The Research Of Infrared Image Enhancement Processing Based On FPGA

With the rapid development of infrared technology, infrared imaging system iswidely used in the fields of military, medical, security and people’s daily lives. It showsthe huge market application prospect. However, due to the limitation of the infrareddetector itself and the influence of detection environment, the imaging effect of infraredimaging system is not ideal and not fully playing the advantages of infrared imagingdevice. But the image processing based on sofware is unable to meet the demand ofreal-time, high efficiency. One of the most economic and the most effective way to solvethe above problems is to add real-time image processing function to the thermal imageinstrument electronic processing part. But the field programmable gata array (FPGA) hasbeen widely used in the application of programmable logic devices and the hardware canbe implemented in parallel and pipeline processing technology. These provide a reliablefoundation for the infrared image processing hardware. Therefore, the study of infraredimaging system processing and post-image enhancement has important practicalsignificance and economic value. The main contents of this dissertation are summarized asfollows:Firstly, the basic characteristics of infrared imaging and basic algorithm in spacedomain of the image enhancement processing was studied in this paper, and the effect ofthe algorithm were compared.Secondly, it is proposed to CYCLONEⅡas the core of the infrared image processingsystem according to the stucture characteristics of the FPGA design and developmentprocess and is completed the construction of the whole test system. The processing systemconsists of Rebong Company Photon320thermal imaging movement, video decoder chipSAA7113, two high speed SDRAM and iamge display chip ADV7123. It complete thevideo decoder chip SAA7113configuration. The SDRAM controller module is alsodesigned to control the two pieces of ping-pong operation mode of SDRAM to datatransmission and storage. Finally, the VGA display module is configured to displayreal-time infrared image acquisition. Finally, for infrared images with low contrast detail to identify unobvious problem, acombination algorithm based on histogram equalization and piecewise lineartransformation is proposed to adapt the characteristics of the human eye and improve thevisual effects. Meanwhile, after the study of the infrared filter algorithm, an improvedalgorithm is proposed for a fast median filter suitable for FPGA implementation. Toenhance infrared image edge information, focusing on the Laplacian sharpeningalgorithms, an improved algorithm is proposed for constrained Laplacian sharpening.Related algorithms performe logic design by the FPGA and the result indicates a bettereffect.