The Infrared Image Acquisition Based On FPGA And Layered Enhancement Processing Technology Research

Infrared technology is widely used in military,fire control,medical,monitoring and other fields.With the development of the embedded technology and the uncooled focal plane array detector,research and design intelligent,miniaturization,low power consumption of the infrared image acquisition system is the development trend of infrared technology.Original image is not suitable for the human eye observation and post-processing because with the problems of high wide,low contrast,fuzzy edge,so must study according to the characteristics of infrared image data algorithm to enhance its processing.According to the principle of infrared image imaging,refer to related embedded infrared image acquisition system and infrared image processing related papers,designed the infrared image acquisition system based on FPGA embedded hardware platform using the uncooled focal plane infrared detector as infrared radiation sensor.According to the technical index of focal plane array detector,design the voltage bias circuit,timing drive,modulus conversion circuit and convert the infrared radiation to parallel digital signal for easy processing.To gather and deal with the infrared focal plane detector output image signal,design the FPGA driver circuit,random storage and FLASH circuit.The whole hardware system is small in size,low-power dissipation,collecting infrared image raw data successfully.Infrared image acquisition system output for 14 wide dynamic range image,effective information generally focus on narrow grayscale range,is not conducive to the human eye observation and equipment,so the infrared image enhancement is a key link in the system of image processing.In this paper,combined with the requirement of real-time performance and low power consumption of embedded system platform,suggest improvements for layered algorithm based on bilateral filter is easy to appear gradient inversion and the problem of high computational complexity,put forward the hierarchical processing based on guide filter.To the halo of guide filter,uses the LoG operator to constrain filter for a hierarchical processing,successfully eliminate the phenomenon of the halo.Using platform histogram for image contrast enhancement and dynamic range compression at the grass-roots level,and using laplacian sharpen features of image edge.Using gamma correction to image enhancement and suppress the noise at the detail layer,finally make the grassroots image and detail layer linear weighted fusion.This paper designed and implemented the infrared image acquisition system hardware platform,in view of the characteristics of low contrast and large dynamic range,combined with the engineering practicability,designed the infrared image enhancement algorithm based on adaptive guidance filter,the results show that this algorithm can effectively improve the infrared image contrast,enhance image details,and easy to project implementation.