基于FPGA的频域幸运成像算法  

FPGA-based Lucky Imaging Algorithm in Frequency Domain

作　　者：黄学明 李彬华[1,2] 王锦良 Huang Xueming;Li Binhua;Wang Jinliang(Faculty of Information Engineering and Automation, Kunming University of Science and Technology, Kunming 650500, China;Key Laboratory of Applications of Computer Technology of Yunnan Province, Kunming University of Science and Technology, Kunming 650500, China)

机构地区：[1]昆明理工大学信息工程与自动化学院,云南昆明650500 [2]昆明理工大学云南省计算机应用技术重点实验室,云南昆明650500

出　　处：《天文研究与技术》2022年第3期253-263,共11页Astronomical Research & Technology

基　　金：国家自然科学基金(11673009)资助.

摘　　要：幸运成像技术是一种事后图像恢复技术,能够有效减小大气湍流对图像质量的影响。传统的频域幸运成像算法的效果优于空域算法,主要由图像预处理、数据选择和数据叠加3部分组成。提出了一种基于现场可编程门阵列(Field-Programmable Gate Array,FPGA)的频域幸运成像算法,并在现场可编程门阵列上构建了频域幸运成像的实验系统。本系统通过将二维转换为两个一维的处理方式对天文图像数据进行二维快速傅里叶变换(2D-FFT),采用频域数据的实部平方与虚部平方之和代替幅值进行数据选择,得到的高分辨率图像与基于中央处理器(Central Processing Unit,CPU)算法处理的结果基本相同。本实验系统能对2000帧128×128像素的图像进行频域幸运成像处理,比传统的基于中央处理器频域幸运成像算法速度快13倍多,实现了对传统频域幸运成像算法的加速,同时也为将来频域幸运成像的实时化提供了一种可行的技术方案。Lucky imaging is a post-processing image restoration technique,which can effectively reduce the impact of atmospheric turbulence on image quality.The traditional frequency-domain lucky imaging algorithm is better than the traditional space-domain lucky imaging algorithm in imaging results.It mainly consists of three parts:image preprocessing,data selection and data superposition.This paper presented a FPGA-based lucky imaging algorithm in frequency domain,and built an experimental system on FPGA.This system implements two-dimensional fast Fourier transform(2D-FFT)on astronomical image data by converting two-dimensional to two one-dimensional processing methods;And the sum of the square of the real part and the square of the imaginary part of the frequency data is used to replace the amplitude for data selection.The obtained high-resolution image reconstructed by the FPGA system is basically the same with the image processed by the CPU platform.The experimental system can process 2000 frames of 128×128 pixels image in frequency domain,what′s more,the processing speed of the system on FPGA is 13 times faster than that on CPU.It accelerates the traditional frequency-domain lucky imaging algorithm while provides a feasible technical scheme for the real-time frequency-domain lucky imaging techniques in the future.

关 键 词：幸运成像 大气湍流 2D-FFT 频域 现场可编程门阵列 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]