet is chosen to realize real-time data transmission.Using FPGA as the main control chip,using MAC IP core to connect PHY chip to realize real-time image transmission to PC through UDP protocol.The function simulation of the system is completed by combining.Modelsim and MATLAB,and the board-level system is validated by signaltap.The data transmission of Ethernet is validated by Wireshark on the host computer.The system validation shows that the noise is effectively suppressed and the image is clear,smooth and easy to recognize from the output image of the upper computer of the security inspection machine.Meanwhile,the transmission speed of Ethernet reaches 10 Mbps.The system satisfies the requirement of real-time image processing of security inspection machine.